Template families and inherited fields

[Oliver]

As I’m getting a bit more into the e-commerce idea I was talking about in one of the other threads, I have been thinking about the PW template system. In a shop system you’d need a kind of basic product template with certain necessary fields like default price or something like that. But you’d also need the possibility to have variations of a product template, where additional fields can be defined individually for a certain kind of product. I know that there is the possibility to clone fields from an existing template. But I don’t think, that is a good solution for this particular problem, as you were able to delete some of the basic product data fields.

So my thought was, that it maybe would be a cool thing to be able to define a kind of relationship between templates. Like a class extending another one you could define an existing template as parent and the child template would inherit all fields and settings. New fields could be added, the inherited fields were kind of protected, the settings could be overridden by the ones defined for the child templates.

I guess, this could be achieved by a module pretty easily. But I think it could also be a pretty nice enhancement as a core feature.

[WillyC]

i like pw simple. this scare me a bit

but i like you.too always,very smartgood ideas,but hope they.keep just for module,not cores

Edited February 2, 2012 by WillyC

[ryan]

Good and interesting ideas Oliver. I'm not sure how simple this one would be to implement, but it's something I need to keep thinking about--maybe there is a simple way to do it.

[wheelmaker24]

What about enhancing the "Add field" select in the template editing window to not only feature fields but also existing templates? When choosing a template as a field, all of its fields are added to the new template and updated in case the original template is edited.

[LostKobrakai]

… and updated in case the original template is edited.

That's the difficult part as nobody can guess if you really want those fields to change or if you've maybe changed one of those fields just for that single template and won't want your changes to be overwritten.

[wheelmaker24]

I think the fields themselves don't need to be updated – the standard behaviour should be fine. I just meant that fields you've added to the original template are automatically added to the "child" template as well.

[mn-martin]

Consider this:

1. You have a view to choose a set of fieldgroups / templates
2. Once selected you'll get a list of matching fields (Only those fields that are used withing all fieldgroups of the initial selection)
3. Applied changes will be reflected on all fieldgroups

This would remove the need to maintain any sort of inheritance meta data but should be quite flexible.

Maybe you can even add bookmarks for your fieldgroup selections.

I consider developing such a module but I'd really like to hear from you guys whether there may be some drawbacks.

[mn-martin]

Just implemented a very simple fieldgroup inheritance module. I thought it may be helpful to others. Any insights on issues that may occur using this are very welcome if you find some.

protected $relations = [
	'foo' /* parent fieldgroup name */ => [
		[
			'template_name' => 'bar',
			'auto_remove_fields' => true,
		]
	]
];

public function init() {
	$this->addHookBefore('Fieldgroups::save', $this, 'syncFields');
}

public function syncFields( HookEvent $event ) {
	$fieldgroup = $event->arguments[0];

	if ( ! array_key_exists($fieldgroup->name, $this->relations)) return;

	$processTemplate = $this->modules->get('ProcessTemplate');
	$importFieldgroup = new ReflectionMethod('ProcessTemplate', 'importFieldgroup');
	$importFieldgroup->setAccessible(true);
	$removedFields = $fieldgroup->removedFields;

	foreach ($this->relations[$fieldgroup->name] as $relation) {
		$template = $this->templates->get($relation['template_name']);
		$importFieldgroup->invoke($processTemplate, $fieldgroup, $template);

		if ($removedFields && $relation['auto_remove_fields']) {
			foreach ($removedFields->getArray() as $fieldName) {
				$this->message('Removing field "' . $fieldName . '" from fieldgroup "' . $template->fieldgroup->name . '"');
				$field = $this->fields->get($fieldName);
				$template->fieldgroup->remove($field);
			}
		}

		$template->fieldgroup->save();
	}
}