Index: /trunk/docs/workshop/2010/building_wps_client_using_ol.txt =================================================================== --- /trunk/docs/workshop/2010/building_wps_client_using_ol.txt (revision 261) +++ /trunk/docs/workshop/2010/building_wps_client_using_ol.txt (revision 262) @@ -2,5 +2,5 @@ Building a WPS client using OpenLayers -############################### +###################################### .. contents:: Table of Contents @@ -8,10 +8,14 @@ :backlinks: top -The next step of our workshop is to connect to the OGR Services we have created from an OpenLayers map. This will allow to apply single or multiple geometries processes on user-selected polygons and to display the new generated geometries. +The next step of our workshop is to connect to the OGR Services we have created +from an OpenLayers map. This will allow to apply single or multiple geometries +processes on user-selected polygons and to display the new generated geometries. Creating a simple map showing the dataset as WMS -****************************************************** - -OpenLayers is also included in OSGeoLive default distribution, so it is convenient to use it for our needs. Please open ``/var/www/zoo-ogr.html`` using your favorite text editor and paste the following HTML snippet: +************************************************ + +OpenLayers is also included in OSGeoLive default distribution, so it is convenient +to use it for our needs. Please open ``/var/www/zoo-ogr.html`` using your favorite +text editor and paste the following HTML snippet: .. code-block:: guess @@ -32,5 +36,6 @@ -The following JavaScript code must then be added in a ```` section within the ```` one. This will setup a map showing the japanese regions data as WMS. +The following JavaScript code must then be added in a ```` section within the +```` one. This will setup a map showing the japanese regions data as WMS. .. code-block:: guess @@ -65,5 +70,7 @@ } -Once done, please save your HTML file as ``zoo-ogr.html`` in your workshop directory, then copy it in ``/var/www`` and visualize it with your favorite Web browser using this link : ``http://localhost/zoo-ogr.html``. You should obtain a map centered on the Japan with the WMS layer activated. +Once done, please save your HTML file as ``zoo-ogr.html`` in your workshop directory, +then copy it in ``/var/www`` and visualize it with your favorite Web browser using this link : +``http://localhost/zoo-ogr.html``. You should obtain a map centered on the Japan with the WMS layer activated. .. image:: ./images/OL-JP-1.png @@ -73,7 +80,10 @@ Fetching the data layer as WFS and adding selection controls -**************************************************************** - -Before accessing the displayed data via WFS, you first have to create new vector layers dedicated to host the several interactions we are going to create. Please add the following lines within the ``init()`` function, and do not forget to add the newly created layer in the map.addLayers method: +************************************************************ + +Before accessing the displayed data via WFS, you first have to create new vector layers +dedicated to host the several interactions we are going to create. Please add the following +lines within the ``init()`` function, and do not forget to add the newly created layer in +the map.addLayers method: .. code-block:: guess @@ -96,5 +106,7 @@ map.addLayers([layer, select, hover, multi]); -Then, you can now access the data by creating new controls to select polygons, as the following. Please note that ``OpenLayers.Protocol.WFS.fromWMSLayer`` is used to access geometries and that several state of selection are declared and append to the control variable. +Then, you can now access the data by creating new controls to select polygons, as the +following. Please note that ``OpenLayers.Protocol.WFS.fromWMSLayer`` is used to access +geometries and that several state of selection are declared and append to the control variable. .. code-block:: guess @@ -122,5 +134,6 @@ control.activate(); -Please save your HTML file again. You should now be able to select a polygon only by clicking on it. The selected polygon should appear in blue color. +Please save your HTML file again. You should now be able to select a polygon only by +clicking on it. The selected polygon should appear in blue color. .. image:: ./images/OL-JP-2.png @@ -130,7 +143,10 @@ Calling the single geometry services from JavaScript -******************************************************* - -Now that everything is setup, we can go on and call our OGR ZOO services with JavaScript. Please add the following lines after the ``init()`` function, which will call the single geometry processes. You can notice that we use a specific ``parseMapServerId`` function which let us remove the unecessary white space returned as fid value. +**************************************************** + +Now that everything is setup, we can go on and call our OGR ZOO services with JavaScript. +Please add the following lines after the ``init()`` function, which will call the single +geometry processes. You can notice that we use a specific ``parseMapServerId`` function +which let us remove the unecessary white space returned as fid value. .. code-block:: guess @@ -175,5 +191,7 @@ -Then, some specific buttons must be added in the HTML, in order to be able to call the different processes we just declared. You can add them on top of the map by writing the following lines before the ``
``. +Then, some specific buttons must be added in the HTML, in order to be able to call +the different processes we just declared. You can add them on top of the map by writing +the following lines before the ``
``. .. code-block:: guess @@ -198,5 +216,7 @@ -Save your HTML file again. You should now be able to select a polygon and to launch a Buffer, ConvexHull, Boundary or Centroid on it by clicking one of the button. The result of the process should appear as GeoJSON layer on the map, in orange color. +Save your HTML file again. You should now be able to select a polygon and to launch a Buffer, +ConvexHull, Boundary or Centroid on it by clicking one of the button. The result of the +process should appear as GeoJSON layer on the map, in orange color. .. image:: ./images/OL-JP-3.png @@ -206,7 +226,9 @@ Calling the multiples geometries processes from JavaScript -************************************************************** - -Using the same technique, you can now write a function dedicated to the multiple geometries processes. Please add the following lines after the ``simpleProcessing()`` function, we will guide you during the exercise in section 5 on how to create such a function. +********************************************************** + +Using the same technique, you can now write a function dedicated to the multiple geometries +processes. Please add the following lines after the ``simpleProcessing()`` function, we will +guide you during the exercise in section 5 on how to create such a function. .. code-block:: guess @@ -261,7 +283,11 @@ } -Note that this time we didn't use the GET method to request the ZOO Kernel but a XML POST. We did that because if you use the GET method you will get error due to the HTTP GET method limitation based on the length of your request. Using JSON string representing the geometry will make your request longer. - -Once you get the functions to call your multiple geometries processes, you' must add some buttons to fire the request call. Here is the HTML code to add to your current ``zoo-ogr.html`` file : +Note that this time we didn't use the GET method to request the ZOO Kernel but a XML POST. +We did that because if you use the GET method you will get error due to the HTTP GET method +limitation based on the length of your request. Using JSON string representing the geometry +will make your request longer. + +Once you get the functions to call your multiple geometries processes, you' must add some +buttons to fire the request call. Here is the HTML code to add to your current ``zoo-ogr.html`` file : .. code-block:: guess @@ -283,5 +309,6 @@ -Please reload the page. You should then be able to run your multiple geometries services and you should get results displayed in red as shown by the following screenshots : +Please reload the page. You should then be able to run your multiple geometries services and +you should get results displayed in red as shown by the following screenshots : @@ -299,3 +326,4 @@ :height: 140px -It seems that something is missing in your Services Provider to get the same results … The multiple geometries Services ! This is what we are going to do together in the next section. +It seems that something is missing in your Services Provider to get the same results … +The multiple geometries Services ! This is what we are going to do together in the next section. Index: /trunk/docs/workshop/2010/exercise.txt =================================================================== --- /trunk/docs/workshop/2010/exercise.txt (revision 261) +++ /trunk/docs/workshop/2010/exercise.txt (revision 262) @@ -2,7 +2,9 @@ Exercise -####### +######## -You know everything now about writting zcfg matadata files and get short pieces of code in ``service.c`` or ``ogr_service_provider.py`` depending if you choosen C or Python programming language respectively. +You know everything now about writting zcfg matadata files and get short pieces +of code in ``service.c`` or ``ogr_service_provider.py`` depending if you choosen +C or Python programming language respectively. The goal of this exercise is to implement the following multiple geometries services : @@ -14,7 +16,8 @@ C version -********** +********* -Your are now invited to edit the source.c file you have created during this workshop to add the multiple geometries, using the following OGR C-API functions : +Your are now invited to edit the source.c file you have created during this workshop +to add the multiple geometries, using the following OGR C-API functions : - `OGR_G_Intersection `__ (OGRGeometryH, OGRGeometryH) @@ -23,10 +26,15 @@ - `OGR_G_SymmetricDifference `__ (OGRGeometryH, OGRGeometryH) -You can use the ``Boundary.zcfg`` file as example, rename the InputPolygon input to ``InputEntity1`` and add a similar input named ``IntputEntity2``. You are invited to update other values in the ZOO Metadata File to set the proper metadata informations. +You can use the ``Boundary.zcfg`` file as example, rename the InputPolygon input +to ``InputEntity1`` and add a similar input named ``IntputEntity2``. You are +invited to update other values in the ZOO Metadata File to set the proper +metadata informations. Python Version -**************** +************** -Your are invited to edit the ``ogr_ws_service_provider.py`` file you created during this workshop to add the multiple geometries using the following ``osgeo.ogr`` Geometry methods applied on the first Geometry instance : +Your are invited to edit the ``ogr_ws_service_provider.py`` file you created +during this workshop to add the multiple geometries using the following +``osgeo.ogr`` Geometry methods applied on the first Geometry