<?php /* SVN FILE: $Id: SassVariableNode.php 118 2010-09-21 09:45:11Z chris.l.yates@gmail.com $ */ /**

* SassVariableNode class file.
* @author                      Chris Yates <chris.l.yates@gmail.com>
* @copyright   Copyright (c) 2010 PBM Web Development
* @license                     http://phamlp.googlecode.com/files/license.txt
* @package                     PHamlP
* @subpackage  Sass.tree
*/

/**

* SassVariableNode class.
* Represents a variable.
* @package                     PHamlP
* @subpackage  Sass.tree
*/

class SassVariableNode extends SassNode {

const MATCH = '/^([!$])([\w-]+)\s*:?\s*((\|\|)?=)?\s*(.+?)\s*(!default)?;?$/i';
const IDENTIFIER = 1;
const NAME = 2;
const SASS_ASSIGNMENT = 3;
const SASS_DEFAULT = 4;
const VALUE = 5;
const SCSS_DEFAULT = 6;
const SASS_IDENTIFIER = '!';
const SCSS_IDENTIFIER = '$';

/**
 * @var string name of the variable
 */
private $name;
/**
 * @var string value of the variable or expression to evaluate
 */
private $value;
/**
 * @var boolean whether the variable is optionally assigned
 */
private $isDefault;

/**
 * SassVariableNode constructor.
 * @param object source token
 * @return SassVariableNode
 */
public function __construct($token) {
        parent::__construct($token);
        preg_match(self::MATCH, $token->source, $matches);
        if (empty($matches[self::NAME]) || ($matches[self::VALUE] === '')) {
                throw new SassVariableNodeException('Invalid variable definition; name and expression required', array(), $this);                       
        }
        $this->name = $matches[self::NAME];
        $this->value = $matches[self::VALUE];
        $this->isDefault = (!empty($matches[self::SASS_DEFAULT]) || !empty($matches[self::SCSS_DEFAULT]));

        // Warn about deprecated features
        if ($matches[self::IDENTIFIER] === self::SASS_IDENTIFIER) {
                $this->addWarning('Variables prefixed with "!" is deprecated; use "${name}"', array('{name}'=>$this->name));
        }
        if (!empty($matches[SassVariableNode::SASS_ASSIGNMENT])) {
                $this->addWarning('Setting variables with "{sassDefault}=" is deprecated; use "${name}: {value}{scssDefault}"', array('{sassDefault}'=>(!empty($matches[SassVariableNode::SASS_DEFAULT])?'||':''), '{name}'=>$this->name, '{value}'=>$this->value, '{scssDefault}'=>(!empty($matches[SassVariableNode::SASS_DEFAULT])?' !default':'')));
        }               
}

/**
 * Parse this node.
 * Sets the variable in the current context.
 * @param SassContext the context in which this node is parsed
 * @return array the parsed node - an empty array
 */
public function parse($context) {
        if (!$this->isDefault || !$context->hasVariable($this->name)) {
                        $context->setVariable(
                                $this->name, $this->evaluate($this->value, $context)
                        );
        }               
        $this->parseChildren($context); // Parse any warnings
        return array();
}

/**
 * Returns a value indicating if the token represents this type of node.
 * @param object token
 * @return boolean true if the token represents this type of node, false if not
 */
public static function isa($token) {
        return $token->source[0] === self::SASS_IDENTIFIER || $token->source[0] === self::SCSS_IDENTIFIER;
}

}