Allow overriding of default configured form_class

[rmm5t]

This is especially useful with bootstrap forms where you might want to switch to a form-inline layout even though the default is a form-horizontal.

e.g.

config.form_class = "form-horizontal" # configured default

simple_form_for @user, form_class: "form-inline"

I recognize that this was (somewhat) already proposed and closed in #657 and #639, but I feel like this new implementation is more straight forward, cleaner, and more discoverable without passing around non-standard html attributes. It's merely a config override.

Just throwing this out there.

[sman591]

👍 This is a simple solution that does exactly what Boostrap needs.

Example: I have an "inline" login form in my nav bar, however every other form on my application is "horizontal". Before this, an entire new helper would be needed just to change the form class. Now, all that would need to change is one variable - simple and prepared for future simple_form versions.

[rafaelfranca]

I'm reluctant to add a new option to set the form class. This will cause confusion with the html: { :class } option of simple_form_for. I don't see why use both in the same form, that said I prefer to keep using the same html: { :class } option of form_for and do not create a new option.

What we could improve is, if html: { :class } is not provided we use SimpleForm.form_class, otherwise we use only html: { :class }.

[rmm5t]

What we could improve is, if html: { :class } is not provided we use SimpleForm.form_class, otherwise we use only html: { :class }.

I'd be all for that. Plus, it would also better mimic the behavior of the html: { :novalidate } override.

I'd be happy to turn this pull-request into that implementation if you're open to it.

[rafaelfranca]

Please go ahead. It just can't happen in a 3.x version since it may break other people application. Maybe if we want to release in the next 3.x version we should add an option to enable and disable this new behaviour. I don't like the idea of adding a new global option but I don't have a better idea.

[rmm5t]

@rafaelfranca One more thing. If we make this change, I think SimpleForm.form_class should be deprecated in favor of SimpleForm.default_form_class.

Perhaps in the interim for 3.x, why don't we add default_form_class and that is the only thing overridden. Later, we can just remove support for form_class.

In other words, here's how I would configure my application for now in 3.x:

# config/initializers/simple_form.rb
config.default_form_class = "form-horizontal"
config.form_class = :simple_form # possibility for a deprecation warning now

Result:

# defaults
simple_form_for @thing
# <form class="simple_form form-horizontal" ... >

# inline override
simple_form_for @thing, html: { class: "form-inline" } 
# <form class="simple_form form-inline" ... >

[rafaelfranca]

Excellent idea 👍

[rmm5t]

@rafaelfranca Pull-request force-pushed to cover the new default_form_class option that we discussed. Code review and pull very much appreciated.

I made an update to the changelog too, but as a separate commit in case you didn't want me to make that update.

[rmm5t]

@rafaelfranca Any word on whether you think this pull-request can make it in before an official 3.1.0 release?

[rafaelfranca]

For me it is good. I remember @carlosantoniodasilva has some concerns but I don't remember what. I'll merge as soon I have time to work on Simple Form.

[futhr]

Loved to see this merged 👍

[rafaelfranca]

Thanks ❤️ 💚 💙 💛 💜

[bquorning]

I was surprised to see that there’s no link between this PR and the issue #1217. Well, now there is :-)