Apart from a few missing tests, this PR is pretty much complete now. Feedback welcome.

@bschussek could be a good nice to have... after the 100+ form issues are tackled !

Support for validation groups in submit buttons added.

This PR is now complete. I adapted the description above.

@vicb I understand your frustration but I think your comment about the outstanding issues is uncalled for...

Nice addition @bschussek! I've long wondered why buttons are not a part of the framework 👍

That's nice, really, it's really useful and well-designed, so thanks @bschussek.

But as@vicb there are (a few) issues related to the Form component, and it would be nice to focus on fixing them (IMO).

Changing validation_group depending on the button is great, but I wonder if its a good idea to allow a event (onclick) when a button is clicked. I have some forms that have a 'cancel' button and depending which button is clicked 'submit' or cancel the form is either processed or the user is redirected to another page.

But as binding/bounding a complete form to determine if cancel was clicked could a performance hit, I wonder if its better to keep using the 'old' method for that.

And the 's label, its not uncommon to use HTML (Twitter Bootstrap for instance) knowing that Twig automatically escapes the label.

Changing validation_group depending on the button is great, but I wonder if its a good idea to allow a event (onclick) when a button is clicked.

@sstok What do you mean by that? Have you actually looked at the code of this PR?

But as binding/bounding a complete form to determine if cancel was clicked could a performance hit, I wonder if its better to keep using the 'old' method for that.

Performance is not affected (significantly) by this PR.

A was talking in general, in JavaScript you can apply an event handler on a button for when its clicked.
I was wondering if something similar would be useful for the Form component, as choosing the validation_group depending on which button was clicked can be seen as an event.

As an example I have form with a normal submit button for saving and a cancel button which when clicked redirects the user back to the viewing page. Currently I'm checking this with.

if ($this->request->request->has('cancel')) {$isCancelled =true;return$this->onCancel($items) ?:true;}$this->form->bind($this->request);if ($this->form->isValid()) {$this->onConfirm($items);returntrue;}

The form is only binded when its actually gonna be used, but as binding a form even tho I'm only checking if a button was checked could be performance hit (compared to what I'm using now). I was wondering if supporting events when clicked could be useful. It was just a thought.

@sstok I see. You can drop your thoughts in#6576 if you like.

Postponed to 2.3

I rebased this branch on master now, fixed a few issues and wrote the documentation that is linked above. Unless reviews discover problems, this PR is ready for merging.

The latest build fail seems to be unrelated to the content of this PR. The build succeeded on 5.4.

@bschussek see#7662

Rebased again.

+1 Usefull to ease the creation of multi step forms. It would be interesting to write a simple usage case sample for multipage forms.

👍 Very useful to detect the clicked button (eg: save / preview).

What is the BC break you mention in the description ?

@GromNaN copied from the changelog:[BC BREAK] setting the option "validation_groups" tofalsenow disables validation instead of assuming group "Default"
@bschussek it should be mentionned in the UPGRADE file at the root as it is a BC break

@stof Good point, added this.