Example of using PHP template engine Twig in Yii framework_PHP tutorial

Twig is a fast, safe, and flexible PHP template engine. It has many built-in filters and tags, and supports template inheritance, allowing you to use the most concise code to describe your template. Its syntax is very similar to the template engine Jinjia under Python and the template syntax of Django. For example, when we need to output variables and escape them in PHP, the syntax is cumbersome:

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But in Twig you can write like this:

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

Traverse the array:

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{% for user in users %}
* {{ user.name }}
{% else %}
No user has been found.
{% endfor % }

But it will be a bit troublesome to integrate Twig in Yii Framework. The official website already has a solution to integrate Twig, so I won’t go into details here. However, since Twig does not support PHP syntax, we will encounter difficulties in some expressions. For example, when we write the view of the Form, we often write like this:

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beginWidget('CActiveForm'); ?>
Login> ;
                                                                                                        form->textField($model,'username'); ?>

label($model,'password'); ?>

,'password'); ?>

Login

  error($model,'password'); ?>

endWidget(); ?>

But such syntax cannot be expressed in twig, so I want to extend the function of Twig so that it can support our customized widget tags and then automatically parse it into the code we need. . A total of two classes are needed: TokenParser and Node. The code is directly below:

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The code is as follows:

/*
 * This file is an extension of Twig.
 *
 * (c) 2010 lfyzjck
 */

/**
 * parser widget tag in Yii framework
 *
 * {% beginwidget 'CActiveForm' as form %}
 *    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
     *
     * @return Twig_NodeInterface A Twig_NodeInterface instance
    */
    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::PUNCTUATION_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)
    {
        $attrs = array_merge(array('value' => false),$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 class where Twig is initialized:

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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 %}

• 
  {{ form.label(model, 'username') } }
  {{ form.textField(model, 'username') }}
  


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  {{ form.label(model, 'password') }}
  {{ form.passwordField(model, 'password') }}
  

{% endwidget %}

http://www.bkjia.com/PHPjc/802218.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/802218.htmlTechArticleTwig is a fast, safe and flexible PHP template engine. It has many built-in filters and tags and supports Template inheritance allows you to use the most concise code to describe your template. His language...