Creating User Menu Portlet

In this section, we will develop our first concrete portlet - the user menu portlet which displays a list of menu items that are only available to authenticated users. The menu contains four items:

  • Approve Comments: a hyperlink that leads to a list of comments pending approval;
  • Create New Post: a hyperlink that leads to the post creation page;
  • Manage Posts: a hyperlink that leads to the post management page;
  • Logout: a link button that would log out the current user.

1. Creating UserMenu Class

We create the UserMenu class to represent the logic part of the user menu portlet. The class is saved in the file /wwwroot/blog/protected/components/UserMenu.php which has the following content:

<?php
class UserMenu extends Portlet
{
    public function init()
    {
        $this->title=CHtml::encode(Yii::app()->user->name);
        parent::init();
    }
 
    protected function renderContent()
    {
        $this->render('userMenu');
    }
}

The UserMenu class extends from the Portlet class that we created previously. It overrides both the init() method and the renderContent() method of Portlet. The former sets the portlet title to be the name of the current user; the latter generates the portlet body content by rendering a view named userMenu.

Tip: Notice that we do not explicitly include the class file for Portlet even though we reference it in the code. This is due to the reason we explained in the previous section.

2. Creating userMenu View

Next, we create the userMenu view which is saved in the file /wwwroot/blog/protected/components/views/userMenu.php:

<ul>
<li><?php echo CHtml::link('Approve Comments', array('comment/list'))
    . ' (' . Comment::model()->pendingCommentCount . ')'; ?></li>
<li><?php echo CHtml::link('Create New Post',array('post/create')); ?></li>
<li><?php echo CHtml::link('Manage Posts',array('post/admin')); ?></li>
<li><?php echo CHtml::linkButton('Logout',array(
    'submit'=>'',
    'params'=>array('command'=>'logout'),
)); ?></li>
</ul>

Info: By default, view files for a widget should be placed under the views sub-directory of the directory containing the widget class file. The file name must be the same as the view name.

In the view, we call CHtml::link to create the needed hyperlinks; we also call CHtml::linkButton to create a link button which works like a normal push button. When the button is clicked, it submits an implicit form to the current page with the parameter command whose value is logout.

In order to respond to the clicking of the logout hyperlink, we need to modify the init() method of UserMenu as follows:

public function init()
{
    if(isset($_POST['command']) && $_POST['command']==='logout')
    {
        Yii::app()->user->logout();
        $this->controller->redirect(Yii::app()->homeUrl);
    }
 
    $this->title=CHtml::encode(Yii::app()->user->name);
    parent::init();
}

In the init() method, we check if there is a command POST variable whose value is logout. If so, we log out the current user and redirect the user browser to the application's home page. Note that the redirect() method will implicitly terminate the execution of the current application.

3. Using UserMenu Portlet

It is time for us to make use of our newly completed UserMenu portlet. We modify the layout view file /wwwroot/blog/protected/views/layouts/main.php as follows:

......
 
<div id="sidebar">
 
<?php $this->widget('UserMenu',array('visible'=>!Yii::app()->user->isGuest)); ?>
 
</div>
 
......

In the above, we call the widget() method to generate and execute an instance of the UserMenu class. Because the portlet should only be displayed to authenticated users, we toggle its visible property according to the isGuest property of the current user.

4. Testing UserMenu Portlet

Let's test what we have so far.

  1. Open a browser window and enter the URL http://www.example.com/blog/index.php. Verify that there is nothing displayed in the side bar section of the page.
  2. Click on the Login hyperlink and fill out the login form to login. If successful, verify that the UserMenu portlet appears in the side bar and the portlet has the username as its title.
  3. Click on the 'Logout' hyperlink in the UserMenu portlet. Verify that the logout action is successful and the UserMenu portlet disappears.

5. Summary

What we have created is a portlet that is highly reusable. We can easily reuse it in a different project with little or no modification. Moreover, the design of this portlet follows closely the philosophy that logic and presentation should be separated. While we did not point this out in the previous sections, such practice is used nearly everywhere in a typical Yii application.

$Id: portlet.menu.txt 671 2009-02-13 21:55:24Z qiang.xue $

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