instance : - Intersection(Geometry) @@ -35,9 +43,14 @@ - SymmetricDifference(Geometry) -You can once again use the ``Boundary.zcfg`` file as example, rename the ``InputPolygon`` input to ``InputEntity1`` and add a similar input named ``IntputEntity2``. You are invited to update other values in the ZOO metadata file to set the proper metadata informations. +You can once again use the ``Boundary.zcfg`` file as example, rename the ``InputPolygon`` +input to ``InputEntity1`` and add a similar input named ``IntputEntity2``. You are +invited to update other values in the ZOO metadata file to set the proper metadata +informations. Testing your services -*********************** +********************* -Once the multiple geometries Services are deployed on your local environment, please reload the ``zoo-ogr.html`` file created during the previous section from your browser and test your brand new ZOO Services. +Once the multiple geometries Services are deployed on your local environment, +please reload the ``zoo-ogr.html`` file created during the previous section +from your browser and test your brand new ZOO Services. Index: /trunk/docs/workshop/2010/introduction.txt =================================================================== --- /trunk/docs/workshop/2010/introduction.txt (revision 261) +++ /trunk/docs/workshop/2010/introduction.txt (revision 262) @@ -2,5 +2,5 @@ Introduction -########## +############ .. contents:: Table of Contents @@ -9,5 +9,5 @@ What is ZOO ? -*************** +************* ZOO is a WPS (Web Processing Service) open source project recently released under a `MIT/X-11 `__ style license. It provides an OGC WPS compliant developer-friendly framework to create and chain WPS Web services. ZOO is made of three parts: @@ -17,23 +17,62 @@ - `ZOO API `__ : A server-side JavaScript API able to call and chain the ZOO Services, which makes the development and chaining processes easier. -ZOO is designed to make the service development easier by providing a powerful system able to understand and execute WPS compliant queries. It supports several programming languages, thus allowing you to create Web Services in your favorite one and from an already existing code. Further information on the project is available on the `ZOO Project official website `__ . +ZOO is designed to make the service development easier by providing a powerful system +able to understand and execute WPS compliant queries. It supports several programming +languages, thus allowing you to create Web Services in your favorite one and from an +already existing code. Further information on the project is available on the +`ZOO Project official website `__ . How does ZOO works ? -************************ +******************** -ZOO is based on a 'WPS Service Kernel' which constitutes the ZOO's core system (aka ZOO Kernel). The latter is able to load dynamic libraries and to handle them as on-demand Web services. The ZOO Kernel is written in C language, but supports several common programming languages for creating ZOO Services. +ZOO is based on a 'WPS Service Kernel' which constitutes the ZOO's core system +(aka ZOO Kernel). The latter is able to load dynamic libraries and to handle them +as on-demand Web services. The ZOO Kernel is written in C language, but supports +several common programming languages for creating ZOO Services. -A ZOO Service is a link composed of a ZOO metadata file (.zcfg) and the code for the corresponding implementation. The metadata file describes all the available functions which can be called using a WPS Exec Request, as well as the desired input/output. Services contain the algorithms and functions, and can now be implemented in C/C++, Fortran, Java, Python, Perl, PHP and JavaScript. +A ZOO Service is a link composed of a ZOO metadata file (.zcfg) and the code for +the corresponding implementation. The metadata file describes all the available +functions which can be called using a WPS Exec Request, as well as the desired +input/output. Services contain the algorithms and functions, and can now be +implemented in C/C++, Fortran, Java, Python, Perl, PHP and JavaScript. -ZOO Kernel works with Apache and can communicate with cartographic engines and Web mapping clients. It simply adds the WPS support to your spatial data infrastructure and your Web mapping application. It can use every GDAL/OGR supported formats as input data and create suitable vector or raster output for your cartographic engine and/or your web-mapping client application. +ZOO Kernel works with Apache and can communicate with cartographic engines and +Web mapping clients. It simply adds the WPS support to your spatial data infrastructure +and your Web mapping application. It can use every GDAL/OGR supported formats as input +data and create suitable vector or raster output for your cartographic engine and/or +your web-mapping client application. What are we going to do in this workshop? -********************************************* +***************************************** -This workshop aims to present the ZOO Project and its features, and to explain its capabilities regarding the `OGC WPS 1.0.0 specification `__. The participants will learn in 3 hours how to use ZOO Kernel, how to create ZOO Services and their configuration files and finally how to link the created Service with a client-side webmapping application. A pre-compiled ZOO 1.0 version is provided inside OSGeoLive, the OSGeo official Live DVD. For the sack of simplicity, an OSGeoLive Virtual Machine image disk is already installed on your computers. This will be used during this workshop, so the participants won't have to compile and install ZOO Kernel manually. Running and testing ZOO Kernel from this OSGeoLive image disk is thus the first step of the workshop, and every participants should get a working ZOO Kernel in less than 30 minutes. +This workshop aims to present the ZOO Project and its features, and to explain its +capabilities regarding the `OGC WPS 1.0.0 specification `__. +The participants will learn in 3 hours how to use ZOO Kernel, how to create +ZOO Services and their configuration files and finally how to link the created +Service with a client-side webmapping application. A pre-compiled ZOO 1.0 version +is provided inside OSGeoLive, the OSGeo official Live DVD. For the sack of simplicity, +an OSGeoLive Virtual Machine image disk is already installed on your computers. +This will be used during this workshop, so the participants won't have to compile +and install ZOO Kernel manually. Running and testing ZOO Kernel from this OSGeoLive +image disk is thus the first step of the workshop, and every participants should +get a working ZOO Kernel in less than 30 minutes. -Once ZOO Kernel will be tested from a Web browser using GetCapabilities requests, participants will be invited to create an OGR based ZOO Service Provider aiming to enable simple spatial operations on vector data. Participants will first have to choose whether they will create the service using C or Python language. Every programming step of the ZOO Service Provider and the related Services will be each time detailed in C and Python. Once the ZOO Services will be ready and callable by ZOO Kernel, participants will finally learn how to use its different functions from an OpenLayers simple application. A sample dataset was providen by Orkney and included in the OSGeoLiveDVD, data are available trough OGC WMS/WFS WebServices using MapServer and will be displayed on a simple map and used as input data by the ZOO Services. Then, some specific selection and execution controls will be added in the JavaScript code in order to execute single and multiple geometries on the displayed polygons. +Once ZOO Kernel will be tested from a Web browser using GetCapabilities requests, +participants will be invited to create an OGR based ZOO Service Provider aiming to +enable simple spatial operations on vector data. Participants will first have to +choose whether they will create the service using C or Python language. Every programming +step of the ZOO Service Provider and the related Services will be each time detailed in +C and Python. Once the ZOO Services will be ready and callable by ZOO Kernel, participants +will finally learn how to use its different functions from an OpenLayers simple application. +A sample dataset was providen by Orkney and included in the OSGeoLiveDVD, data are +available trough OGC WMS/WFS WebServices using MapServer and will be displayed on a +simple map and used as input data by the ZOO Services. Then, some specific selection +and execution controls will be added in the JavaScript code in order to execute single +and multiple geometries on the displayed polygons. -Once again, the whole procedure will be organized step-by-step and detailed with numerous code snippets and their respective explanations. The instructors will check the ZOO Kernel functioning on each machine and will assist you while coding. Technical questions are of course welcome during the workshop. +Once again, the whole procedure will be organized step-by-step and detailed with +numerous code snippets and their respective explanations. The instructors will check +the ZOO Kernel functioning on each machine and will assist you while coding. Technical +questions are of course welcome during the workshop. Usefull tips for reading : Index: /trunk/docs/workshop/2010/ogr_base_vect_ops.txt =================================================================== --- /trunk/docs/workshop/2010/ogr_base_vect_ops.txt (revision 261) +++ /trunk/docs/workshop/2010/ogr_base_vect_ops.txt (revision 262) @@ -2,5 +2,5 @@ Creating OGR based Web Services -########################## +############################### .. contents:: Table of Contents @@ -9,16 +9,32 @@ Introduction -************* - -In this part, we are going to create a ZOO ServicesProvider containing several Services based on the OGR C API or on the OGR Python module, which have also been placed in the ZOO installation on OSGeoLive. The intended goal is to use OGR and its GEOS based simple spatial functions as WPS Services. - -We will first start with the Boundary spatial function, which will be explained, codded and tested gradually as a ZOO Service. The same procedure will then be used to enable the Buffer, Centroid and Convex Hull functions. Once done, some multiple geometries processes such as Intersection, Union, Difference and Symetric Difference will be implemented through an `exercise <./exercise.html>`__ at the end of the workshop. - -As already said in the introduction, you have the choice to code your service in C or Python (or both!) during this workshop. Explanations will be based on the C part, but will be very helpful for those who will choose Python. Please decide according to your habits and preferences and tell your choice to the instructors. The results will be the same in both case. +************ + +In this part, we are going to create a ZOO ServicesProvider containing several Services +based on the OGR C API or on the OGR Python module, which have also been placed in the +ZOO installation on OSGeoLive. The intended goal is to use OGR and its