What is the use of zend tag component in zend framework?

Question

I want to know about Zend Tag Component.

What is it? How to use this in my project?

Suppose I have following three tables: posts - id,name tags - id,name posts_tags - id,post_id,tag_id

How can I use this component to create a tag cloud? What is weight?

I have checked these:
http://framework.zend.com/manual/current/en/modules/zend.tag.introduction.html

http://framework.zend.com/manual/current/en/modules/zend.tag.cloud.html

Answer 1

As an example, you have two tags: Tag A occuring 1000 times, Tag B occuring only once, and Tag C occuring 50 times. The first idea might be have the number of occurences to be the font size. Now that ain't very helpful as we'd have Tag A at font size 1000 , and Tag B at font size 1 . Instead you probably want something like:

• The tag occuring most should have font-size 25
• The tag occuring least should have font-size 10
• All other tags should be spread evenly in between in font-size steps of 2

This is where this module comes into place. The basic problem this module tries to solve is the mapping of how often a tag occurs to how large you want it to be displayed in relation to other tags . Or to be put into a function: calculateBoundedFontSize(count($tag)) .

In Zend\\Tag\\ this is handled by weights (how much a tag occurs), and values (the font size value in relation to a tag's weight):

• First we create a list of tags, giving each a weight (eg the number of occurances).
• Second we tell the module to map an array of allowed font-sizes to the items, in relation to the number of occurances.

The second is done by this line in the documenation:

$list->spreadWeightValues(array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));

Which basically tells the module to give the tag occoring most a font-size of 10 , the one occoring least a font size of 1 . Everything in between is spread occordingly. To come back to the initial example, Tag A would get a font size of 10 , Tag B a font-size of 1 , and Tag C a font-size of 2 .

The reason the documentation isn't particularry talking about count and font size is for abstraction. Instead of taking the number of occurances, we could use some other factor for determining the importance of an item (eg importance). We also could use some more advanced calculated value, for example we could say Featured Tags are more important and add an additional 1000 to their weight in addition to the count. For values the same applies, it doesn't need to be a font-size but could be used for ordering instead as well. Only Zend\\Tag\\Cloud uses these weights and values as font-sizes. But we could easily create another module that uses them for rendering an ordered list instead.

For your situation, the simple example would suffice already though:

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

// Add all tags and their count to it
foreach ($allTags as $tag) {
    $list[] = new Zend\Tag\Item(array('title' => $tag, 'weight' => countTagOccurences($tag));
}

// Assign font size values 
$list->spreadWeightValues(array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));


// Or to use the Zend\Tag\Cloud directly
$cloud = new Zend\Tag\Cloud(
    array(
        'tagDecorator' => array(
            'decorator' => 'htmltag',
            'options'   => array(
                'minFontSize' => '1',
                'maxFontSize' => '10',
         ),
     ),

     'tags' => $list
     )
);

Answer 2

The documentation is pretty clear (although not all that obvious); perhaps a better question is "What is 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.

http://framework.zend.com/manual/1.12/en/zend.tag.cloud.html

https://en.wikipedia.org/wiki/Tag_cloud

HTH.