Zend\Tag

Creating tag clouds with Zend\Tag\Cloud

Zend\Tag\Cloud is the rendering part of Zend\Tag. By default it comes with a set of HTML decorators, which allow you to create tag clouds for a website, but also supplies you with two abstract classes to create your own decorators, to create tag clouds in PDF documents for example.

You can instantiate and configure Zend\Tag\Cloud either programatically or completely via an array or an instance of Zend\Config\Config. The available options are:

  • cloudDecorator: defines the decorator for the cloud. Can either be the name of the class which should be loaded by the pluginloader, an instance of Zend\Tag\Cloud\Decorator\Cloud or an array containing the string ‘decorator’ and optionally an array ‘options’, which will be passed to the decorators constructor.
  • tagDecorator: defines the decorator for individual tags. This can either be the name of the class which should be loaded by the pluginloader, an instance of Zend\Tag\Cloud\Decorator\Tag or an array containing the string ‘decorator’ and optionally an array ‘options’, which will be passed to the decorators constructor.
  • pluginDecoratorManager: a different plugin manager to use. Must be an instance of Zend\ServiceManager\AbstractPluginManager.
  • itemList: a different item list to use. Must be an instance of Zend\Tag\ItemList.
  • tags: a list of tags to assign to the cloud. Each tag must either implement Zend\Tag\TaggableInterface or be an array which can be used to instantiate Zend\Tag\Item.

Using Zend\Tag\Cloud

This example illustrates a basic example of how to create a tag cloud, add multiple tags to it and finally render it.

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// Create the cloud and assign static tags to it
$cloud = new Zend\Tag\Cloud(array(
    'tags' => array(
        array('title' => 'Code', 'weight' => 50,
              'params' => array('url' => '/tag/code')),
        array('title' => 'Zend Framework', 'weight' => 1,
              'params' => array('url' => '/tag/zend-framework')),
        array('title' => 'PHP', 'weight' => 5,
              'params' => array('url' => '/tag/php')),
    )
));

// Render the cloud
echo $cloud;

This will output the tag cloud with the three tags, spread with the default font-sizes.

The following example shows how create a tag cloud from a Zend\Config\Config object.

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# An example tags.ini file
tags.1.title = "Code"
tags.1.weight = 50
tags.1.params.url = "/tag/code"
tags.2.title = "Zend Framework"
tags.2.weight = 1
tags.2.params.url = "/tag/zend-framework"
tags.3.title = "PHP"
tags.3.weight = 2
tags.3.params.url = "/tag/php"
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// Create the cloud from a Zend\Config\Config object
$config = Zend\Config\Factory::fromFile('tags.ini');
$cloud = new Zend\Tag\Cloud($config);

// Render the cloud
echo $cloud;

Decorators

Zend\Tag\Cloud requires two types of decorators to be able to render a tag cloud. This includes a decorator which renders the single tags as well as a decorator which renders the surrounding cloud. Zend\Tag\Cloud ships a default decorator set for formatting a tag cloud in HTML. This set will by default create a tag cloud as ul/li-list, spread with different font-sizes according to the weight values of the tags assigned to them.

HTML Tag decorator

The HTML tag decorator will by default render every tag in an anchor element, surounded by a li element. The anchor itself is fixed and cannot be changed, but the surrounding element(s) can.

Note

URL parameter

As the HTML tag decorator always surounds the tag title with an anchor, you should define an URL parameter for every tag used in it.

The tag decorator can either spread different font-sizes over the anchors or a defined list of classnames. When setting options for one of those possibilities, the corespondening one will automatically be enabled. The following configuration options are available:

  • fontSizeUnit: defines the font-size unit used for all font-sizes. The possible values are: em, ex, px, in, cm, mm, pt, pc and %. Default value is px.
  • minFontSize: the minimum font-size distributed through the tags (must be an integer). Default value is 10.
  • maxFontSize: the maximum font-size distributed through the tags (must be an integer). Default value is 20.
  • classList: an arry of classes distributed through the tags.
  • htmlTags: an array of HTML tags surrounding the anchor. Each element can either be a string, which is used as element type then, or an array containing an attribute list for the element, defined as key/value pair. In this case, the array key is used as element type.

The following example shows how to create a tag cloud with a customized HTML tag decorator.

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$cloud = new Zend\Tag\Cloud(array(
    'tagDecorator' => array(
        'decorator' => 'htmltag',
        'options' => array(
            'minFontSize' => '20',
            'maxFontSize' => '50',
            'htmlTags' => array(
                'li' => array('class' => 'my_custom_class')
            )
        )
    ),
    'tags' => array(
       array('title' => 'Code', 'weight' => 50,
             'params' => array('url' => '/tag/code')),
       array('title' => 'Zend Framework', 'weight' => 1,
             'params' => array('url' => '/tag/zend-framework')),
       array('title' => 'PHP', 'weight' => 5,
             'params' => array('url' => '/tag/php')),
   )
));

// Render the cloud
echo $cloud;

HTML Cloud decorator

The HTML cloud decorator will suround the HTML tags with an ul-element by default and add no separation. Like in the tag decorator, you can define multiple surrounding HTML tags and additionally define a separator. The available options are:

  • separator: defines the separator which is placed between all tags.
  • htmlTags: an array of HTML tags surrounding all tags. Each element can either be a string, which is used as element type then, or an array containing an attribute list for the element, defined as key/value pair. In this case, the array key is used as element type.
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