GEOS based simple +spatial functions as WPS Services. + +We will first start with the Boundary spatial function, which will be explained, codded +and tested gradually as a ZOO Service. The same procedure will then be used to enable +the Buffer, Centroid and Convex Hull functions. Once done, some multiple geometries processes +such as Intersection, Union, Difference and Symetric Difference will be implemented through +an `exercise <./exercise.html>`__ at the end of the workshop. + +As already said in the introduction, you have the choice to code your service in C or +Python (or both!) during this workshop. Explanations will be based on the C part, but +will be very helpful for those who will choose Python. Please decide according to your +habits and preferences and tell your choice to the instructors. The results will be the +same in both case. Preparing ZOO metadata file -****************************** - -A ZOO Service is a combination of a ZOO metadata file (``.zcfg``) and the runtime module for the corresponding implementation, which is commonly called ZOO Service Provider. We will first prepare a ``.zcfg`` file step-by-step. Please open your preferred text editor and edit a file named ``Boundary.zcfg`` in your ``/home/user/zoows/sources/zoo-services/ws_sp`` directory. First, you need to name the service between brackets at the top of the file, as the following +*************************** + +A ZOO Service is a combination of a ZOO metadata file (``.zcfg``) and the runtime module +for the corresponding implementation, which is commonly called ZOO Service Provider. We +will first prepare a ``.zcfg`` file step-by-step. Please open your preferred text editor +and edit a file named ``Boundary.zcfg`` in your ``/home/user/zoows/sources/zoo-services/ws_sp`` +directory. First, you need to name the service between brackets at the top of the file, as the +following :: @@ -26,5 +42,7 @@ [Boundary] -This name is very important, it is the name of the Service and so the name of the function defined in the Services Provider. A title and a brief abstract must then be added to inform clients on what the service can do: +This name is very important, it is the name of the Service and so the name of the function +defined in the Services Provider. A title and a brief abstract must then be added to inform +clients on what the service can do: .. code-block:: guess @@ -35,5 +53,8 @@ Such metadata informations will be returned by a GetCapabilities request. -You can also add other specific informations like the ``processVersion``. You can set if your ZOO Service can store its results, by setting the ``storeSupported`` parameter to true or false. You can also decide if the function can be run as a background task and inform on its current status, according to the ``statusSupported`` value : +You can also add other specific informations like the ``processVersion``. You can set if +your ZOO Service can store its results, by setting the ``storeSupported`` parameter to +true or false. You can also decide if the function can be run as a background task and +inform on its current status, according to the ``statusSupported`` value : .. code-block:: guess @@ -55,5 +76,6 @@ serviceType=C -In this case you will get an ``ogr_ws_service_provider.zo`` shared library containing the Boundary function, placed in the same directory than ZOO Kernel. +In this case you will get an ``ogr_ws_service_provider.zo`` shared library containing +the Boundary function, placed in the same directory than ZOO Kernel. Python ServicesProvider Example : @@ -74,7 +96,16 @@ -The main metadata informations have been declared, so you can now define data input which will be used by the ZOO Service. You can define any input needed by the Service. Please note that you can request ZOO Kernel using more data input than defined in the ``.zcfg`` file without any problem, those values will be passed to your service without filtering. In the Boundary Service example, a single polygon will be used as input, the one on which to apply the Boundary function. - -The data input declarations are included in a DataInputs block. They use the same syntax as the Service itself and the input name is between brackets. You can also fill a title, an abstract and a MetaData section for the input. You must set values for the ``minOccurs`` and ``maxOccurs`` parameters, as they will inform ZOO Kernel which parameters are required to be able to run the Service function. +The main metadata informations have been declared, so you can now define data input +which will be used by the ZOO Service. You can define any input needed by the Service. +Please note that you can request ZOO Kernel using more data input than defined in +the ``.zcfg`` file without any problem, those values will be passed to your service +without filtering. In the Boundary Service example, a single polygon will be used as +input, the one on which to apply the Boundary function. + +The data input declarations are included in a DataInputs block. They use the same +syntax as the Service itself and the input name is between brackets. You can also +fill a title, an abstract and a MetaData section for the input. You must set values +for the ``minOccurs`` and ``maxOccurs`` parameters, as they will inform ZOO Kernel +which parameters are required to be able to run the Service function. .. code-block:: none @@ -90,5 +121,9 @@ -The metadata defines what type of data the Service supports. In the Boundary example, the input polygon can be provided as a GML file or as a JSON string. Next step is thus to define the default and supported input formats. Both formats should be declared in a LitteralData or ComplexData block depending on their types. For this first example we will use ComplexData blocks only. +The metadata defines what type of data the Service supports. In the Boundary example, +the input polygon can be provided as a GML file or as a JSON string. Next step is +thus to define the default and supported input formats. Both formats should be declared +in a LitteralData or ComplexData block depending on their types. For this first example +we will use ComplexData blocks only. .. code-block:: guess @@ -130,5 +165,7 @@ -Once the ZOO metadata file is modified, you have to copy it in the same directory than your ZOO Kernel (so in your case ``/usr/lib/cgi-bin``). Then you should be able to run the following request : +Once the ZOO metadata file is modified, you have to copy it in the same directory +than your ZOO Kernel (so in your case ``/usr/lib/cgi-bin``). Then you should be +able to run the following request : http://localhost/zoo/?Request=DescribeProcess&Service=WPS&Identifier=Boundary&version=1.0.0 @@ -141,5 +178,7 @@ :align: center -Please note that the GetCapabilities and DescribeProcess only need a ``.zcfg`` file to be completed. Simple, isn't it ? At this step, if you request ZOO Kernel for an Execute, you will get an ExceptionReport document as response, looking as the following : +Please note that the GetCapabilities and DescribeProcess only need a ``.zcfg`` +file to be completed. Simple, isn't it ? At this step, if you request ZOO Kernel +for an Execute, you will get an ExceptionReport document as response, looking as the following : .. image:: ./images/Practical-introduction-to-ZOO-6.png @@ -157,9 +196,15 @@ Implementing single geometry services -***************************************** - -In order to learn the Services Provider creation and deployement step-by-step, we will first focus on creating a very simple one dedicated to the Boundary function. Similar procedure will then be used for the Buffer, Centroid and ConvexHull implementation. - -Your metadata is now ok, so you now must create the code of your Service. The most important thing you must be aware of when coding ZOO Services is that the function corresponding to your Service takes three parameters (internal maps datatype or `Python dictionaries `__) and returns an integer value representing the status of execution (SERVICE_FAILED or SERVICE_SUCCEEDED): +************************************* + +In order to learn the Services Provider creation and deployement step-by-step, +we will first focus on creating a very simple one dedicated to the Boundary function. +Similar procedure will then be used for the Buffer, Centroid and ConvexHull implementation. + +Your metadata is now ok, so you now must create the code of your Service. The most +important thing you must be aware of when coding ZOO Services is that the function +corresponding to your Service takes three parameters (internal maps datatype or +`Python dictionaries `__) +and returns an integer value representing the status of execution (SERVICE_FAILED or SERVICE_SUCCEEDED): - ``conf`` : The main environment configuration (corresponding to the ``main.cfg`` content) @@ -168,12 +213,16 @@ Boundary -====== +======== C Version --------- - -As explained before, ZOO Kernel will pass the parameters to your Service function in a specific datatype called maps. In order to code your Service in C language, you also need to learn how to access this datatype in read/write mode. - -The maps are simple map named linked list containing a name, a content map and a pointer to the next map in the list (or NULL if there is no more map in the list). Here is the datatype definition as you can find in the zoo-kernel/service.h file: +--------- + +As explained before, ZOO Kernel will pass the parameters to your Service function +in a specific datatype called maps. In order to code your Service in C language, +you also need to learn how to access this datatype in read/write mode. + +The maps are simple map named linked list containing a name, a content map and a +pointer to the next map in the list (or NULL if there is no more map in the list). +Here is the datatype definition as you can find in the zoo-kernel/service.h file: .. code-block:: c @@ -185,5 +234,7 @@ } maps; -The map included in the maps is also a simple linked list and is used to store Key Value Pair values. A map is thus a couple of name and value and a pointer to the next map in the list. Here is the datatype definition you can find in the zoo-kernel/service.h file: +The map included in the maps is also a simple linked list and is used to store Key +Value Pair values. A map is thus a couple of name and value and a pointer to the +next map in the list. Here is the datatype definition you can find in the zoo-kernel/service.h file: .. code-block:: guess @@ -196,5 +247,9 @@ -As partially or fully filled datastructures will be passed by the ZOO Kernel to your Services, this means that you do not need to deal with maps creation but directly with existing map, in other words the content of each maps. The first function you need to know is getMapFromMaps (defined in the zoo-kernel/service.h file) which let you access to a specific map of a maps. +As partially or fully filled datastructures will be passed by the ZOO Kernel to +your Services, this means that you do not need to deal with maps creation but +directly with existing map, in other words the content of each maps. The first +function you need to know is getMapFromMaps (defined in the zoo-kernel/service.h