Introduction to Zend\Tag

Zend\Tag is a component suite which provides a facility to work with taggable Items. As its base, it provides two classes to work with Tags, Zend\Tag\Item and Zend\Tag\ItemList. Additionally, it comes with the interface Zend\Tag\TaggableInterface, which allows you to use any of your models as a taggable item in conjunction with Zend\Tag.

Zend\Tag\Item is a basic taggable item implementation which comes with the essential functionality required to work with the Zend\Tag suite. A taggable item always consists of a title and a relative weight (e.g. number of occurrences). It also stores parameters which are used by the different sub-components of Zend\Tag.

To group multiple items together, Zend\Tag\ItemList exists as an array iterator and provides additional functionality to calculate absolute weight values based on the given relative weights of each item in it.

Using Zend\Tag

This example illustrates how to create a list of tags and spread absolute weight values on them.

// Create the item list
$list = new Zend\Tag\ItemList();

// Assign tags to it
$list[] = new Zend\Tag\Item(array('title' => 'Code', 'weight' => 50));
$list[] = new Zend\Tag\Item(array('title' => 'Zend Framework', 'weight' => 1));
$list[] = new Zend\Tag\Item(array('title' => 'PHP', 'weight' => 5));

// Spread absolute values on the items
$list->spreadWeightValues(array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));

// Output the items with their absolute values
foreach ($list as $item) {
    printf("%s: %d\n", $item->getTitle(), $item->getParam('weightValue'));
}

This will output the three items “Code”, “Zend Framework” and “PHP” with the absolute values 10, 1 and 2.

Code: 10
Zend Framework: 1
PHP: 2