yii2-taggable

Manage tags of ActiveRecords in PHP-framework Yii 2.0

This package contains five classes to handle the tagging of ActiveRecords with keywords or similar. The tags can be associated with or decoupled from a model (ActiveRecord), and can be sorted. Tags are manipulated with the excellent jQuery tagEditor developed by Pixabay.

The four main classes of yii2-taggable are:

• TagBehavior - makes an ActiveRecord behave like a tag;
• TaggableBehavior - adds the handling of tags to an ActiveRecord;
• TagEditor - widget to manipulate tags;
• TagSuggestAction - feeds the autocomplete function of TagEditor with data.

There is also a class TagEditorAsset, which is a helper class for TagEditor.

A demonstration of the yii2-taggable suit is here.

Notice that the API for version 2 is slightly different from that of version 1.

Installation

The preferred way to install yii2-taggable is through Composer. Either add the following to the require section of your composer.json file:

"sjaakp/yii2-taggable": "*"

Or run:

composer require sjaakp/yii2-taggable "*"

You can manually install yii2-taggable by downloading the source in ZIP-format.

Setup

Suppose we have a class (ActiveRecord) Article of articles which can be tagged, and another class Tag to hold the tags.

Tag has at least the following attributes:

• id: primary key;
• name: to hold the actual tag keyword;

Junction table

Article and Tag are linked with a junction table in a many-to-many relation.
Let's call the table article_tag. It has the following fields:

• model_id: holds the primary key value of an Article;
• tag_id: holds the primary key value of a Tag;
• ord: holds the sorting order of a Tag.

The junction table doesn't need to have a primary key.
It's a good idea to set indexes on both model_id and tag_id.

TaggableBehavior

The class Article is taggable, and should be set up like this:

<?php

namespace app\models;

use sjaakp\taggable\TaggableBehavior;

class Article extends ActiveRecord    {

	public function behaviors()
	{
        return [
            'taggable' => [
                'class' => TaggableBehavior::class,
                'junctionTable' => 'article_tag',
                'tagClass' => Tag::class,
            ]
        ];
    }
	// ...
}

TagBehavior

Class Tag behaves as a tag, and looks something like this:

<?php

namespace app\models;

use sjaakp\taggable\TagBehavior;

class Tag extends ActiveRecord    {

	public function behaviors()
	{
        return [
            'tag' => [
                'class' => TagBehavior::class,
                'junctionTable' => 'article_tag',
                'modelClass' => Article::class,
            ]
        ];
    }

	// ...
}

After attaching TagBehavior the class Tag. gains a few new properties and methods.
A link to the Tag view can be obtained by:

$link = $tag->link;

models gets all Articles tagged by $tag:

$taggedArticles = $tag->models;

If you'd rather have an ActiveDataProvider
to access them, use:

$providerOfTaggedArticles = $tag->getModels();

The count of tagged Articles:

$countTaggedArticles = $tag->modelCount;         

Article view

In the Article view we can now display the tags like so:

<?php
	// ...
/**
 * @var yii\web\View $this
 * @var ap\models\Article $model
 */
?>

<!-- Display article title and body here. -->

<h4>Tags</h4>
<p><?= $model->tagLinks ?></p>

tagLinks is a new virtual attribute, added to Article by TaggableBehavior.

All the Tags can be retrieved with:

$allTags = $article->tagModels;

To get an ActiveQuery,
for instance to use in an ActiveDataProvider,
use:

$provider = new ActiveDataProvider([
    'query' => $article->getTagModels()
]);

If you want to know whether an Article has a Tag with a certain name, say 'politics',
you can query the class like so:

if ($article->hasTag('politics'))   {
    // ...
}

Article update

To make creating and updating Tags easy, we also have to set up TagController:

<?php

namespace app\controllers;

use yii\web\Controller;
use app\models\Tag;
use sjaakp\taggable\TagSuggestAction;

class TagController extends Controller	{

    public function actions()    {
        return [
            'suggest' => [
                'class' => TagSuggestAction::class,
                'tagClass' => Tag::class,
            ],
        ];
    }

	// ...
}

TagEditor

In the Article's update and create views we can now use the TagEditor widget. Add something like this to views\article\_form.php:

<?php

use yii\helpers\Url;
use sjaakp\taggable\TagEditor;

/**
 * @var yii\web\View $this
 * @var app\models\Article $model
 * @var yii\widgets\ActiveForm $form
 */
?>
	...

    <?= $form->field($model, 'tags')->widget(TagEditor::class, [
        'clientOptions' => [
            'autocomplete' => [
                'source' => Url::toRoute(['tag/suggest'])
            ],
        ]
    ]) ?>
	...

tags is also a new virtual attribute of Article, added to it by TaggableBehavior.
'tag/suggest' is the base of the route to the suggest action in TagController,
which we defined before. Learn more about the clientOptions from Pixabay.

Modifications

The basic setup of yii2-taggable can be modified in a number of ways.
Refer to the source files to see which other options are available. Some are:

• nameAttribute: name attribute of the tag class.
  Defined in TagBehavior, TaggableBehavior, and TagSuggestAction. Default: 'name'.
• tagKeyColumn and modelKeyColumn: foreign key fields in the junction table.
  Defined in TagBehavior and TaggableBehavior.
  Defaults: 'tag_id' and 'model_id' respectively.
• orderColumn: holds order information in the junction table.
  Defined in TaggableBehavior.
• renderLink: callable, function($tag, $options), returning the HTML code for a single
  tag link. Defined by TagBehavior. If not set (default), TagBehaviour renders
  tag link as a simple HTML a.