file) +which let you access to a specific map of a maps. This function takes three parameters listed bellow: @@ -204,5 +259,6 @@ - ``key`` : a specific key in the map named name -For example, the following syntax will be used to access the InputPolygon value map of a maps named inputs, your C code should be: +For example, the following syntax will be used to access the InputPolygon value +map of a maps named inputs, your C code should be: .. code-block:: guess @@ -217,5 +273,7 @@ tmp->value -As you know how to read and access the map fields from a maps, you can now learn how to write in such a datastructure. This is done by using the simple setMapInMaps function once again defined in zoo-kernel/service.h. The setMapInMaps function takes four parameters : +As you know how to read and access the map fields from a maps, you can now learn +how to write in such a datastructure. This is done by using the simple setMapInMaps +function once again defined in zoo-kernel/service.h. The setMapInMaps function takes four parameters : - ``m`` : a maps pointer you want to update, @@ -233,7 +291,10 @@ -Please note that the setMapInMaps function is able to create or update an existing map. Indeed, if a map called « value » allready exists, then its value will be updated automatically. - -Even if you will mainly use map from maps during this workshop, you can also add or update values in a map directly using the addToMap function defined in zoo-kernel/service.h. The addToMap function take three paramters : +Please note that the setMapInMaps function is able to create or update an existing map. +Indeed, if a map called « value » allready exists, then its value will be updated automatically. + +Even if you will mainly use map from maps during this workshop, you can also add or +update values in a map directly using the addToMap function defined in zoo-kernel/service.h. +The addToMap function take three paramters : - ``m`` : a map pointer you want to update, @@ -241,7 +302,10 @@ - ``v`` : the value you want to set in this map. -This datatype is really important cause it is used in every C based ZOO Services. It is also the same representation used in other languages but using their respectives datatypes. For Example in Python, the dictionaries datatype is used, so manipulation is much easier. - -Here is an example of the correspoding maps datatype used in Python language (this is a summarized version of the main configaration maps): +This datatype is really important cause it is used in every C based ZOO Services. It is +also the same representation used in other languages but using their respectives datatypes. +For Example in Python, the dictionaries datatype is used, so manipulation is much easier. + +Here is an example of the correspoding maps datatype used in Python language (this is a +summarized version of the main configaration maps): .. code-block:: guess @@ -264,5 +328,10 @@ As you know how to deal with maps and map, you are ready to code the first ZOO Service by using the OGR Boundary function. -As already said in introduction we will use the MapServer WFS server available on OSGeoLive, so full WFS Response will be used as inputs values. As we will use the simple OGR Geometry functions like `OGR_G_GetBoundary `__, only the Geometry object will be used rather than a full WFS Response. The first thing to do is to write a function which will extract the geometry definition from the full WFS Response. We will call it createGeometryFromWFS. +As already said in introduction we will use the MapServer WFS server available on +OSGeoLive, so full WFS Response will be used as inputs values. As we will use the +simple OGR Geometry functions like `OGR_G_GetBoundary `__, +only the Geometry object will be used rather than a full WFS Response. The first +thing to do is to write a function which will extract the geometry definition +from the full WFS Response. We will call it createGeometryFromWFS. Here is the code of such a function: @@ -306,5 +375,7 @@ -The only thing we will focus on is the call to the errorException function used in the function body. This function is declared in the zoo-kernel/service_internal.h and defined in zoo-kernel/service_internal.c file. It takes three parameters as follow: +The only thing we will focus on is the call to the errorException function used +in the function body. This function is declared in the zoo-kernel/service_internal.h +and defined in zoo-kernel/service_internal.c file. It takes three parameters as follow: - the main environment maps, @@ -312,7 +383,9 @@ - a char* representing the error code (as defined in the WPS specification – Table 62). -In other words, if the WFS response cannot be parsed properly, then you will return an ExceptionReport document informing the client that a problem occured. - -The function to extract the geometry object from a WFS Response is written, so you can now start defining the Boundary Service. Here is the full code for the Boundary Service: +In other words, if the WFS response cannot be parsed properly, then you will return +an ExceptionReport document informing the client that a problem occured. + +The function to extract the geometry object from a WFS Response is written, so you +can now start defining the Boundary Service. Here is the full code for the Boundary Service: .. code-block:: guess @@ -363,11 +436,23 @@ geometry=createGeometryFromWFS(conf,tmp->value); -Basicaly, if we get an input with a mimeType set to application/json, then we will use our ``OGR_G_CreateGeometryFromJson`` in other case, our ``createGeometryFromWFS`` local function. - -Please note that in some sense the data inputs are not really of the same kind. Indeed as we used directly ``OGR_G_CreateGeometryFromJson`` it means that the JSON string include only the geometry object and not the full GeoJSON string. Nevertheless, you can easily change this code to be able to use a full GeoJSON string, simply by creating a function which will extract the geometry object from the GeoJSON string (using the json-c library for instance, which is also used by the OGR GeoJSON Driver). - -Once you can access the input geometry object, you can use the ``OGR_G_GetBoundary`` function and store the result in the res geometry variable. Then, you only have to store the value in the right format : GeoJSON per default or GML as we declared it as a supported output format. - -Please note that ZOO Kernel will give you pre-filled outputs values, so you will only have to fill the value for the key named value, even if in our example we override the mimeType using the text/plain value rather than the application/json (to show that we can also edit other fields of a map). Indeed, depending on the format requested by the client (or the default one) we will provide JSON or GML representation of the geometry. +Basicaly, if we get an input with a mimeType set to application/json, then we will +use our ``OGR_G_CreateGeometryFromJson`` in other case, our ``createGeometryFromWFS`` local function. + +Please note that in some sense the data inputs are not really of the same kind. +Indeed as we used directly ``OGR_G_CreateGeometryFromJson`` it means that the JSON +string include only the geometry object and not the full GeoJSON string. Nevertheless, +you can easily change this code to be able to use a full GeoJSON string, simply by +creating a function which will extract the geometry object from the GeoJSON string +(using the json-c library for instance, which is also used by the OGR GeoJSON Driver). + +Once you can access the input geometry object, you can use the ``OGR_G_GetBoundary`` +function and store the result in the res geometry variable. Then, you only have to +store the value in the right format : GeoJSON per default or GML as we declared it as a supported output format. + +Please note that ZOO Kernel will give you pre-filled outputs values, so you will +only have to fill the value for the key named value, even if in our example we +override the mimeType using the text/plain value rather than the application/json +(to show that we can also edit other fields of a map). Indeed, depending on the +format requested by the client (or the default one) we will provide JSON or GML representation of the geometry. .. code-block:: guess @@ -386,7 +471,16 @@ } -The Boundary ZOO Service is now implemented and you need to compile it to produce a Shared Library. As you just used functions defined in service.h (``getMapFromMaps``, ``setMapInMaps`` and ``addToMap``), you must include this file in your C code. The same requirement is needed to be able to use the ``errorException`` function declared in ``zoo-kernel/service_internal.h``, you also must link your service object file to the ``zoo-kernel/service_internal.o`` in order to use ``errorException`` on runtime. You must then include the required files to access the libxml2 and OGR C-API. - -For the need of the Shared Library, you have to put your code in a block declared as extern "C". The final Service code should be stored in a service.c file located in the root of the Services Provider directory (so in ``/home/zoows/sources/zoo-services/ws_sp``). It should look like this: +The Boundary ZOO Service is now implemented and you need to compile it to produce +a Shared Library. As you just used functions defined in service.h (``getMapFromMaps``, +``setMapInMaps`` and ``addToMap``), you must include this file in your C code. The +same requirement is needed to be able to use the ``errorException`` function declared +in ``zoo-kernel/service_internal.h``, you also must link your service object file to +the ``zoo-kernel/service_internal.o`` in order to use ``errorException`` on runtime. +You must then include the required files to access the libxml2 and OGR C-API. + +For the need of the Shared Library, you have to put your code in a block declared as +extern "C". The final Service code should be stored in a service.c file located in +the root of the Services Provider directory (so in ``/home/zoows/sources/zoo-services/ws_sp``). +It should look like this: .. code-block:: guess @@ -402,5 +496,6 @@ } -The full source code of your Service is now ready and you must produce the corresponding Service Shared Object by compiling the code as a Shared Library. This can be done using the following command: +The full source code of your Service is now ready and you must produce the corresponding +Service Shared Object by compiling the code as a Shared Library. This can be done using the following command: .. code-block:: guess @@ -410,7 +505,17 @@ Please note that the ``CFLAGS`` and ``LDFLAGS`` environment variables values must be set before. -The ``CFLAGS`` must contain all the requested paths to find included headers, so the path to the directories where the ``ogr_api.h``, ``libxml2`` directory, ``service.h`` and ``service_internal.h`` files are located. Thanks to the OSGeoLive environment, some of the provided tools can be used to retrieve those values : ``xml2-config`` and ``gdal-config``, both used with the ``--cflags`` argument. They will produce the desired paths for you. - -If you follow the instructions to create your ZOO Services Provider main directory