Automaticaly create a page field from existing fields

[TomPich]

Hello all,

For my current project, each page have an image called thumbnail used for various purposes. If the thumbnail is not provided, I have a fallback image.
So on almost each PHP template, I have the following code at the beginning:

$thumbnailUrl = $page->pageThumbnail ? $page->pageThumbnail->size(1920, 400, ["crop" => "center"])->webp->url : $pages->get(1039)->configDefaultImage->url ;

To avoid repeating that on each page PHP template, what can I do to generate, for each page, something like $page->thumbnailUrl automatically? Do I have to use a hook ?

Thanks guys for your help

Cheers

Thomas

[bernhard]

You can either use hooks:

<?php
$wire->addHookMethod("Page::thumbnail", function(HookEvent $event) {
	$event->return = ...;
});

Or even better you use custom page classes (it's really easy thx to pw!) and there you create a DefaultPage class that adds your method:

<?php namespace ProcessWire;
class DefaultPage extends Page {
  public function thumbnail() {
    return ...;
  }
}

Then you just make sure that thumbnail() always returns a PageImage object and then in all your templates you can do this:

echo $page->thumbnail()->size(100,100)->webp->url;

And it will automatically render either the custom or the fallback image.

Check out https://processwire.com/blog/posts/pw-3.0.152/#new-ability-to-specify-custom-page-classes for details

[TomPich]

Thank you very much, Bernhard. This DefaultPage class will be very handy for a lot of stuff !