Example of using PHP template engine twig in the YII framework _php instance

Twig is a fast, secure, flexible PHP template engine that has a built-in number of filter and tags and supports template inheritance, allowing you to use the simplest code to describe your template. His syntax is very similar to that of the template engine Jinjia in Python and the template syntax for Django. For example, when we need to output variables in PHP and escape them, the syntax is cumbersome:

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<?php Echo $var?>
<?php echo htmlspecialchars (\ $var, ent_quotes, ' UTF-8 ')?>

But you can write this in twig:

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{{var}}}
{{Var|escape}}}
{{var|e}}} {# shortcut to escape a variable #}

To traverse an array:

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{% for user in users%}
* {{User.Name}}
{% Else%}
No user has been found.
{% ENDFOR%}

But in the YII framework integration Twig will encounter a bit of trouble, the official web site has been able to integrate Twig program, so here I do not repeat. But because PHP syntax is not supported in twig, there are difficulties with some expressions, such as when we write a form's view:

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<?php $form = $this->beginwidget (' cactiveform ');?>
<span>Login</span>
<ul>
<li>
<?php echo $form->label ($model, ' username ');?>
<?php echo $form->textfield ($model, ' username ');?>

</li>

<li>
<?php echo $form->label ($model, ' password ');?>
<?php echo $form->passwordfield ($model, ' password ');?>

</li>

<li class= "Last" >
<button type= "Submit" >Login</button>

</li>

</ul>
<?php echo $form->error ($model, ' password ');?>
<?php $this->endwidget ();?>

But such a grammar cannot be expressed in twig, so you want to extend the functionality of the twig so that he can support our custom widget tags and automatically parse into the code we need. A total of two classes are required: Tokenparser and node, the following directly code:

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<?php
/*
* This file is a extension of Twig.
*
* (c) lfyzjck
*/

/**
 * Parser widget tag in Yii framework
 *
 * {% beginwidget ' cactiveform ' as form%}
&nbs p;*    content of form
 * {% endwidget%}
 *
 */
Class Yii_widgetblock_ Tokenparser extends Twig_tokenparser
{
   /**
     * Parses a token and Returns a node.
     *
     * @param twig_token $token A twig_token instance
 & nbsp;   *
     * @return twig_nodeinterface A twig_nodeinterface instance
 & nbsp;   */
    public Function parse (twig_token $token)
    {
        $lineno = $token->getline ();
        $stream = $this->parser->getstream ();

$name = $stream->expect (twig_token::string_type);
if ($stream->test (twig_token::P unctuation_type)) {
$args = $this->parser->getexpressionparser ()->parsehashexpression ();
}
else{
$args = new Twig_node_expression_array (Array (), $lineno);
}

$stream->expect (Twig_token::name_type);
$assign = $stream->expect (twig_token::name_type);
$stream->expect (Twig_token::block_end_type);

$body = $this->parser->subparse (Array ($this, ' Decideblockend '), true);
$stream->expect (Twig_token::block_end_type);

return new Yii_node_widgetblock Array (
' Alias ' => $name->getvalue (),
' Assign ' => $assign,
), $body, $args, $lineno, $this->gettag ());
}

/**
* Gets the tag name associated with this token parser.
*
* @param string The tag name
*/
Public Function Gettag ()
{
Return ' Beginwidget ';
}

Public Function Decideblockend (Twig_token $token)
{
return $token->test (' Endwidget ');
}
}

Class Yii_node_widgetblock extends Twig_node
{
    public function __construct ($attrs, Twig_ Nodeinterface $body, Twig_node_expression_array $args = NULL, $lineno, $tag)
    {
  & nbsp;     $attrs = array_merge (Array (' value ' => false), $attrs);
        $nodes = Array (' args ' => $args, ' body ' => $body);
        parent::__construct ($nodes, $attrs, $lineno, $tag);
   }

Public function compile (Twig_compiler $compiler)
{
$compiler->adddebuginfo ($this);
$compiler->write (' $context '. $this->getattribute (' Assign ')->getvalue (). ' "] = $context [" This "]-> Beginwidget ("'. $this->getattribute (' Alias ')."
$argNode = $this->getnode (' args ');
$compiler->subcompile ($argNode)
->raw ('); ')
->raw ("\ n");

$compiler->indent ()->subcompile ($this->getnode (' body '));

$compiler->raw (' $context ["This"]->endwidget (); ');
}
}
?>

Then add our syntax parsing classes where twig initializes:

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$twig->addtokenparser (new Yii_widgetblock_tokenparser);

Then we can write this in the twig template:

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{% Beginwidget ' cactiveform ' as form%}
<ul>
<li>
{{Form.label (model, ' username ')}}
{{Form.textfield (model, ' username ')}}
</li>
<li>
{{Form.label (model, ' Password ')}}
{{Form.passwordfield (model, ' Password ')}}
</li>
</ul>
{% Endwidget%}