in ``zoo-services``, then you should find the ZOO Kernel headers and source tree which is located in the ``../../zoo-kernel`` directory relatively to your current path (``/home/user/zoows/sources/zoo-services/ws_sp``). Note that you can also use a full path to the ``zoo-kernel`` directory but using relative path will let you move your sources tree somewhere else and keep your code compiling using exactly the same command line. So you must add a ``-I../../zoo-kernel`` to your ``CFLAGS`` to make the compiler able to find the ``service.h`` and ``service_internal.h`` files. +The ``CFLAGS`` must contain all the requested paths to find included headers, so the +path to the directories where the ``ogr_api.h``, ``libxml2`` directory, ``service.h`` +and ``service_internal.h`` files are located. Thanks to the OSGeoLive environment, +some of the provided tools can be used to retrieve those values : ``xml2-config`` and +``gdal-config``, both used with the ``--cflags`` argument. They will produce the desired paths for you. + +If you follow the instructions to create your ZOO Services Provider main directory in +``zoo-services``, then you should find the ZOO Kernel headers and source tree which is +located in the ``../../zoo-kernel`` directory relatively to your current path (``/home/user/zoows/sources/zoo-services/ws_sp``). +Note that you can also use a full path to the ``zoo-kernel`` directory but using relative +path will let you move your sources tree somewhere else and keep your code compiling +using exactly the same command line. So you must add a ``-I../../zoo-kernel`` to your +``CFLAGS`` to make the compiler able to find the ``service.h`` and ``service_internal.h`` files. The full ``CFLAGS`` definition should look like this: @@ -420,5 +525,9 @@ CFLAGS=`gdal-config --cflags` `xml2-config --clfags` -I../../zoo-kernel/ -Once you get the included paths correctly set in your ``CFLAGS`` , it is time to concentrate on the library we have to link against (defined in the ``LDFLAGS`` environment variable). In order to link against the gdal and libxml2 libraries, you can use the same tools than above using the ``--libs`` argument rather than ``--cflags``. The full ``LDFLAGS`` definition must look like this : +Once you get the included paths correctly set in your ``CFLAGS`` , it is time to concentrate +on the library we have to link against (defined in the ``LDFLAGS`` environment variable). +In order to link against the gdal and libxml2 libraries, you can use the same tools than +above using the ``--libs`` argument rather than ``--cflags``. The full ``LDFLAGS`` +definition must look like this : .. code-block:: guess @@ -426,5 +535,6 @@ LDFLAGS=`gdal-config --libs` `xml2-config --libs` ../../zoo-kernel/service_internal.o -Let's now create a ``Makefile`` which will help you compiling your code over the time. Please write a short ``Makefile`` in the root of your ZOO Services Provider directory, containing the following lines: +Let's now create a ``Makefile`` which will help you compiling your code over the time. +Please write a short ``Makefile`` in the root of your ZOO Services Provider directory, containing the following lines: .. code-block:: guess @@ -440,7 +550,11 @@ -Using this ``Makefile``, you should be able to run ``make`` from your ZOO Service Provider main directory and to get the resulting ``ogr_ws_service_provider.zo`` file located in the ``cgi-env`` directory. - -The metadata file and the ZOO Service Shared Object are now both located in the ``cgi-env`` directory. In order to deploy your new ServicesProvider, you only have to copy the ZOO Service Shared Object and its corresponding metadata file in the directory where ZOO Kernel is located, so in ``/usr/lib/cgi-bin``. You must use a ``sudo`` command to achieve this task: +Using this ``Makefile``, you should be able to run ``make`` from your ZOO Service Provider +main directory and to get the resulting ``ogr_ws_service_provider.zo`` file located in the ``cgi-env`` directory. + +The metadata file and the ZOO Service Shared Object are now both located in the ``cgi-env`` +directory. In order to deploy your new ServicesProvider, you only have to copy the ZOO +Service Shared Object and its corresponding metadata file in the directory where ZOO +Kernel is located, so in ``/usr/lib/cgi-bin``. You must use a ``sudo`` command to achieve this task: .. code-block:: guess @@ -448,7 +562,10 @@ sudo cp ./cgi-env/* /usr/lib/cgi-bin -You should now understand more clearly the meannings of the ZOO Service Provider source tree ! The ``cgi-env`` directory will let you deploy your new Services or Services Provider in an easy way , simply by copying the whole cgi-env content in your ``cgi-bin`` directory. - -Please note that you can add the following lines to your ``Makefile`` to be able to type ``make install`` directly and to get your new Services Provider available for use from ZOO Kernel: +You should now understand more clearly the meannings of the ZOO Service Provider source tree ! +The ``cgi-env`` directory will let you deploy your new Services or Services Provider in +an easy way , simply by copying the whole cgi-env content in your ``cgi-bin`` directory. + +Please note that you can add the following lines to your ``Makefile`` to be able to type +``make install`` directly and to get your new Services Provider available for use from ZOO Kernel: .. code-block:: none @@ -460,7 +577,10 @@ Python Version ------------- - -For those using Python to implement their ZOO Services Provider, the full code to copy in ``ogr_ws_service_provider.py`` in ``cgi-env`` directory is shown bellow. Indeed, as Python is an interpreted language, you do not have to compile anything before deploying your service which makes the deployement step much easier: +-------------- + +For those using Python to implement their ZOO Services Provider, the full code to copy in +``ogr_ws_service_provider.py`` in ``cgi-env`` directory is shown bellow. Indeed, as +Python is an interpreted language, you do not have to compile anything before deploying +your service which makes the deployement step much easier: .. code-block:: guess @@ -494,5 +614,6 @@ return 3 -We do not dicuss the functions body here as we already gave all the details before and the code was volontary made in a similar way. +We do not dicuss the functions body here as we already gave all the details before and +the code was volontary made in a similar way. As done before, you only have to copy the ``cgi-env`` files into your ``cgi-bin`` directory: @@ -513,10 +634,12 @@ Testing the Service using Execute Request ----------------------------------- +----------------------------------------- The simple and unreadable way -^^^^^^^^^^^^^^^^^^^^^^^^^ - -Everybody should now get his own copy of the OGR Boundary Service stored as a ZOO Services Provider called ``ogr_ws_service_provider`` and deployed in the ZOO Kernel tree, so the following Execute request can be used to test the Service: +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Everybody should now get his own copy of the OGR Boundary Service stored as a ZOO +Services Provider called ``ogr_ws_service_provider`` and deployed in the ZOO Kernel +tree, so the following Execute request can be used to test the Service: `link `__ @@ -526,5 +649,7 @@ http://localhost/cgi-bin/zoo_loader.cgi?request=Execute&service=WPS&version=1.0.0&Identifier=Boundary&DataInputs=InputPolygon=Reference@xlink:href=http%3A%2F%2Flocalhost%2Fcgi-bin%2Fmapserv%3Fmap%3D%2Fvar%2Fwww%2Fwfs.map%26SERVICE%3DWFS%26REQUEST%3DGetFeature%26VERSION%3D1.0.0%26typename%3Dregions%26SRS%3DEPSG%3A4326%26FeatureID%3Dregions.3192 -As you can see in the url above, we use an URLEncoded WFS request to the MapServer WFS server available on OSGeoLive as a ``xlink:href`` key in the DataInputs KVP value, and set the ``InputPolygon`` value to Reference. The corresponding non encoded WFS request is as follow: +As you can see in the url above, we use an URLEncoded WFS request to the MapServer +WFS server available on OSGeoLive as a ``xlink:href`` key in the DataInputs KVP value, +and set the ``InputPolygon`` value to Reference. The corresponding non encoded WFS request is as follow: :: @@ -532,5 +657,13 @@ http://localhost/cgi-bin/mapserv?map=/var/www/wfs.map&SERVICE=WFS&REQUEST=GetFeature&VERSION=1.0.0&typename=regions&SRS=EPSG:4326&featureid=regions.3192 -Please note that you can add ``lineage=true`` to the previous request if you need to get information about the input values used to run your Service. Furthermore, you may need to store the ExecuteResponse document of your ZOO Service to re-use it later. In this case you must add ``storeExecuteResponse=true`` to the previous request. Note that is an important thing as the behavior of ZOO Kernel is not exactly the same than when running without this parameter settled to true. Indeed, in such a request, ZOO Kernel will give you an ExecuteResponse document which will contain the attribute statusLocation, which inform the client where the ongoing status or the final ExecuteResponse will be located. +Please note that you can add ``lineage=true`` to the previous request if you need +to get information about the input values used to run your Service. Furthermore, +you may need to store the ExecuteResponse document of your ZOO Service to re-use +it later. In this case you must add ``storeExecuteResponse=true`` to the previous +request. Note that is an important thing as the behavior of ZOO Kernel is not +exactly the same than when running without this parameter settled to true. Indeed, +in such a request, ZOO Kernel will give you an ExecuteResponse document which will +contain the attribute statusLocation, which inform the client where the ongoing +status or the final ExecuteResponse will be located. Here is an example of what the ExecuteResponse would look like in case ``storeExecuteResponse`` was set to true in the request: @@ -541,7 +674,14 @@ :align: center -Then, according to the statusLocation, you should get the ExecuteResponse as you get before using the previous request. Note that can be really useful to provide some caching system for a client application. - -You didn't specify any ResponseForm in the previous request, it is not requested and should return a ResponseDocument per default using the application/json mimeType as you defined in you zcfg file. Nevertheless, you can tell ZOO Kernel what kind of data you want to get in result of your query adding the attribute ``mimeType=text/xml`` to your ``ResponseDocument`` parameter. Adding this parameter to the previous request will give us the result as its GML representation : +Then, according to the statusLocation, you should get the ExecuteResponse as you get +before using the previous request. Note that can be really useful to provide some +caching system for a client application. + +You didn't specify any ResponseForm in the previous request, it is not requested +and should return a ResponseDocument per default using the application/json mimeType +as you defined in you zcfg file. Nevertheless, you can tell ZOO Kernel what kind of +data you want to get in result of your query adding the attribute ``mimeType=text/xml`` +to