calling a chunk that contains a snippet from a module - the snippet doesn't work

function runSnippetFromChunkForModule($string){
   global $modx;
   $snippets = array();
   $snippetPair = array();
   $snippetCallComponents = array();

   $explodedChunk = explode('[[',$string);
   foreach($explodedChunk as $snippet){

      $length = strpos($snippet, ']]');
      if($length){
         $snippet = substr($snippet,0,$length);
         $snippetCallComponents=parseSnippetCall($snippet);
         $snippetOutput = $modx->runSnippet($snippetCallComponents[0] ,$snippetCallComponents[1]);
         $newChunk = str_replace('[['.$snippet.']]',$snippetOutput,$string);
      }
   }

   return $newChunk;
}

function parseSnippetCall($string){
   $snippetCallBits = array();
   $snippetCallComponents = array();
   $snippetArgumentPairs = array();
   $argumentsBits = array();
   $arguments = array();

   $snippetCallBits = explode('?',$string);
   $snippetName = trim($snippetCallBits[0]);
   //$snippetName = substr($snippetName, 0, strlen($snippetName)-1);
   array_push($snippetCallComponents, $snippetName);

   $snippetArgumentPairs = explode('&', $snippetCallBits[1]);

   foreach($snippetArgumentPairs as $argumentPair){
     if(strpos($argumentPair,'=')){
        $argumentBits = explode('=',$argumentPair);
        $argumentName = trim($argumentBits[0]);
        $argumentValue = substr($argumentBits[1],1,strlen($argumentBits[1])-2);
        $arguments[$argumentName] = $argumentValue;
     }
   }
   array_push($snippetCallComponents, $arguments);

   return $snippetCallComponents;

}