ProcessWire - Render Funktionen

Hier eine Übersicht über verschiedene Möglichkeiten Files, Felder und Templates zu rendern.

Links

ProcessWire - Page Rendering Functions
ProcessWire - Rendering Funktionen
ProcessWire - Rendering Templates mit fields Ordner
https://processwire.com/blog/posts/processwire-3.0.7-expands-field-rendering-page-path-history-and-more/#theres-also-page-gt-rendervalue
https://processwire.com/api/ref/page/render-value/

Kleine ProcessWire Renderübersicht

Die häufigsten...

$page->render($filename); // $filename (including .php) assumed in /site/templates/
$page->render($pathname); // $pathname is full path, but must resolve somewhere in web root
$page->render($filename, $myArray); // $myArray can be accessed via $options in Template
$page->render($fieldname) // short for $page->renderField() IF parameter is a fieldname - then pw looks for template file in /fields

// render the pages using templates/fields/myFieldTemplate and access ther with $page->
$page->renderValue($myPageArray, 'myFieldTemplate'); 
$page->renderValue($myValue, 'templateName'); // 

$files->render('teasers', ['items' => $pages->find("template=article")]); // mostly for delayed output
wireRenderFile('my_template', array('pid' => $child->id)); // old version of $files->render
wireIncludeFile() // for direct output

//$page->render() is intended for rendering a specific page (optionally using a specific file)
//wireRenderFile() renders a specific file without the need for a Page object

Use Cases und Unterschiede

$page->render('some_field') does indeed call renderField(), but only if the given param is a field name. Take a look at PageRender for more details. If you provide a filename as a param, $page->render() will use that file to render given page.

If you provide a filename (actual filename, not just something like "file") to $page->render() as the first param, you can provide an array as the second param, and the values stored in that array can then be accessed via $options.

It seems to me that you're trying to use $page->render() to something it's really not meant for: $page->render() is intended for rendering a specific page (optionally using a specific file), while wireRenderFile() renders a specific file without the need for a Page object. Those are two different use cases.