your ``ResponseDocument`` parameter. Adding this parameter to the previous request +will give us the result as its GML representation : `link `__ @@ -551,5 +691,8 @@ http://localhost/cgi-bin/zoo_loader.cgi?request=Execute&service=WPS&version=1.0.0&Identifier=Boundary&DataInputs=InputPolygon=Reference@xlink:href=http%3A%2F%2Flocalhost%2Fcgi-bin%2Fmapserv%3Fmap%3D%2Fvar%2Fwww%2Fwfs.map%26SERVICE%3DWFS%26REQUEST%3DGetFeature%26VERSION%3D1.0.0%26typename%3Dregions%26SRS%3DEPSG%3A4326%26FeatureID%3Dregions.3192&ResponseDocument=Result@mimeType=text/xml -As defined by the WPS specifications, you can also ask for a ``RawDataOutput`` to get only the data without the full ``ResponseDocument``. To do that, you only have to replace the ``ResponseDocument`` of your request by ``RawDataOutput``, like in the following request : +As defined by the WPS specifications, you can also ask for a ``RawDataOutput`` to +get only the data without the full ``ResponseDocument``. To do that, you only have +to replace the ``ResponseDocument`` of your request by ``RawDataOutput``, like in +the following request : `link `__ @@ -559,9 +702,17 @@ http://localhost/cgi-bin/zoo_loader.cgi?request=Execute&service=WPS&version=1.0.0&Identifier=Boundary&DataInputs=InputPolygon=Reference@xlink:href=http%3A%2F%2Flocalhost%2Fcgi-bin%2Fmapserv%3Fmap%3D%2Fvar%2Fwww%2Fwfs.map%26SERVICE%3DWFS%26REQUEST%3DGetFeature%26VERSION%3D1.0.0%26typename%3Dregions%26SRS%3DEPSG%3A4326%26FeatureID%3Dregions.3192&RawDataOutput=Result@mimeType=application/json -Please note that we go back to the default mimeType to directly obtain the JSON string as we will use this kind of request to develop our client application in the next section of this workshop. - -Now, you know how to ask ZOO Kernel to run service in background, ask for ``RawDataOutput`` specifying ``mimeType`` or any specific format to be returned by the Kernel. When you ask for ``ResponseDocument``, you can also specify to the ZOO Kernel that you want the result to be stored on the server side. - -To do such a thing, you have to set the attribute ``asReference`` as true and then the resulting ExecuteResponse will contain a Reference node including the href attribute to let you access the produced file. To be able to handle this, you have to add the extension parameter in your ``DataOutputs`` node in the corresponding ZCFG file. +Please note that we go back to the default mimeType to directly obtain the JSON +string as we will use this kind of request to develop our client application in +the next section of this workshop. + +Now, you know how to ask ZOO Kernel to run service in background, ask for ``RawDataOutput`` +specifying ``mimeType`` or any specific format to be returned by the Kernel. When you +ask for ``ResponseDocument``, you can also specify to the ZOO Kernel that you want the +result to be stored on the server side. + +To do such a thing, you have to set the attribute ``asReference`` as true and then the +resulting ExecuteResponse will contain a Reference node including the href attribute +to let you access the produced file. To be able to handle this, you have to add the +extension parameter in your ``DataOutputs`` node in the corresponding ZCFG file. Here is a sample url which provide such a result: @@ -581,7 +732,11 @@ Simplification and readability of request -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - -As you can see in the simple example we used since the begining of this workshop, it is sometimes hard to write the Execute requests using the GET method as it makes really long and complexe URLs. In the next requests examples, we will thus use the POST XML requests. First , here is the XML request corresponding to the previous Execute we used: +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +As you can see in the simple example we used since the begining of this workshop, +it is sometimes hard to write the Execute requests using the GET method as it +makes really long and complexe URLs. In the next requests examples, we will +thus use the POST XML requests. First , here is the XML request corresponding +to the previous Execute we used: .. code-block:: guess @@ -607,7 +762,13 @@ -In order to let you easily run the XML requests, a simple HTML form called ``test_services.html`` is available in your ``/var/www`` directory. You can access it using the following link : http://localhost/test_services.html. - -Please open this page in your browser, simply fill the XML request content into the textarea field and click the « run using XML Request » submit button. You will get exactly the same result as when running your Service using the GET request. The screenshot above show the HTML form including the request and the ExecuteResponse document displayed in the iframe at the bottom of the page: +In order to let you easily run the XML requests, a simple HTML form called +``test_services.html`` is available in your ``/var/www`` directory. You can +access it using the following link : http://localhost/test_services.html. + +Please open this page in your browser, simply fill the XML request content into +the textarea field and click the « run using XML Request » submit button. You will +get exactly the same result as when running your Service using the GET request. The +screenshot above show the HTML form including the request and the ExecuteResponse +document displayed in the iframe at the bottom of the page: .. image:: ./images/Practical-introduction-to-ZOO-8.png @@ -616,5 +777,6 @@ :align: center -The xlink:href value is used in the simplest way to deal with such data input. Obviously, you can also use a full JSON string of the geometry, as shown in the following XML Request example : +The xlink:href value is used in the simplest way to deal with such data input. Obviously, +you can also use a full JSON string of the geometry, as shown in the following XML Request example : .. code-block:: guess @@ -643,14 +805,28 @@ -If everything went well, you should get the Boundary of the JSON geometry passed as argument, and so be sure that your Service support both GML and JSON as input data. Note that in the previous request, we added a ``mimeType`` attribute to the ``ComplexData`` node to specify that the input data is not in the default ``text/xml`` mimeType but passed as an ``application/json`` string directly. It is similar to add ``@mimeType=application/json`` as we discussed before. +If everything went well, you should get the Boundary of the JSON geometry passed as +argument, and so be sure that your Service support both GML and JSON as input data. +Note that in the previous request, we added a ``mimeType`` attribute to the +``ComplexData`` node to specify that the input data is not in the default ``text/xml`` +mimeType but passed as an ``application/json`` string directly. It is similar to add +``@mimeType=application/json`` as we discussed before. storeExecuteResponse parameter and GetStatus Service -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - -If you go in your local ``/home/user/zoows/sources/zoo-services/utils/status``, you'll find the code for a ServiceProvider which will provide the GetStatus service and the longProcess one. The last is a simple example to learn how to use the status variable from lenv section of the main configuration maps and the updateStatus function you have to call to take your status value into account. The main service provider is the GetStatus one, it is able to give you information about the current status value from a service running in background mode. - -You have to know that the ZOO Kernel will detect the presence of the GetStatus service and if it is available it will then return the link the corresponding Execute request. - -So now you will deploy the GetStatus and longProcess service on your local environment. As for each services, you shall be able to deploy the services simply by copying the cgi-env directory into your Apache ``cgi-bin`` directory. You can use the following command : +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +If you go in your local ``/home/user/zoows/sources/zoo-services/utils/status``, you'll +find the code for a ServiceProvider which will provide the GetStatus service and the +longProcess one. The last is a simple example to learn how to use the status variable +from lenv section of the main configuration maps and the updateStatus function you +have to call to take your status value into account. The main service provider is +the GetStatus one, it is able to give you information about the current status value +from a service running in background mode. + +You have to know that the ZOO Kernel will detect the presence of the GetStatus service +and if it is available it will then return the link the corresponding Execute request. + +So now you will deploy the GetStatus and longProcess service on your local environment. +As for each services, you shall be able to deploy the services simply by copying the +cgi-env directory into your Apache ``cgi-bin`` directory. You can use the following command : .. code-block:: guess @@ -658,5 +834,8 @@ sudo cp ~user/zoows/sources/zoo-services/utils/status/cgi-env/*{zcfg,zo} /usr/lib/cgi-bin -For simple Services it is the right way to deploy Service Providers. But in this specific case you'll have also to add some special parameter in the main section of you main configuration file and to copy an xsl file used to replace on the fly in the ResponseDocument the percentCompleted attribute of the ProcessStarted node returned by the GetStatus service. +For simple Services it is the right way to deploy Service Providers. But in this specific +case you'll have also to add some special parameter in the main section of you main +configuration file and to copy an xsl file used to replace on the fly in the ResponseDocument +the percentCompleted attribute of the ProcessStarted node returned by the GetStatus service. So first edit you ``main.cfg`` file to add the following lines in your main section : @@ -667,7 +846,10 @@ dataPath=/var/www/data -Here you define the path where the service is able to find the xsl file, specified in the dataPath parameter. You also tell the ZOO Kernel that you want to use the rewriteUrl we defined in the previous section. - -To finish your deployment, you'll have now to copy the xsl file in the defined dataPath directory. You can use the following command : +Here you define the path where the service is able to find the xsl file, specified in the +dataPath parameter. You also tell the ZOO Kernel that you want to use the rewriteUrl we +defined in the previous section. + +To finish your deployment, you'll have now to copy the xsl file in the defined dataPath +directory. You can use the following command : .. code-block:: guess @@ -686,5 +868,6 @@ :align: center -If you poll the statusLocation url provider in the answer you'll then be able to view the evolution of the percentCompleted attribute value growing, like you can see in the following screenshot. +If you poll the statusLocation url provider in the answer you'll then be able to view +the evolution of the percentCompleted attribute value growing, like you can see in the