source: trunk/docs/services/howtos.rst @ 750

.. _services-create:

Create your own ZOO-Services
=========================

:ref:`services_index` are quite easy to create once you have installed the ZOO Kernel and have 
chosen code (in the language of your choice) to turn into a ZOO service. Here are some 
HelloWorlds in Python, PHP, Java  and JavaScript with links to their corresponding 
``.zcfg`` files.


General information
----------------------

The function of the process for each programming language take three arguments: the main
configuration, inputs and outputs.

.. note:: The service must return **3** if the process run successfully
          
.. note:: The service must return **4** if the process ended with an error

Python
------

You'll find here information needed to deploy your own Python Services Provider.

Python ZCFG requirements
************************

.. Note:: For each Service provided by your ZOO Python Services Provider, the ZCFG File 
          must be named the same as the Python module function name (also the case of
          characters is important).

The ZCFG file should contain the following :


serviceType
    Python 
serviceProvider
    The name of the Python module to use as a ZOO Service Provider. For instance, if your
    script, located in the same directory as your ZOO Kernel, was named ``my_module.py`` then
    you should use ``my_module`` (the Python module name) for the serviceProvider value in ZCFG file.

Python Data Structure used
**************************
The three parameters of the function are passed to the Python module as dictionaries.

Following you'll find an example for each parameters

Main configuration
^^^^^^^^^^^^^^^^^^^^^
Main configuration contains several informations, some of them are really useful to develop your service.
Following an example ::

  {
  'main': {'lang': 'en-UK',
           'language': 'en-US',
           'encoding': 'utf-8',
           'dataPath': '/var/www/tmp',
           'tmpPath': '/var/www/tmp',
           'version': '1.0.0',
           'mapserverAddress': 'http://localhost/cgi-bin/mapserv',
           'isSoap': 'false',
           'tmpUrl': 'http://localhost/tmp/',
           'serverAddress': 'http://localhost/zoo'
          },
  'identification': {'keywords': 'WPS,GIS',
                     'abstract': 'WPS services for testing ZOO',
                     'fees': 'None',
                     'accessConstraints': 'none',
                     'title': 'testing services'
                    },
  'lenv': {'status': '0',
           'soap': 'false',
           'cwd': '/usr/lib/cgi-bin',
           'sid': '24709'
          },
  'env': {'DISPLAY': 'localhost:0'},
  'provider': {'addressCountry': 'it',
               'positionName': 'Developer',
               'providerName': 'Name of provider',
               'addressAdministrativeArea': 'False',
               'phoneVoice': 'False',
               'addressCity': 'City',
               'providerSite': 'http://www.your.site',
               'addressPostalCode': '38122',
               'role': 'Developer',
               'addressDeliveryPoint': 'False',
               'phoneFacsimile': 'False', 
               'addressElectronicMailAddress': 'your@email.com',
               'individualName': 'Your Name'
              }
  }

Inputs
^^^^^^^^^^^^
The inputs are somethings like this ::

  {
  'variable_name': {'minOccurs': '1',
                    'DataType': 'string',
                    'value': 'this_is_the_value',
                    'maxOccurs': '1',
                    'inRequest': 'true'
                   }
  }

The access to the value you have to require for the ``value`` parameter, something like this ::

  yourVariable = inputs['variable_name']['value']

Outputs
^^^^^^^^^^^^^
The outputs data as a structure really similar to the inputs one ::

  {
  'result': {'DataType': 'string',
             'inRequest': 'true',
            }
  }

There is no ``'value'`` parameter before you assign it ::

  inputs['result']['value'] = yourOutputDataVariable

The return statement has to be an integer: corresponding to the service status code.

To add a message for the wrong result you can add the massage to ``conf["lenv"]["message"]``,
for example:

.. code-block:: python

  conf["lenv"]["message"] = 'Your module return an error'

Sample ZOO Python Services Provider
***********************************

The following code represents a simple ZOO Python Services Provider which provides only one 
Service, the HelloPy one.

.. code-block:: python

  import zoo
  import sys
  def HelloPy(conf,inputs,outputs):
     outputs["Result"]["value"]="Hello "+inputs["a"]["value"]+" from Python World !"
     return zoo.SERVICE_SUCCEEDED

PHP
---

ZOO-API
*******

The ZOO-API for the PHP language is automatically available from your
service code. Tthe following functions are defined in the ZOO-API:

int zoo_SERVICE_SUCCEEDED()
    return the value of SERVICE_SUCCEEDED
int zoo_SERVICE_FAILED()
    return the value of SERVICE_FAILED
string zoo_Translate(string a)
    return the translated string (using the "zoo-service" `textdomain
    <http://www.gnu.org/software/libc/manual/html_node/Locating-gettext-catalog.html#index-textdomain>`__)

void zoo_UpdateStatus(Array conf,string message,int pourcent)
    update the status of the running service

PHP ZCFG requirements
**********************************

The ZCFG file should contain the following :

serviceType
    PHP 
serviceProvider
    The name of the php script (ie. service.php) to use as a ZOO Service Provider.

