Answered How to count number of resources with date TV is-not-empty in a parent resource?

$count = 0;
$docArray = $modx->getIterator('modResource',array(
    'parent' => 42,
));
foreach($docArray as $doc) {
    $docid = $doc->get('id');
    $tv = $modx->getObject('modTemplateVar',array('name'=>'MyTV'));
    $rawValue = $tv->getValue($id); 
    if(isset($rawValue)) count++;
}
return $count;

$total = $modx->getCount('modTemplateVarResource', array('tmplvarid' => $tvID, 'value' != $value));
return $total;

[[!tvValueCount? &tvId=`2` &value=``]]

$total = $modx->getCount('modTemplateVarResource', array('tmplvarid' => $tvID, 'value' != $value, 'contentid:IN' => $child_ids));
return $total;

[[!tvValueCount? &tvId=`2` &parentId=`12` &value=``]]

$parentId = $modx->getOption('parentId', $scriptProperties, '');
$tvId = $modx->getOption('tvId', $scriptProperties, '');

if (empty($parentId)) {
    return 'No Parent Id Set';
}

if (empty($tvId)) {
    return 'No TV Id Set';
}

$childIds = $modx->getChildIds($parentId);
$total = $modx->getCount('modTemplateVarResource', array('tmplvarid' => $tvId, 'value' != $value, 'contentid:IN' => $childIds));
return $total;

$childIds = $modx->getChildIds($parentId);