following screenshot. .. image:: ./images/Practical-introduction-to-ZOO-10.png @@ -697,10 +880,13 @@ Creating Services for other functions (ConvexHull and Centroid) -======================================== - -As the Boundary sample service code is available, you can now easily add ConvexHull and Centroid functions as they take exactly the same number of arguments : Only one geometry. The details for implementing and deploying the ConvexHull Service are provided bellow, and we will let you do the same thing for the Centroid one. +=============================================================== + +As the Boundary sample service code is available, you can now easily add ConvexHull and +Centroid functions as they take exactly the same number of arguments : Only one geometry. +The details for implementing and deploying the ConvexHull Service are provided bellow, +and we will let you do the same thing for the Centroid one. C Version --------- +--------- Please add first the following code to the service.c source code : @@ -743,5 +929,9 @@ -This new code is exactly the same as for the Boundary Service. The only thing we modified is the line where the `OGR_G_ConvexHull `__ function is called (rather than the OGR_G_GetBoundary you used before). It is better to not copy and paste the whole function and find a more generic way to define your new Services as the function body will be the same in every case. The following generic function is proposed to make things simpler: +This new code is exactly the same as for the Boundary Service. The only thing we modified +is the line where the `OGR_G_ConvexHull `__ +function is called (rather than the OGR_G_GetBoundary you used before). It is better to not copy +and paste the whole function and find a more generic way to define your new Services as the +function body will be the same in every case. The following generic function is proposed to make things simpler: .. code-block:: guess @@ -782,5 +972,6 @@ } -Then, a function pointer called myFunc rather than the full function name can be used. This way we can re-implement our Boundary Service this way: +Then, a function pointer called myFunc rather than the full function name can be used. +This way we can re-implement our Boundary Service this way: .. code-block:: guess @@ -790,5 +981,6 @@ } -Using this applyOne local function defined in the service.c source code, we can define other Services this way: +Using this applyOne local function defined in the service.c source code, we can define +other Services this way: .. code-block:: guess @@ -818,10 +1010,17 @@ } -To deploy your Services, you only have to copy the ``Boundary.zcfg`` metadata file from your cgi-env directory as ``ConvexHull.zcfg`` and ``Centroid.zcfg``. Then, you must rename the Service name on the first line to be able to run and test the Execute request in the same way you did before. You only have to set the Identifier value to ConvexHull or Centroid in your request depending on the Service you want to run. - -Note here that the GetCapabilities and DescribeProcess requests will return odd results as we didn't modified any metadata informations, you can edit the ``.zcfg`` files to set correct values. By the way it can be used for testing purpose, as the input and output get the same name and default/supported formats. +To deploy your Services, you only have to copy the ``Boundary.zcfg`` metadata file from +your cgi-env directory as ``ConvexHull.zcfg`` and ``Centroid.zcfg``. Then, you must +rename the Service name on the first line to be able to run and test the Execute request +in the same way you did before. You only have to set the Identifier value to ConvexHull +or Centroid in your request depending on the Service you want to run. + +Note here that the GetCapabilities and DescribeProcess requests will return odd results +as we didn't modified any metadata informations, you can edit the ``.zcfg`` files to set +correct values. By the way it can be used for testing purpose, as the input and output +get the same name and default/supported formats. Python Version ------------- +-------------- .. code-block:: guess @@ -843,7 +1042,13 @@ -Once again, you can easily copy and paste the function for Boundary and simply modify the line where the Geometry method was called. Nevertheless, as we did for the C language we will give you a simple way to get things more generic. - -First of all, the first step which consists in extracting the InputPolygon Geometry as it will be used in the same way in each Service functions, so we will first create a function which will do that for us. The same thing can also be done for filling the output value, so we will define another function to do that automaticaly. Here is the code of this two functions (extractInputs and outputResult) : +Once again, you can easily copy and paste the function for Boundary and simply modify +the line where the Geometry method was called. Nevertheless, as we did for the C language +we will give you a simple way to get things more generic. + +First of all, the first step which consists in extracting the InputPolygon Geometry as +it will be used in the same way in each Service functions, so we will first create a +function which will do that for us. The same thing can also be done for filling the +output value, so we will define another function to do that automaticaly. Here is the +code of this two functions (extractInputs and outputResult) : .. code-block:: guess @@ -902,14 +1107,21 @@ Create the Buffer Service -================ - -We can now work on the Buffer Service, which takes more arguments than the other ones. Indeed, the code is a bit different from the one used to implement the Boundary, ConvexHull and Centroid Services. - -The Buffer service also takes an input geometry, but uses a BufferDistance parameter. It will also allow you to define LitteralData block as the BufferDistance will be simple integer value. The read access to such kind of input value is made using the same function as used before. +========================= + +We can now work on the Buffer Service, which takes more arguments than the other ones. +Indeed, the code is a bit different from the one used to implement the Boundary, ConvexHull and Centroid Services. + +The Buffer service also takes an input geometry, but uses a BufferDistance parameter. +It will also allow you to define LitteralData block as the BufferDistance will be +simple integer value. The read access to such kind of input value is made using the +same function as used before. C Version --------- - -If you go back to the first Boundary Service source code, you should not find the following very complicated. Indeed, you simply have to add the access of the BufferDistance argument and modify the line whenthe `OGR_G_Buffer `__ must be called (instead of OGR_G_GetBoundary). Here is the ful lcode : +--------- + +If you go back to the first Boundary Service source code, you should not find the +following very complicated. Indeed, you simply have to add the access of the +BufferDistance argument and modify the line whenthe `OGR_G_Buffer `__ +must be called (instead of OGR_G_GetBoundary). Here is the ful lcode : .. code-block:: guess @@ -950,11 +1162,21 @@ } -The new code must be inserted in your service.c file and need to be recompiled and replace the older version of your ZOO Service Provider in the /usr/lib/cgi-bin/ directory. You must of course place the corresponding ZOO Metadata File in the same directory. - -As we explained before, ZOO Kernel is permissive in the sense that you can pass more arguments than defined in you zcfg file, so let's try using a copy of the ``Boundary.zcfg`` file renamed as ``Buffer.zcfg`` and containing the Buffer identifier. Then, please test your service using an Execute request as you did before. You will obtain the buffer result in a ResponseDocument. - -You may have noted that the above code check if a BufferDistance input was passed to the service. If not, we will use 1 as the default value, which explains why you do not have to use one more input to your previous queries. - -You can change the BufferDistance value used by your Service to compute Buffer of your geometry by adding it to the DataInputs value in your request. Note that using KVP syntaxe, each DataInputs are separated by a semicolon. +The new code must be inserted in your service.c file and need to be recompiled and +replace the older version of your ZOO Service Provider in the /usr/lib/cgi-bin/ directory. +You must of course place the corresponding ZOO Metadata File in the same directory. + +As we explained before, ZOO Kernel is permissive in the sense that you can pass more +arguments than defined in you zcfg file, so let's try using a copy of the ``Boundary.zcfg`` +file renamed as ``Buffer.zcfg`` and containing the Buffer identifier. Then, please +test your service using an Execute request as you did before. You will obtain the +buffer result in a ResponseDocument. + +You may have noted that the above code check if a BufferDistance input was passed +to the service. If not, we will use 1 as the default value, which explains why +you do not have to use one more input to your previous queries. + +You can change the BufferDistance value used by your Service to compute Buffer +of your geometry by adding it to the DataInputs value in your request. Note that +using KVP syntaxe, each DataInputs are separated by a semicolon. So, the previous request: @@ -970,5 +1192,6 @@ DataInputs=InputPolygon=Reference@xlink:href=http%3A%2F%2Flocalhost%2Fcgi-bin%2Fmapserv%3FSERVICE%3DWFS%26REQUEST%3DGetFeature%26VERSION%3D1.0.0%26typename%3Dregions%26SRS%3DEPSG%3A4326%26FeatureID%3Dregions.3192;BufferDistance=2 -Setting BufferDistance value to 2 would give you a different result, then don't pass any other parameter as we defined 1 as the default value in the source code. +Setting BufferDistance value to 2 would give you a different result, then don't +pass any other parameter as we defined 1 as the default value in the source code. Here you can find the same query in XML format to use from the http://localhost/test_services.html HTML form : @@ -1003,7 +1226,8 @@ Python Version ------------- - -As we already defined the utility functions createGeometryFromWFS and outputResult, the code is as simple as this: +-------------- + +As we already defined the utility functions createGeometryFromWFS and outputResult, +the code is as simple as this: .. code-block:: guess @@ -1021,10 +1245,15 @@ return 3 -We simply added the use of inputs["BufferDistance"]["value"] as arguments of the Geometry instance Buffer method. Once you get this code added to your ogr_ws_service_provider.py file, simply copy it in the ZOO Kernel directory (or type make install from your ZOO Service Provider root directory). Note that you also need the ``Buffer.zcfg`` file detailled in the next section. +We simply added the use of inputs["BufferDistance"]["value"] as arguments of the +Geometry instance Buffer method. Once you get this code added to your ogr_ws_service_provider.py +file, simply copy it in the ZOO Kernel directory (or type make install from your ZOO Service +Provider root directory). Note