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<!ENTITY % BOOK_ENTITIES SYSTEM "cloudstack.ent">
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   <chapter id="third-party-ui-plugin">
      <!-- CLOUDSTACK-883 -->
      <title>Third-Party UI Plugin Framework</title>
      <para>Using the new third-party plugin framework, you can write and install extensions to
        &PRODUCT;. The installed and enabled plugins will appear in the UI alongside the
        other features.
        The code for the plugin is simply placed in a special directory
        within &PRODUCT;’s installed code at any time after &PRODUCT; installation. The new plugin
        appears only when it is enabled by the cloud administrator.</para>
     <mediaobject>
       <imageobject>
         <imagedata fileref="./images/plugin_intro.jpg"/>
       </imageobject>
       <textobject>
         <phrase>plugin_intro.jpg: New plugin button in product navbar</phrase>
       </textobject>
     </mediaobject>
     <para>The left navigation bar of the &PRODUCT; UI has a new Plugins button to help you work with UI plugins.</para>
      <section id="plugin-howto-overview">
        <title>How to Write a Plugin: Overview</title>
        <para>The basic procedure for writing a plugin is:</para>
        <orderedlist>
          <listitem>
            <para>Write the code and create the other files needed. You will need the plugin code
              itself (in Javascript), a thumbnail image, the plugin listing, and a CSS file.</para>
            <mediaobject>
              <imageobject>
                <imagedata fileref="./images/plugin1.jpg"/>
              </imageobject>
              <textobject>
                <phrase>plugin1.jpg: Write the plugin code</phrase>
              </textobject>
            </mediaobject>
            <para>All UI plugins have the following set of files:</para>
            <programlisting>+-- cloudstack/
  +-- ui/
    +-- plugins/
      +-- csMyFirstPlugin/
        +-- config.js            --> Plugin metadata (title, author, vendor URL, etc.)
        +-- icon.png             --> Icon, shown on side nav bar and plugin listing
                                     (should be square, and ~50x50px)
        +-- csMyFirstPlugin.css  --> CSS file, loaded automatically when plugin loads
        +-- csMyFirstPlugin.js   --> Main JS file, containing plugin code              
            </programlisting>
            <para>The same files must also be present at /tomcat/webapps/client/plugins.</para>
          </listitem>
          <listitem>
            <para>The &PRODUCT; administrator adds the folder containing your plugin code under the
              &PRODUCT; PLUGINS folder.</para>
            <mediaobject>
              <imageobject>
                <imagedata fileref="./images/plugin2.jpg"/>
              </imageobject>
              <textobject>
                <phrase>plugin2.jpg: The plugin code is placed in the PLUGINS folder</phrase>
              </textobject>
            </mediaobject>
          </listitem>
          <listitem>
            <para>The administrator also adds the name of your plugin to the plugin.js file in the
              PLUGINS folder.</para>
            <mediaobject>
              <imageobject>
                <imagedata fileref="./images/plugin3.jpg"/>
              </imageobject>
              <textobject>
                <phrase>plugin3.jpg: The plugin name is added to plugin.js in the PLUGINS
                  folder</phrase>
              </textobject>
            </mediaobject>
          </listitem>
          <listitem>
            <para>The next time the user refreshes the UI in the browser, your plugin will appear in
              the left navigation bar.</para>
            <mediaobject>
              <imageobject>
                <imagedata fileref="./images/plugin4.jpg"/>
              </imageobject>
              <textobject>
                <phrase>plugin4.jpg: The plugin appears in the UI</phrase>
              </textobject>
            </mediaobject>
          </listitem>
        </orderedlist>
      </section>
      <section id="plugin-howto-details">
        <title>How to Write a Plugin: Implementation Details</title>
        <para>This section requires an understanding of JavaScript and the &PRODUCT; API. You don't
          need knowledge of specific frameworks for this tutorial (jQuery, etc.), since the
          &PRODUCT; UI handles the front-end rendering for you.</para>
        <para>There is much more to the &PRODUCT; UI framework than can be described here. The UI is
          very flexible to handle many use cases, so there are countless options and variations. The
          best reference right now is to read the existing code for the main UI, which is in the /ui
          folder. Plugins are written in a very similar way to the main UI.</para>
        <orderedlist>
          <listitem>
            <para><emphasis role="bold">Create the directory to hold your plugin.</emphasis></para>
            <para>All plugins are composed of set of required files in the directory
              /ui/plugins/pluginID, where pluginID is a short name for your plugin. It's recommended
              that you prefix your folder name (for example, bfMyPlugin) to avoid naming conflicts
              with other people's plugins.</para>
            <para>In this example, the plugin is named csMyFirstPlugin.</para>
            <programlisting>$ cd cloudstack/ui/plugins
$ mkdir csMyFirstPlugin
$ ls -l

