Help me improve this snippet

<?php
//I suppose this tells the snippet to look for the tpl to use
$itemChunk = $modx->getChunk($tpl);

//this extracts the album number from the link provided by facebook which is passed as a template variable in the snippets &album parameter
$parts = explode('.', $album);

//creates the url for the JSON data using the album number we extracted with explode
$facebook_album = file_get_contents("http://graph.facebook.com/".$parts[3]."/photos?fields=source,name&limit=".$limit);

//decodes the JSON data            
$dataArr = json_decode($facebook_album, true);

//Not sure what this is doing so would like clarification on this, from what I understand the tpl parameter of the snippet gets the tpl and applies it to the scriptProperties array not sure what ResoruceItem does
$tpl = $modx->getOption('tpl',$scriptProperties,'ResourceItem');

//for loop which sets a placeholder for the fields we will use from the provided JSON data
foreach ($dataArr['data'] as $d) {
    
    //sets an imageURL placeholder with the value of source in the JSON data
    $modx->setPlaceholder('imageURL', $d['source']);

    //sets a name placeholder with the value of the name in the JSON data
    $modx->setPlaceholder('name', $d['name']);
    
    //tells modx to apply the chunk to the output
    $output = $modx->getChunk($tpl);
   
   //if I used return it would only display the last result in the array echo displays all of the items I think this needs to be changed
   echo $output;
}

<?php
//this extracts the album number from the link provided by facebook which is passed as a template variable in the snippets &album parameter
$parts = explode('.', $album);
 
//creates the url for the JSON data using the album number we extracted with explode
$facebook_album = file_get_contents("http://graph.facebook.com/".$parts[3]."/photos?fields=source,name&limit=".$limit);
 
//decodes the JSON data            
$dataArr = json_decode($facebook_album, true);
 
//for loop which sets a placeholder for the fields we will use from the provided JSON data
foreach ($dataArr['data'] as $d) {
     
    //tells modx to apply the chunk to the output
    $output .= $modx->getChunk($tpl, $d);
    
   //if I used return it would only display the last result in the array echo displays all of the items I think this needs to be changed
   
}
return $output;

$output .= $modx->getChunk($tpl, $d);

getChunk($tpl, $array)

[[!getFacebookAlbums? &tpl=`facebookChunk.tpl` &parts=`whateverlinkgoeshere`]]

[[!getFacebookAlbums? &album=`2501` &tpl=`facebookChunk.tpl`]]

<?php

//creates the url for the JSON data using the album number we extracted with explode
$facebook_album = file_get_contents("http://graph.facebook.com/".$album."/photos?fields=source,name&limit=".$limit);
 
...

<?php

//get the tpl from scriptProperties, if not set, use tplFacebookAlbum as default - tpl
$tpl = $modx->getOption('tpl', $scriptProperties, 'tplFacebookAlbum');
$album = $modx->getOption('album', $scriptProperties, '');
$outputSeparator = $modx->getOption('outputSeparator', $scriptProperties, '');

//this extracts the album number from the link provided by facebook which is passed as a template variable in the snippets &album parameter
$parts = explode('.', $album);

//define output as empty array
$output = array();
if (!empty($tpl) && isset($parts[3])) {
    //creates the url for the JSON data using the album number we extracted with explode
    $facebook_album = file_get_contents("http://graph.facebook.com/" . $parts[3] . "/photos?fields=source,name&limit=" . $limit);
    //decodes the JSON data
    $dataArr = $modx->toJson($facebook_album);
    
    if (is_array($dataArr) && is_array($dataArr['data'])) {
        //for loop which sets a placeholder for the fields we will use from the provided JSON data        
        foreach ($dataArr['data'] as $d) {

            //tells modx to apply the chunk to the output
            $output[] = $modx->getChunk($tpl,$d);

            //if I used return it would only display the last result in the array echo displays all of the items I think this needs to be changed
        }
    }
}

// convert the output-array to string seperated by $outputSeparator
return implode($outputSeparator,$output);