Action Context

The Action Context is an essential element of the Mojito framework that gives you access to the frameworks features from within a controller function. To use the Action Context, you create an instance of the ActionContext class, which we will call ac for short. From ac, you can call methods to execute mojit actions within either a server or client context. See the ActionContext Class for the methods available from ac.

done Method

One of the most common methods used from an instance of the ActionContext class is done, which lets you pass data from the controller to a view. You can also optionally pass meta data that contains the view name, mojit definitions, binders, assets, HTTP information, and a callback function. We’ll look at the meta object more closely in the next section.

See the done method in the Mojito API Documentation for more information about the parameters and to see the source code.

meta Object

By default, Mojito builds the metadata that is used when the method done executes and renders a template. You can, however, pass an object to override the defaults, such as the view name, mojit definitions, the assets, the view engine, HTTP information, etc.

Generally, the only time you would need to pass the meta object is in the following cases:

  • you want to render a different template than the default
  • a parent mojit is executing child mojits with the methods ac.composite.done or ac._dispatch.

In the first case, suppose you want the index function of your controller to use the template foo.hb.html instead of the default index.hb.html. You would call ac.done with the following meta object (second argument) as shown below:

...
  index: function(actionContext) {
    ac.done({ data: "Example of how to specify the templates" }, { view: { name: "foo" }});
  }
...

In the more complicated second case where metadata needs to be passed to either ac.composite.done or ac._dispatch so a parent mojit can execute children, you may need to merge the metadata of both the parent and children. Below is an example meta object containing mojit definitions and metadata about binders, assets, and the HTTP response.

{
  children:
  {
    child:
    {
      type: 'Frame',
      config: [Object],
      action: 'index',
      instanceId: 'yui_3_7_3_1_1360791588420_57'
    },
    header:
    {
      type: 'Header',
      instanceId: 'yui_3_7_3_1_1360791588420_58',
      viewId: 'yui_3_7_3_1_1360791588865_8',
      params: undefined
    },
    body:
    {
      type: 'Body',
      instanceId: 'yui_3_7_3_1_1360791588420_59',
      viewId: 'yui_3_7_3_1_1360791588865_9',
      params: undefined
    },
    footer:
    {
      type: 'Footer',
      instanceId: 'yui_3_7_3_1_1360791588420_60',
      viewId: 'yui_3_7_3_1_1360791588865_10',
      params: undefined }
    },
    assets: { bottom: { js: [] } },
    http: { code: 200, headers: { 'content-type': [Object] } },
    binders:
    {
      yui_3_7_3_1_1360791588865_8:
      {
        base: undefined,
        name: 'header-binder-index',
        action: 'index',
        config: [Object],
        type: 'Header',
        viewId: 'yui_3_7_3_1_1360791588865_8',
        instanceId: 'yui_3_7_3_1_1360791588420_58',
        children: undefined
      },
      yui_3_7_3_1_1360791588865_9:
      {
        base: undefined,
        name: 'body-binder-index',
        action: 'index',
        config: [Object],
        type: 'Body',
        viewId: 'yui_3_7_3_1_1360791588865_9',
        instanceId: 'yui_3_7_3_1_1360791588420_59',
        children: undefined
      },
      yui_3_7_3_1_1360791588865_10:
      {
        base: undefined,
        name: 'footer-binder-index',
        action: 'index',
        config: [Object],
        type: 'Footer',
        viewId: 'yui_3_7_3_1_1360791588865_10',
        instanceId: 'yui_3_7_3_1_1360791588420_60',
        children: undefined
      },
      yui_3_7_3_1_1360791588865_11:
      {
        base: undefined,
        name: 'frame-binder-index',
        action: 'index',
        config: [Object],
        type: 'Frame',
        viewId: 'yui_3_7_3_1_1360791588865_11',
        instanceId: 'yui_3_7_3_1_1360791588420_57',
        children: [Object]
      }
    }
  }
}

Example

In the example controller.server.js below, the done method sends the data object to the index template and specifies that the template foo.hb.html should be used instead of the default index.hb.html.

YUI.add('Hello', function(Y, NAME) {
  /**
  * The Hello module.
  *
  * @module Hello
  */
  /**
  * Constructor for the Controller class.
  *
  * @class Controller
  * @constructor
  */
  Y.namespace('mojito.controllers')[NAME] = {
    /**
    * Method corresponding to the 'index' action.
    *
    * @param ac {Object} The action context that
    * provides access to the Mojito API.
    */
    index: function(ac) {
      var data = { "data":"data passed to the index template" };
      ac.done(data, { view: { "name": "foo" }});
    }
  };
}, '0.0.1', {requires: []});