"Add hook after save" and create child page, but do nothing after further saves

[louisstephens]

So I have been diving into hooks lately, and I am enjoying them thus far. However, I guess I am a bit stumped on how to achieve what I want too. I am trying to set up a hook that would create a new child page when the parent page is saved. However, when you save the parent page a second time, I just need to update the child page without creating multiple child pages. What would be the best way to go about this?

So after rereading my post, I believe it is a bit vague so I will try to explain more. 

The Goal:

1. Create a page with a template "one".
2. Once the page is created/saved => create a new child page with the template of "two"
3. If the parent is saved anytime after, do nothing to the child page (limit the parent page to one child page)

The parent page is really just being used to output content, whereas the child page is being used to pull out the some fields from the parent to be used elsewhere. I might have made this too complicated in my head.

Edited February 6, 2019 by louisstephens
Trying to provide more clarification.

[elabx]

If I understand correctly, something  like this should work, let us know if you need more detail: 

wire()->addHookekAfter("Pages:saved", function($e){
	$page = $e->arguments(0);
	if($page->template == "one"){
		$pageTwo = $page->child("template=two");
		if(!$pageTwo->id){
			//create child page code and save!
		}
	}
});

 

[bernhard]

12 hours ago, louisstephens said:

So I have been diving into hooks lately, and I am enjoying them thus far.

Better late than never ? ? 

You can use Pages::added for this: https://processwire.com/api/ref/pages/added/

And using conditional hooks (https://processwire.com/blog/posts/new-ajax-driven-inputs-conditional-hooks-template-family-settings-and-more/#new-conditional-hooks) it gets even easier and cleaner:

$wire->addHookAfter('Pages::added', function(HookEvent $event) {
  $page = $event->arguments(0);
  bd($page);
});

I always start with the basic hook and test it. In this case this was quite interesting, because it fired twice! The reason is that this page contains a repeater matrix that creates a page for the first (possible) item:

Then you can modify the hook to be more specific:

$wire->addHookAfter('Pages::added(template=basic-page)', function(HookEvent $event) {
  $page = $event->arguments(0);
  bd($page);
});

Voila, it fires on the right page only:

And it will not fire on any further publish/save/etc events ? 

[louisstephens]

Thanks @bernhard! That was exactly what I was looking for. Now I'll continue down the path of learning hooks, and hopefully stop making mistakes like:

$p = new Page();
$u->template = "scripts";
$u->parent = wire('pages')->get($page->id);
$u->title = "Test";
$u->name = "test";
$u->save();

Which obviously just blows up in your face.?