Snippet: The Language snippet with tree matching functionality

<?php
/**
 * name Language
 * version 1.0 alpha (requires MODx 0.9.5+)
 * author Erik Pols <[email protected]>
 * 
 * license Public Domain, use as you like.
 * 
 * This snippet creates a language switch drop box. The page it points to is
 * approximated by trying to duplicate the path the current page is in, in the
 * other branches which are defined below in 'rootpages'.
 */

//$id= isset ($id) && intval($id) ? intval($id) : $modx->documentIdentifier;

include_once("assets/snippets/language/language.inc.php");

// define ISO codes -> Languages 
$langnames = array(
  "en" => "English",
  "fr" => "Français",
  "nl" => "Nederlands",
  "de" => "Deutsch"
);

// define rootpages
$rootpages = array(
  "en" => 2,
  "fr" => 68,
  "nl" => 67,
  "de" => 69
);

show_language_dropbox($langnames,$rootpages);
?>

<?php

function show_language_dropbox($langnames, $rootpages){
	global $modx;
	
	// get this ultimate parent
	$ultimate_parent = $modx->runSnippet('UltimateParent');

	// grab the tv's from every page in the path to the root for performance reasons
	$doc = $modx->getDocument($modx->documentIdentifier, "id");
	while ($doc['id'] != $ultimate_parent){
		$tvars[$doc['id']] = get_language_tv_array($doc['id']);
		$doc = $modx->getParent($doc['id'],1, 'id');
	}
		
	// there is a different path for every match we try to make because we stop the path when a TV helps us out
	foreach($langnames as $isocode => $langname){

		// first, we need to find the path to this page
		$mypath = array();
		$approximation = 0;
		
		// get the current doc 
		$doc = $modx->getDocument($modx->documentIdentifier, "id, menuindex");
		
		// traverse up in the tree, putting the path taken in mypath (note: it is in reversed order)
		while ($doc['id'] != $ultimate_parent){
			$tv_languages = $tvars[$doc['id']];

			// if this page has a tv with the corresponding page, we can begin our approximation here
			if($tv_languages[$isocode]){ 
				// we found a match in the tree structure, don't traverse any further
				$approximation = $tv_languages[$isocode];
				break;
			}
			else{
				// no luck. we have to add this one to the path and continue with the parent.
				$parent = $modx->getParent($doc['id'],1, 'id, menuindex');
				
				// we cannot trust the menuindex because indexes may be missing. base decision on the order. this is assuming getdocumentchildren is sorting on menuindex
				$index = 0;
				$siblings = $modx->getDocumentChildren($parent['id'],1,0,'id');
				foreach($siblings as $sibling){
					if($sibling['id']==$doc['id']) break;
					else $index++;
				}

				// add the current doc to the path 
				$entry['menuindex'] = $doc['menuindex'];
				$entry['id'] = $doc['id'];
				$entry['index'] = $index;
				$mypath[] = $entry;
				
				// now assign the new doc
				$doc = $parent;
				
			}
		}
		
		// if there was no page in the path with a template var set, assign the rootpage (we know that one at least)
		if(!$approximation) $approximation = $rootpages[$isocode];
		
		// walk down the branch, taking turns based on the menuindex
		for($i = count($mypath)-1;$i >= 0; $i--){
			// get the children
			$children = $modx->getDocumentChildren($approximation, 1,0, 'id, menuindex');

			// if the child exists in the good position, take it as the next approximation
			if($children[$mypath[$i]['index']]) $approximation = $children[$mypath[$i]['index']]['id'];
			else break;
		}
		
		// well that's it.
		$languages[$isocode] = $approximation;
		//echo $isocode.":".$approximation."<BR>";
	}
		
	?>
	<img src='assets/images/flags/<?php echo $rootpages[$ultimate_parent];?>.gif'>
	<form name="langform" action="#" method="post">
		<select name="langselect" id="langselect" onchange="window.location=document.langform.langselect.options[document.langform.langselect.selectedIndex].value">

		<?php 
		foreach ($languages as $lang => $page){ ?>
			<option value="<?php echo $modx->makeUrl($page);?>" <?php if($ultimate_parent == $rootpages[$lang]) echo 'SELECTED';?>><?php echo $langnames[$lang];?></option>
		<?}?>

		</select>
	</form>
	<?
}

function get_language_tv_array($id){
	global $modx;
	
	
	// get languages info from the TV
	$tv = $modx->getTemplateVar('languages', "", $id);
	$languagestring = $tv['value'];
	
	// modx copies 'default' to 'value'. we want an empty array instead of the default because we are going to approximate the path
	if($tv['value'] == $tv['default_text']) return array();

	// get entries in languages list
	$entries = explode(",", $languagestring);

	// parse the entries into a language->value array
	foreach($entries as $e){
		list($lang, $targetid) = explode("=", $e);
		$languages[$lang] = $targetid;
	}
	
	return $languages;
}

?>

<?php
$id = $modx->documentIdentifier;
$parent_id = $modx->runSnippet('UltimateParent', array("id" => $id));
// default
if (empty($id)) return "fi";
$doc = $modx->getDocumentObject('id',$parent_id);
return $doc['alias'];
?>