PHP Data Structure used
********************************

The three parameters are passed to the PHP function as 
`Arrays <php.net/manual/language.types.array.php>`__.

Sample ZOO PHP Services Provider
******************************************

.. code-block:: php

  <?
  function HelloPHP(&$main_conf,&$inputs,&$outputs){
     $tmp="Hello ".$inputs[S][value]." from PHP world !";
     $outputs["Result"]["value"]=zoo_Translate($tmp);
     return zoo_SERVICE_SUCCEEDED();
  }
  ?>

Java
----

Specifically for the Java support, you may add the following two
sections to your ``main.cfg`` file:

:[javaxx]:
   This section is used to pass -XX:* parameters to the JVM  created by the
   ZOO-Kernel to handle your ZOO-Service (see `ref. 1
   <http://www.oracle.com/technetwork/java/javase/tech/vmoptions-jsp-140102.html#BehavioralOptions>`__
   or `ref. 2
   <http://www.oracle.com/technetwork/java/javase/tech/vmoptions-jsp-140102.html#PerformanceTuning>`__
   for sample available). 
   For each map ``a = b`` available in the ``[javaxx]`` section, the
   option ``-XX:a=b`` will be passed to the JVM. In case of a map ``a =
   minus`` (respectively ``a=plus``) then the option ``-XX:-a``
   (respectivelly ``-XX:+a``) will be passed.
:[javax]:
   The section is used to pass -X* options to the JVM (see
   `ref. <http://docs.oracle.com/cd/E22289_01/html/821-1274/configuring-the-default-jvm-and-java-arguments.html>`__). For
   each map ``a = b`` available in the ``[javax]`` section, the option
   ``-Xab`` will be passed to the JVM (ie. set ``mx=2G`` to pass
   ``-Xmx2G``).

ZOO-API
*******

Before you build your first ZOO-Service implemented in Java, it is
recommended that you first build the ZOO class of the Java ZOO-API.

.. Note:: You should build ZOO-Kernel prior to follow this instructions.

To build the ZOO.class of the ZOO-API for Java, use the following
command:

.. code-block:: guess

  cd zoo-api/java
  make
  cp ZOO.class libZOO.so /usr/lib/cgi-bin

.. Note:: running the previous commands will require that both
          ``javac`` and ``javah`` are in your PATH.

Java ZCFG requirements
**********************************

.. Note:: For each Service provided by your ZOO Java Services Provider
          (your corresponding Java class), the ZCFG File should have
          the name of the Java public method corresponding to the
          service (case-sensitive).

The ZCFG file should contain the following :

serviceType
    Java 
serviceProvider
    The name of the Java class to use as a ZOO Service Provider. For instance, if your
    java class, located in the same directory as your ZOO-Kernel, was
    named ``HelloJava.class`` then you should use ``HelloJava``.

Java Data Structure used
********************************

The three parameters are passed to the Java function as 
`java.util.HashMap <http://docs.oracle.com/javase/8/docs/api/java/util/HashMap.html>`__.

Sample ZOO Java Services Provider
******************************************

.. code-block:: java

  import java.util.*;
  public class HelloJava {
    public static int HelloWorldJava(HashMap conf,HashMap inputs, HashMap outputs) {
       HashMap hm1 = new HashMap();
       hm1.put("dataType","string");
       HashMap tmp=(HashMap)(inputs.get("S"));
       java.lang.String v=tmp.get("value").toString();
       hm1.put("value","Hello "+v+" from JAVA WOrld !");
       outputs.put("Result",hm1);
       System.err.println("Hello from JAVA WOrld !");
       return ZOO.SERVICE_SUCCEEDED;
    }
  }

Javascript
----------

ZOO API
*********

If you need to use :ref:`ZOO API <api>` in your service, you have first to copy ``zoo-api.js``
and ``zoo-proj4js.js`` where your services are located (for example in Unix system probably in
``/usr/lib/cgi-bin/``

Javascript ZCFG requirements
**********************************

.. Note:: For each Service provided by your ZOO Javascript Services Provider, the ZCFG File 
          must be named the same as the Javascript function name (also the case of
          characters is important).

The ZCFG file should contain the following :

serviceType
    JS 
serviceProvider
    The name of the JavaScript file to use as a ZOO Service Provider. For instance, if your
    script, located in the same directory as your ZOO Kernel, was named ``my_module.js`` then
    you should use ``my_module.js``.


Javascript Data Structure used
********************************

The three parameters of the function are passed to the JavaScript function as Object.

Sample ZOO Javascript Services Provider
******************************************

.. code-block:: javascript

  function hellojs(conf,inputs,outputs){
     outputs=new Array();
     outputs={};
     outputs["result"]["value"]="Hello "+inputs["S"]["value"]+" from JS World !";
     return Array(3,outputs);
  }