total 8
drwxr-xr-x  2 bgregory  staff   68 Feb 11 14:44 csMyFirstPlugin
-rw-r--r--  1 bgregory  staff  101 Feb 11 14:26 plugins.js
          </programlisting>
          </listitem>
          <listitem>
            <para><emphasis role="bold">Change to your new plugin directory.</emphasis></para>
            <programlisting>$ cd csMyFirstPlugin
            </programlisting>
          </listitem>
          <listitem>
            <para><emphasis role="bold">Set up the listing.</emphasis></para>
            <para>Add the file config.js, using your favorite editor.</para>
            <programlisting>$ vi config.js</programlisting>
            <para>Add the following content to config.js. This information will be displayed on the
              plugin listing page in the UI:</para>
            <programlisting>(function (cloudStack) {
  cloudStack.plugins.csMyFirstPlugin.config = {
    title: 'My first plugin',
    desc: 'Tutorial plugin',
    externalLink: 'http://www.cloudstack.org/',
    authorName: 'Test Plugin Developer',
    authorEmail: 'plugin.developer@example.com'
  };
}(cloudStack));            
          </programlisting>
          </listitem>
          <listitem>
            <para><emphasis role="bold">Add a new main section.</emphasis></para>
            <para>Add the file csMyFirstPlugin.js, using your favorite editor.</para>
            <programlisting>$ vi csMyFirstPlugin.js</programlisting>
            <para>Add the following content to csMyFirstPlugin.js:</para>
            <programlisting>(function (cloudStack) {
  cloudStack.plugins.csMyFirstPlugin = function(plugin) {
    plugin.ui.addSection({
      id: 'csMyFirstPlugin',
      title: 'My Plugin',
      preFilter: function(args) {
        return isAdmin();
      },
      show: function() {
        return $('&lt;div&gt;').html('Content will go here');
      }
    });
  };
}(cloudStack));            
          </programlisting>
          </listitem>
          <listitem>
            <para><emphasis role="bold">Register the plugin.</emphasis></para>
            <para>You now have the minimal content needed to run the plugin, so you can activate the
              plugin in the UI by adding it to plugins.js. First, edit the file:</para>
            <programlisting>$ cd cloudstack/ui/plugins
$ vi plugins.js              
            </programlisting>
            <para>Now add the following to plugins.js:</para>
            <programlisting>(function($, cloudStack) {
  cloudStack.plugins = [
    'csMyFirstPlugin'
  ];
}(jQuery, cloudStack));            
          </programlisting>
          </listitem>
          <listitem>
            <para><emphasis role="bold">Check the plugin in the UI.</emphasis></para>
            <para>First, copy all the plugin code that you have created so far to
              /tomcat/webapps/client/plugins. Then refresh the browser and click Plugins in the side
              navigation bar. You should see your new plugin.</para>
          </listitem>
          <listitem>
            <para><emphasis role="bold">Make the plugin do something.</emphasis></para>
            <para>Right now, you just have placeholder content in the new plugin. It's time to add
              real code. In this example, you will write a basic list view, which renders data from
              an API call. You will list all virtual machines owned by the logged-in user. To do
              this, replace the 'show' function in the plugin code with a 'listView' block,
              containing the required syntax for a list view. To get the data, use the
              listVirtualMachines API call. Without any parameters, it will return VMs only for your
              active user. Use the provided 'apiCall' helper method to handle the server call. Of
              course, you are free to use any other method for making the AJAX call (for example,
              jQuery's $.ajax method).</para>
            <para>First, open your plugin's JavaScript source file in your favorite editor:</para>
            <programlisting>$ cd csMyFirstPlugin
$ vi csMyFirstPlugin.js              
            </programlisting>
            <para>Add the following code in csMyFirstPlugin.js:</para>
            <programlisting>(function (cloudStack) {
  cloudStack.plugins.csMyFirstPlugin = function(plugin) {
    plugin.ui.addSection({
      id: 'csMyFirstPlugin',
      title: 'My Plugin',
      preFilter: function(args) {
        return isAdmin();
      },

