SassForNode.php in Sassy 7

File

phamlp/sass/tree/SassForNode.php

<?php

/* SVN FILE: $Id$ */

/**
 * SassForNode class file.
 * This is an enhanced version of the standard SassScript @for loop that adds
 * an optional step clause. Step must evaluate to a positive integer.
 * The syntax is:
 * <pre>@for <var> from <start> to|through <end>[ step <step>]</pre>.
 *
 * <start> can be less or greater than <end>.
 * If the step clause is ommitted the <step> = 1.
 * <var> is available to the rest of the script following evaluation
 * and has the value that terminated the loop.
 * 
 * @author			Chris Yates <[e-mail]>
 * @copyright 	Copyright (c) 2010 PBM Web Development
 * @license			http://phamlp.googlecode.com/files/license.txt
 * @package			PHamlP
 * @subpackage	Sass.tree 
 */

/**
 * SassForNode class.
 * Represents a Sass @for loop.
 * @package			PHamlP
 * @subpackage	Sass.tree
 */
class SassForNode extends SassNode {
  const MATCH = '/@for\\s+[!\\$](\\w+)\\s+from\\s+(.+?)\\s+(through|to)\\s+(.+?)(?:\\s+step\\s+(.+))?$/i';
  const VARIABLE = 1;
  const FROM = 2;
  const INCLUSIVE = 3;
  const TO = 4;
  const STEP = 5;
  const IS_INCLUSIVE = 'through';

  /**
   * @var string variable name for the loop
   */
  private $variable;

  /**
   * @var string expression that provides the loop start value
   */
  private $from;

  /**
   * @var string expression that provides the loop end value
   */
  private $to;

  /**
   * @var boolean whether the loop end value is inclusive
   */
  private $inclusive;

  /**
   * @var string expression that provides the amount by which the loop variable
   * changes on each iteration
   */
  private $step;

  /**
   * SassForNode constructor.
   * @param object source token
   * @return SassForNode
   */
  public function __construct($token) {
    parent::__construct($token);
    if (!preg_match(self::MATCH, $token->source, $matches)) {
      throw new SassForNodeException('Invalid {what}', array(
        '{what}' => '@for directive',
      ), $this);
    }
    $this->variable = $matches[self::VARIABLE];
    $this->from = $matches[self::FROM];
    $this->to = $matches[self::TO];
    $this->inclusive = $matches[self::INCLUSIVE] === SassForNode::IS_INCLUSIVE;
    $this->step = empty($matches[self::STEP]) ? 1 : $matches[self::STEP];
  }

  /**
   * Parse this node.
   * @param SassContext the context in which this node is parsed
   * @return array parsed child nodes
   */
  public function parse($context) {
    $children = array();
    $from = (double) $this
      ->evaluate($this->from, $context)->value;
    $to = (double) $this
      ->evaluate($this->to, $context)->value;
    $step = (double) $this
      ->evaluate($this->step, $context)->value * ($to > $from ? 1 : -1);
    if ($this->inclusive) {
      $to += $from < $to ? 1 : -1;
    }
    $context = new SassContext($context);
    for ($i = $from; $from < $to ? $i < $to : $i > $to; $i = $i + $step) {
      $context
        ->setVariable($this->variable, new SassNumber($i));
      $children = array_merge($children, $this
        ->parseChildren($context));
    }
    return $children;
  }

}

Classes

Name	Description
SassForNode	SassForNode class. Represents a Sass @for loop. @package PHamlP @subpackage Sass.tree