Zend Framework

/**
	 * Returns the query portion of the URL (after ?)
	 *
	 * @return array
	 */
	public function getQueryAsArray()
	{
		$queryParams = array();
		if($queryString = $this->getQuery()){
			$temp = explode('&', $queryString);
			foreach($temp as $param){
				list($key, $value) = explode('=', $param);
				$queryParams[$key] = $value;
			}
		}
        return $queryParams;;
	}
	
	
    /**
     * Add or replace params in the query string for the current URI, and return the old query 
     *
     * @param array $queryParams
     * @return string Old query string
     */
	public function addReplaceQuery($queryParams)
	{
		$queryParams = array_merge($this->getQueryAsArray(), $queryParams);
		return $this->setQuery($queryParams);
	}
	
    /**
     * Remove params in the query string for the current URI, and return the old query 
     *
     * @param array $queryParams
     * @return string Old query string
     */
	public function addReplaceQuery($queryParams)
	{
		$queryParams = array_diff($this->getQueryAsArray(), $queryParams);
		return $this->setQuery($queryParams);
	}