<?php

/**
 * Component of HTMLPurifier_AttrContext that accumulates IDs to prevent dupes
 * @note In Slashdot-speak, dupe means duplicate.
 * @note The default constructor does not accept $config or $context objects:
 *       use must use the static build() factory method to perform initialization.
 */
class HTMLPurifier_IDAccumulator {
	
	/**
	 * Lookup table of IDs we've accumulated.
	 * @public
	 */
	public $ids = array ();
	
	/**
	 * Builds an IDAccumulator, also initializing the default blacklist
	 * 
	 * @param HTMLPurifier_Config $config
	 *        	Instance of HTMLPurifier_Config
	 * @param HTMLPurifier_Context $context
	 *        	Instance of HTMLPurifier_Context
	 * @return HTMLPurifier_IDAccumulator Fully initialized HTMLPurifier_IDAccumulator
	 */
	public static function build($config, $context) {
		$id_accumulator = new HTMLPurifier_IDAccumulator ();
		$id_accumulator->load ( $config->get ( 'Attr.IDBlacklist' ) );
		return $id_accumulator;
	}
	
	/**
	 * Add an ID to the lookup table.
	 * 
	 * @param string $id
	 *        	ID to be added.
	 * @return bool status, true if success, false if there's a dupe
	 */
	public function add($id) {
		if (isset ( $this->ids [$id] )) {
			return false;
		}
		return $this->ids [$id] = true;
	}
	
	/**
	 * Load a list of IDs into the lookup table
	 * 
	 * @param $array_of_ids Array
	 *        	of IDs to load
	 *        	@note This function doesn't care about duplicates
	 */
	public function load($array_of_ids) {
		foreach ( $array_of_ids as $id ) {
			$this->ids [$id] = true;
		}
	}
}

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