/smarty/plugins/modifier.add_url_param.php

<?php

/**

* Smarty add_url_param modifier plugin

* ----------------------------------------

*

* This plugin adds parameters to existing URLs and is useful

* when you want to append or update a parameter without

* knowing anything about the contents of the existing

* URL.

*

* If any of the parameters passed to the modifier

* are already contained in the URL, their values

* are updated in the URL, rather than appending another

* parameter to the end.

*

* Examples:

*

*  {$smarty.server.REQUEST_URI|add_url_param:'param=test&param2=test2'}

*  {$smarty.server.REQUEST_URI|add_url_param:$paramArray}

*  {$smarty.server.REQUEST_URI|add_url_param:'variable':$value}

*

*

* @author Mark Mitchenall <mark@standingwave.co.uk>

* @copyright Standingwave Ltd, 2005

*

* @param $url         string  URL to add the parameters to

* @param $parameter   mixed   Assoc. Array with param names and

*                             values or string contain the

*                             additional parameter(s)

* @param $paramValue  string  (optional) Parameter value when

*                             $parameter contains just a

*                             parameter name.

* @return string

*/

function smarty_modifier_add_url_param($url, $parameter, $paramValue = NULL)

{



    if ($paramValue !== NULL) {

       

        // we were passed the parameter and value as

        // separate plug-in parameters, so just apply

        // them to the URL.

        $url = _addURLParameter ($url, $parameter, $paramValue) ;

       

    } elseif (is_array($parameter)) {

   

        // we were passed an assoc. array containing

        // parameter names and parameter values, so

        // apply them all to the URL.

        foreach ($parameter as $paramName => $paramValue) {

            $url = _addURLParameter ($url, $paramName, $paramValue) ;

        }



    } else {

   

        // was passed a string containing at least one parameter

        // so parse out those passed and apply them separately

        // to the URL.

       

        $numParams = preg_match_all('/([^=?&]+?)=([^&]*)/', $parameter, $matches, PREG_SET_ORDER) ;

       

        foreach ($matches as $match) {

            $url = _addURLParameter ($url, $match[1], $match[2]) ;

        }

       

    }

   

    return $url ;

}



function _addURLParameter ($url, $paramName, $paramValue) {



    // first check whether the parameter is already

    // defined in the URL so that we can just update

    // the value if that's the case.

   

    if (preg_match('/[?&]('.$paramName.')=[^&]*/', $url)) {



        // parameter is already defined in the URL, so

        // replace the parameter value, rather than

        // append it to the end.

        $url = preg_replace('/([?&]'.$paramName.')=[^&]*/', '$1='.$paramValue, $url) ;

   

    } else {

        // can simply append to the end of the URL, once

        // we know whether this is the only parameter in

        // there or not.

        $url .= strpos($url, '?') ? '&amp;' : '?';

        $url .= $paramName . '=' . $paramValue;



    }

    return $url ;

}

?>