Meta tags in Ditto

I am trying to display the meta tag for "author" in my ditto line for documents (rather than the creator of the page; for me they are different). I have a snippet that gets the meta tag author and sets a placeholder [+meta-author+] with the correct data. I can call the snippet as [[GetAuthor]] in my ditto template, and that produces an author, but does not produce the correct author for each page (I believe, because it is cached it only gets it the first time). I tried using [!GetAuthor!] in all the ways I could think of, but all I end up with is the literal string ’[!GetAuthor!]’ in my author line.

Has anyone tackled this kind of issue? Is there something obvious I am missing?

My Ditto Call:
[!Ditto?parents=`[*id*]`&display=`all`&tpl=`ArticleDitto`!]

My ditto template:
<div class="ditto_item" id="ditto_item_[+id+]">
<h3 class="ditto_pageTitle"><a href="[~[+id+]~]">[+pagetitle+]</a></h3>
<div class="ditto_documentInfo">by <strong>[[GetAuthor]][+meta-author+]</strong> on [+date+]</div>
<div class="ditto_introText">[+introtext+]</div>
</div>

Other attempts in the template:
<div class="ditto_item" id="ditto_item_[+id+]">
<h3 class="ditto_pageTitle"><a href="[~[+id+]~]">[+pagetitle+]</a></h3>
<div class="ditto_documentInfo">by <strong>`[!GetAuthor!]`[+meta-author+]</strong> on [+date+]</div>
<div class="ditto_introText">[+introtext+]</div>
</div>

<div class="ditto_item" id="ditto_item_[+id+]">
<h3 class="ditto_pageTitle"><a href="[~[+id+]~]">[+pagetitle+]</a></h3>
<div class="ditto_documentInfo">by <strong>`[!GetAuthor!][+meta-author+]`</strong> on [+date+]</div>
<div class="ditto_introText">[+introtext+]</div>
</div>

<div class="ditto_item" id="ditto_item_[+id+]">
<h3 class="ditto_pageTitle"><a href="[~[+id+]~]">[+pagetitle+]</a></h3>
<div class="ditto_documentInfo">by <strong>[!GetAuthor!][+meta-author+]</strong> on [+date+]</div>
<div class="ditto_introText">[+introtext+]</div>
</div>

Any help greatly appreciated.

P

What does the GetAuthor snippet look like? The easiest way is to just define an author TV and use that TV-name in the Ditto-tpl. No additional snippet is then needed to fetch this value.

Thanks for responding.

My GetAuthor looks like:
<?php
$pageMeta = $modx->getMETATags($modx->documentIdentifier);
$authorName = "Toghers";
foreach($pageMeta as $outerMeta)
{
if ($outerMeta["tag"] == "author")
{
$authorName = $outerMeta["tagvalue"];
break;
}
}

$modx->setPlaceholder("meta-author",$authorName);
?>

I have also tried returning the $authorName rather than setting the placeholder.

I found a solution for this.

I have a snippet GetAuthor:
<?php
$pageMeta = $modx->getMETATags($articleId);
$authorName = "Toghers";
foreach($pageMeta as $outerMeta)
{
if ($outerMeta["tag"] == "author")
{
$authorName = $outerMeta["tagvalue"];
break;
}
}

return $authorName;
?>

I have a chunk for my Ditto template:
<div class="ditto_item" id="ditto_item_[+id+]">
<h3 class="ditto_pageTitle"><a href="[~[+id+]~]">[+pagetitle+]</a></h3>
<div class="ditto_documentInfo">by <strong>[[GetAuthor?&articleId=`[+id+]`]]</strong> on [+date+]</div>
<div class="ditto_introText">[+introtext+]</div>
</div>

and I have a Ditto call:
[!Ditto?parents=`33`&filter=`template,21,1` &depth=`10`&tpl=`ArticleDitto`!]

where parents=`33` and template 21 are specific to my site. It does a fine job of rendering an author if there is one, and a default (Toghers) if there is not