4.1.8.2. Necessary files

The WebApp structure consists of two necessary files, including web.xml, and gadget.xml.

In the web.xml file, there are 2 requirements:

The org.exoplatform.portal.application.ResourceRequestFilter filter: handle requests to map into GateIn.
The org.gatein.wci.api.GateInServlet servlet: help to register this WebApp to GateIn.


<web-app>

  <display-name>eXoGadgets</display-name>

  <filter>

    <filter-name>ResourceRequestFilter</filter-name>

    <filter-class>org.exoplatform.portal.application.ResourceRequestFilter</filter-class>

  </filter>



  <filter-mapping>

    <filter-name>ResourceRequestFilter</filter-name>

    <url-pattern>/*</url-pattern>

  </filter-mapping>



  <servlet>

    <servlet-name>GateInServlet</servlet-name>

    <servlet-class>org.gatein.wci.api.GateInServlet</servlet-class>

    <load-on-startup>0</load-on-startup>

  </servlet>



  <servlet-mapping>

    <servlet-name>GateInServlet</servlet-name>

    <url-pattern>/gateinservlet</url-pattern>

  </servlet-mapping>



</web-app>

The gadget.xml file is used to locate the configuration of gadgets that you want to add to the Application Registry.


 <gadgets

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

    xsi:schemaLocation="http://www.gatein.org/xml/ns/gatein_objects_1_0 http://www.gatein.org/xml/ns/gadgets_1_0"

    xmlns="http://www.gatein.org/xml/ns/gadgets_1_0">



    <gadget name="To-do">

        <path>/gadgets/Todo/Todo.xml</path>

    </gadget>



    <gadget name="Calendar">

        <path>/gadgets/Calendar/Calendar.xml</path>

    </gadget>



    <gadget name="Calculator">

        <path>/gadgets/Calculator/Calculator.xml</path>

    </gadget>



    <gadget name="rssAggregator">

        <path>/gadgets/rssAggregator/rssAggregator.xml</path>

    </gadget>



  <gadget name="Currency">

    <url>http://www.donalobrien.net/apps/google/currency.xml</url>

  </gadget>



  <gadget name="ServicesManagement">

    <path>/gadgets/ServicesManagement/ServicesManagement.xml</path>

  </gadget>

</gadgets>

This file has 3 important tags:

<gadget>: every gadget will be configured in the <gadget> tag which has a "name" attribute to indicate the gadget name that Application Registry manages. The <gadget> tag can contain a child tag, either <path>, or <url>.
<path>: this tag is the child of the <gadget> tag. It indicates the path to the gadget and helps the Gadget service find exactly where the gadget source and resources are located. It is known as the local path of the server.
<url>: if the gadget source is located from the external server, the <url> tag should be configured to indicate the URL of the gadget.