that you also need the ``Buffer.zcfg`` file detailled in the next section. The Buffer MetadataFile file ----------------------- - -You must add BufferDistance to the Service Metadata File to let clients know that this Service supports this parameter. To do this, please copy your orginal ``Boundary.zcfg`` file as ``Buffer.zcfg`` and add the following lines to the DataInputs block : +---------------------------- + +You must add BufferDistance to the Service Metadata File to let clients know that +this Service supports this parameter. To do this, please copy your orginal ``Boundary.zcfg`` +file as ``Buffer.zcfg`` and add the following lines to the DataInputs block : .. code-block:: none @@ -1046,5 +1275,7 @@ -Note that as minOccurs is set to 0 which means that the input parameter is optional and don't have to be passed. You must know that ZOO Kernel will pass the default value to the Service function for an optional parameter with a default value set. +Note that as minOccurs is set to 0 which means that the input parameter is optional +and don't have to be passed. You must know that ZOO Kernel will pass the default +value to the Service function for an optional parameter with a default value set. You can get a full copy of the ``Buffer.zcfg`` file here : Index: /trunk/docs/workshop/2010/using_zoo_from_osgeolivevm.txt =================================================================== --- /trunk/docs/workshop/2010/using_zoo_from_osgeolivevm.txt (revision 261) +++ /trunk/docs/workshop/2010/using_zoo_from_osgeolivevm.txt (revision 262) @@ -2,5 +2,5 @@ Using ZOO from an OSGeoLive virtual machine -############################################# +########################################### .. contents:: Table of Contents @@ -11,7 +11,17 @@ ZOO Kernel Installation -************************ +*********************** -As already said in introduction, an OSGeoLive virtual machine image disk has been installed on your computer, allowing you to use ZOO Kernel in a development environment directly. Using a virtual machine image disk seems to be the simplest way to use ZOO Kernel and to develop ZOO Services locally, as we can ensure that everything requested for compiling C Services and running Python ones is available and ready to use. Every ZOO related material and source code have been placed in ``/home/user/zoows`` directory. We will work inside it during this workshop. As the binary version of ZOO Kernel is already compiled and stored in ``/home/user/zoows/sources/zoo-kernel``, you only have to copy two important files inside the ``/usr/lib/cgi-bin`` directory : ``zoo_loader.cgi`` and the ``main.cfg`` in order to make ZOO Kernel available, using the following commands : +As already said in introduction, an OSGeoLive virtual machine image disk has +been installed on your computer, allowing you to use ZOO Kernel in a development +environment directly. Using a virtual machine image disk seems to be the simplest +way to use ZOO Kernel and to develop ZOO Services locally, as we can ensure that +everything requested for compiling C Services and running Python ones is available +and ready to use. Every ZOO related material and source code have been placed in +``/home/user/zoows`` directory. We will work inside it during this workshop. As +the binary version of ZOO Kernel is already compiled and stored in ``/home/user/zoows/sources/zoo-kernel``, +you only have to copy two important files inside the ``/usr/lib/cgi-bin`` +directory : ``zoo_loader.cgi`` and the ``main.cfg`` in order to make ZOO Kernel +available, using the following commands : .. code-block:: guess @@ -21,11 +31,26 @@ -Please note that we will talk about ZOO Kernel or ``zoo_loader.cgi`` script without any distinction during this workshop. +Please note that we will talk about ZOO Kernel or ``zoo_loader.cgi`` script without +any distinction during this workshop. -The ``main.cfg`` file contains metadata informations about the identification and provider but also some important settings. The file is composed of various sections, namely main, identification and provider per default. Obviously, you are free to add new sections to the file if you need them for a specific Service. Nevertheless, you have to know that the env and lenv sections name are used in a specific way. +The ``main.cfg`` file contains metadata informations about the identification and +provider but also some important settings. The file is composed of various sections, +namely main, identification and provider per default. Obviously, you are free to add +new sections to the file if you need them for a specific Service. Nevertheless, you +have to know that the env and lenv sections name are used in a specific way. -The env section lets you define environment variables that your Service requires during its runtime. For instance, if your Service requires to access to a X server running on framebuffer, then you will have to set the ``DISPLAY`` environnement variably, in this case you would add ``DISPLAY=:1`` line in your env section. +The env section lets you define environment variables that your Service requires +during its runtime. For instance, if your Service requires to access to a X server +running on framebuffer, then you will have to set the ``DISPLAY`` environnement +variably, in this case you would add ``DISPLAY=:1`` line in your env section. -As for the env section, there is the section lenv where specific informations about status informations of a running Service will be written by the ZOO Kernel or the ZOO Services. For instance, when your service failed, you can set the value for message in lenv to see it displayed in the Status node of the ExecuteResponse returned back to the client. If your service will take long time and can get informations about processing status, you can then set a value between 0 and 100 to status in lenv to represent the percentage completed of the running Service task, we will talk deeper about this later in this workshop. +As for the env section, there is the section lenv where specific informations about +status informations of a running Service will be written by the ZOO Kernel or the +ZOO Services. For instance, when your service failed, you can set the value for +message in lenv to see it displayed in the Status node of the ExecuteResponse +returned back to the client. If your service will take long time and can get +informations about processing status, you can then set a value between 0 and 100 +to status in lenv to represent the percentage completed of the running Service task, +we will talk deeper about this later in this workshop. Please take a look to your local file ``main.cfg`` file. Three important parameters are commented bellow: @@ -43,7 +68,13 @@ tmpUrl=../temp/ -You could have noticed that the tmpUrl is a relative url from ``serverAddress``, so it must be a directory. Even if ZOO Kernel can be used with the full url of the ``zoo_loader.cgi`` script, for better readability and fully functional ZOO Kernel, you have to modify the default Apache configuration in order to be able to use the http://localhost/zoo/ url directly. +You could have noticed that the tmpUrl is a relative url from ``serverAddress``, +so it must be a directory. Even if ZOO Kernel can be used with the full url of +the ``zoo_loader.cgi`` script, for better readability and fully functional ZOO Kernel, +you have to modify the default Apache configuration in order to be able to use the +http://localhost/zoo/ url directly. -First, please create a ``zoo`` directory in the existing ``/var/www`` which is used by Apache as the ``DocumentRoot``. Then, please edit the ``/etc/apache2/sites-available/default`` configuration file and add the following lines after the ``Directory`` block related to ``/var/www`` directory : +First, please create a ``zoo`` directory in the existing ``/var/www`` which is +used by Apache as the ``DocumentRoot``. Then, please edit the ``/etc/apache2/sites-available/default`` +configuration file and add the following lines after the ``Directory`` block related to ``/var/www`` directory : .. code-block:: none @@ -65,5 +96,6 @@ RewriteRule (.*) /cgi-bin/zoo_loader.cgi [L,QSA] -For this last file to be taken into account by Apache, you must activate the rewrite Apache module by copying a load file as bellow : +For this last file to be taken into account by Apache, you must activate the +rewrite Apache module by copying a load file as bellow : .. code-block:: guess @@ -84,12 +116,18 @@ -Two other softwares form the OSGeoLive environment will be used during this workshop. MapServer will first be used to provide WFS input data for the ZOO Services we are going to develop. The MapServer dataset providen by Orkney (japanese regions polygons) will be passed to our service during `section 4 `__. +Two other softwares form the OSGeoLive environment will be used during this workshop. +MapServer will first be used to provide WFS input data for the ZOO Services we are +going to develop. The MapServer dataset providen by Orkney (japanese regions polygons) +will be passed to our service during `section 4 `__. -OpenLayers library is also available on the OSGeoLive virtual machine image disk, and it will be used during `section 4 `__, for building a simple WPS client application able to query the newly developed ZOO Services. +OpenLayers library is also available on the OSGeoLive virtual machine image disk, +and it will be used during `section 4 `__, for building a simple WPS client application able to query the newly developed ZOO Services. -As we planned to use OGR C-API and Python module of the GDAL library, we will need the corresponding header files, libraries and associated files. Hopefully everything was already available per default and so ready to use on the OSGeoLive packaging. +As we planned to use OGR C-API and Python module of the GDAL library, we will need +the corresponding header files, libraries and associated files. Hopefully everything +was already available per default and so ready to use on the OSGeoLive packaging. Testing the ZOO installation with GetCapabilities -*************************************************** +************************************************* @@ -105,5 +143,7 @@ :align: center -Please note that no Process node is returned in the ProcessOfferings section, as no ZOO Service is available yet. You can also proceed to a GetCapabilities request from the command line, using the following command: +Please note that no Process node is returned in the ProcessOfferings section, as no +ZOO Service is available yet. You can also proceed to a GetCapabilities request from +the command line, using the following command: .. code-block:: none @@ -122,7 +162,8 @@ Preparing your ZOO Services Provider directory -************************************************* +********************************************** -In order to simplify the task, we will first comment the directory structure which should be used when creating a new Services Provider : +In order to simplify the task, we will first comment the directory structure which +should be used when creating a new Services Provider : - The main Services Provider directory including :