      // Render page as a list view
      listView: {
        id: 'testPluginInstances',
        fields: {
          name: { label: 'label.name' },
          instancename: { label: 'label.internal.name' },
          displayname: { label: 'label.display.name' },
          zonename: { label: 'label.zone.name' }
        },
        dataProvider: function(args) {
          // API calls go here, to retrive the data asynchronously
          //
          // On successful retrieval, call
          // args.response.success({ data: [data array] });
          plugin.ui.apiCall('listVirtualMachines', {
            success: function(json) {
              var vms = json.listvirtualmachinesresponse.virtualmachine;

              args.response.success({ data: vms });
            },
            error: function(errorMessage) {
              args.response.error(errorMessage)
            }
          });
        }
      }
    });
  };
}(cloudStack));            
          </programlisting>
          </listitem>
          <listitem>
            <para><emphasis role="bold">Test the plugin.</emphasis></para>
            <para>First, copy all the plugin code that you have created so far to
              /tomcat/webapps/client/plugins. Then refresh the browser. You can see that your
              placeholder content was replaced with a list table, containing 4 columns of virtual
              machine data.</para>
          </listitem>
          <listitem>
            <para><emphasis role="bold">Add an action button.</emphasis></para>
            <para>Let's add an action button to the list view, which will reboot the VM. To do this,
              add an actions block under listView. After specifying the correct format, the actions
              will appear automatically to the right of each row of data.</para>
            <programlisting>$ vi csMyFirstPlugin.js              
            </programlisting>
            <para>Now add the following new code in csMyFirstPlugin.js. (The dots ... show where we
              have omitted some existing code for the sake of space. Don't actually cut and paste
              that part):</para>
            <programlisting>...
      listView: {
        id: 'testPluginInstances',
        ...

        actions: {
          // The key/ID you specify here will determine what icon is
          // shown in the UI for this action,
          // and will be added as a CSS class to the action's element
          // (i.e., '.action.restart')
          //
          // -- here, 'restart' is a predefined name in &PRODUCT; that will
          // automatically show a 'reboot' arrow as an icon;
          // this can be changed in csMyFirstPlugin.css
          restart: {
            label: 'Restart VM',
            messages: {
              confirm: function() { return 'Are you sure you want to restart this VM?' },
              notification: function() { return 'Rebooted VM' }
            },
            action: function(args) {
              // Get the instance object of the selected row from context
              //
              // -- all currently loaded state is stored in 'context' as objects,
              //    such as the selected list view row, 
              //    the selected section, and active user
              //
              // -- for list view actions, the object's key will be the same as
              //    listView.id, specified above;
              //    always make sure you specify an 'id' for the listView,
              //     or else it will be 'undefined!'
              var instance = args.context.testPluginInstances[0];

              plugin.ui.apiCall('rebootVirtualMachine', {
                // These will be appended to the API request
                //
                // i.e., rebootVirtualMachine&amp;id=...
                data: {
                  id: instance.id
                },
                success: function(json) {
                  args.response.success({
                    // This is an async job, so success here only indicates
                    // that the job was initiated.
                    //
                    // To pass the job ID to the notification UI
                    // (for checking to see when action is completed),
                    // '_custom: { jobID: ... }' needs to always be passed on success,
                    // in the same format as below
                    _custom: { jobId: json.rebootvirtualmachineresponse.jobid }
                  });
                },
                
                
                error: function(errorMessage) {
                  args.response.error(errorMessage); // Cancel action, show error message returned
                }
              });
            },

            // Because rebootVirtualMachine is an async job, we need to add
            // a poll function, which will perodically check
            // the management server to see if the job is ready
            // (via pollAsyncJobResult API call)
            //
            // The plugin API provides a helper function, 'plugin.ui.pollAsyncJob',
            /  which will work for most jobs
            // in &PRODUCT;
            notification: {
              poll: plugin.ui.pollAsyncJob
            }
          }
        },

        dataProvider: function(args) {
          ...
...             
           </programlisting>
          </listitem>
          <listitem>
            <para><emphasis role="bold">Add the thumbnail icon.</emphasis></para>
            <para>Create an icon file; it should be square, about 50x50 pixels, and named icon.png.
              Copy it into the same directory with your plugin code:
              cloudstack/ui/plugins/csMyFirstPlugin/icon.png.</para>
          </listitem>
          <listitem>
            <para><emphasis role="bold">Add the stylesheet.</emphasis></para>
            <para>Create a CSS file, with the same name as your .js file. Copy it into the same
              directory with your plugin code:
              cloudstack/ui/plugins/csMyFirstPlugin/csMyFirstPlugin.css.</para>
          </listitem>
        </orderedlist>
      </section>
    </chapter>
