I had the same problem, and investigating the code, in the class ArticlesImportWordPress, there is a method, createArticle, and in it, reads the xml to read the post_type, with this line of code :
$postType = (string)$this->getXPath($item,'wp:post_type');
This is emptly, and nothing happens.
I have moved the line that gets the namespace "wp" :
$wp = $item->children('wp',true);
before this line, at the first position of the method, and changed the read of post_type by :
$postType = (string)$wp->post_type;
So, the method looks like this :
public function createArticle(SimpleXMLElement $item) {
$wp = $item->children('wp',true); // 2018-09-27 . moved here
//$postType = (string)$this->getXPath($item,'wp:post_type');
$postType = (string)$wp->post_type;
if ($postType != 'post') return false;
$settings = $this->container->getContainerSettings();
$creator = $this->matchCreator((string)$item->xpath('dc:creator'.'/text()'),1);
/** @var SimpleXMLElement $wp */
//$wp = $item->children('wp',true); // 2018-09-27 . moved
$pubDate = strtotime((string)$item->pubDate);
if (empty($pubDate)) {
$pubDate = strtotime((string)$wp->post_date);
}
/** @var Article $article */
$article = $this->modx->newObject('Article');
$article->fromArray(array(
'parent' => $this->container->get('id'),
'pagetitle' => $this->parseContent((string)$item->title),
'description' => $this->parseContent((string)$item->description),
'alias' => $this->parseContent((string)$wp->post_name),
'template' => $this->modx->getOption('articleTemplate',$settings,0),
'published' => $this->parsePublished($item),
'publishedon' => $pubDate,
'publishedby' => $creator,
'createdby' => $creator,
'createdon' => strtotime((string)$wp->post_date),
'content' => $this->parseContent((string)$item->children('content',true)->encoded),
'introtext' => $this->parseContent((string)$item->children('excerpt',true)->encoded),
'show_in_tree' => false,
'class_key' => 'Article',
'context_key' => $this->container->get('context_key'),
));
$article->setArchiveUri();
$article->setProperties($settings,'articles');
if (!$this->debug) {
$article->save();
}
$this->importTags($article,$item);
$this->importComments($article,$item);
return $article;
}
