How to use form_for with ViewModel

[st0mir]

How to use form_for helper in Cell::ViewModel?

Without including this helper I get error 'method undefined'. So I've tried to include it:
include ActionView::RecordIdentifier # this I need for method dom_class that is used by form_tag include ActionView::Helpers::FormHelper

but now input tags are not nested in form tag. It looks like this:
`<input ... />
<input ... />

`

Am I doing something wrong?

My rails version is 4.2.0

[apotonick]

You have to include ActionView::Helpers::FormHelper into your cell, and then define #dom_class and #dom_id in your cell as an instance method. This is a dependency from simple_form or Haml, I don't know exactly why one needs this.

We can think about a cells helper module that provides that out-of-the-box but on the other hand I want to increase the pain so that users like you report to Rails core and probably push them to remove those dependencies from core. 😬

[st0mir]

It still looks the same. I've added this two methods (delegate to ActionView::RecordIdentifier)

def dom_class(record, prefix = nil)
  ActionView::RecordIdentifier.dom_class(record, prefix)
end

def dom_id(record, prefix = nil)
  ActionView::RecordIdentifier.dom_id(record, prefix)
end

Both returns in my case 'new_article' (so I think value is ok), but form still doesn't render correctly:

<input type="text" name="article[title]" id="article_title" />
<form class="new_article" id="new_article"  ...></form>

I've also checked how it works in cells 4.0. So I included ActionView::Helpers::FormHelper to my cell class and implemented #dom_class and #dom_id methods (the same way as above). Here I get following exception:

NoMethodError - undefined method `encoding' for []:Array:
  actionview (4.2.0) lib/action_view/helpers/capture_helper.rb:197:in `with_output_buffer'
  haml (4.0.6) lib/haml/helpers/action_view_xss_mods.rb:5:in `with_output_buffer_with_haml_xss'
  actionview (4.2.0) lib/action_view/helpers/capture_helper.rb:38:in `capture'
  haml (4.0.6) lib/haml/helpers/action_view_mods.rb:52:in `capture_with_haml'
  actionview (4.2.0) lib/action_view/helpers/form_helper.rb:444:in `form_for'

Do you have any idea what I am doing wrong?

[seuros]

@st0mir can you try with my fork + addition of cells-haml ?
https://github.com/trailblazer/cells-haml

[st0mir]

It works but not without problems.

I've got exception:

NameError - uninitialized constant Cell::Haml::Util:
  activesupport (4.2.0) lib/active_support/dependencies.rb:533:in `load_missing_constant'
  activesupport (4.2.0) lib/active_support/dependencies.rb:184:in `const_missing'
   () home/vagrant/.rvm/gems/ruby-2.1.5/bundler/gems/cells-haml-b99589c7e68d/lib/cell/haml.rb:13:in `set_output_buffer_with_haml'
   () home/vagrant/.rvm/gems/ruby-2.1.5/bundler/gems/cells-haml-b99589c7e68d/lib/cell/haml.rb:46:in `ensure in with_output_buffer'

so, I've changed lib/cell/haml.rb:13 to if ::Haml::Util.rails_xss_safe? && new_buffer.is_a?(ActiveSupport::SafeBuffer).

There was also problem with two missing methods on String:

undefined method `safe_concat'
undefined local variable or method `output_buffer'

so I had to include to String this modules:

include ActionView::Helpers::TextHelper
include ActionView::Context

[seuros]

Can you send a PR ?

[Titinux]

I am also trying to use form_for in a cell but I have a problem that is not mentioned here.

no implicit conversion of nil into String

I use rails 4.2, cells master and cells-haml form_tag_with_body branch from st0mir

I checked the form_tag_with_body method in lib/cell/haml.rb (cells-haml) and the content parameter is nil. If I force the content to be an empty string it does not crash.

I would be glad to tell you more details if needed.

[seuros]

You should use either my fork or cell-4 branch. Master is too hacky.
@apotonick we should merge cell cell-4 to master.

[Titinux]

Same error with the cells-4 branch.

But if I change the form_tag_with_body method like this

def form_tag_with_body(html_options, content)
  content ||= ""
  "#{form_tag_html(html_options)}" << content << "</form>"
end

my problem is solved. (no idea of other consequences 😓)

[seuros]

I'm going to fix it

[apotonick]

This is just wrong per design - why is a view component library supposed to fix these kind of template engine details. I really hope we can set a usable standard with cells-haml etc. and push that knowledge back to Rails core itself for ActionView5.

I merged seuros cleanup, cells/cells-4 is now the authorative source for our future work. Thanks to @seuros for his work on extracting template engine specific logic to gems! ❤️ 🍻 ah no wait, he doesn't drink alcohol.... 🍵

[seuros]

🍸

[PikachuEXE]

I need the gem cells-haml for Cell::Concept using cells 3.x.

[seuros]

cells-haml is for cells 4.x only.

[PikachuEXE]

I guess I will just hack it myself Q_Q

[apotonick]

Why do you need that for cells 3 anyway, @PikachuEXE?

[PikachuEXE]

cells 3 also got Cell::Concept, and then I use simple_form in it...

[apotonick]

But... I don't understand... how is the Concept cell in Cells 3 related to HAML bugs that are fixed in cells-haml? In Cells 3, these fixes are shipped with the cells gem itself?

[PikachuEXE]

In one of my concept cell I need to use simple_form_for.
So I do this:

# Required by simple form for `form_for` I guess
include ActionView::RecordIdentifier
include ActionView::Helpers::FormHelper
include SimpleForm::ActionViewExtensions::FormHelper

Then it will out put escaped HTML
So I need to do include Cell::Haml too (code from cells-haml).
Also I need to include Cell::Haml last to make it work

[apotonick]

Would using cells 4.0 be a choice for you?

[PikachuEXE]

For now I would be using my hacks.
I got many "old cells" which inherits from Cell::Rails
I guess I don't have time refactoring until April

[apotonick]

Ok, if your hacks work, then I'm happy. Sorry for the inconvenience - everything will be better in Cells 4.

[shkm]

Just wanted to point out that this still doesn't work in Cells 4 (I'm not sure if it should; I'd like it to, but that's not my decision). Thankfully, @PikachuEXE descended like an angel, and sprinkled magical dust upon my code, allowing it to just work.

I'm using this concern to get it working with Formtastic:

module FormsForCells
  extend ActiveSupport::Concern

  included do
    include ActionView::RecordIdentifier
    include ActionView::Helpers::FormHelper
    include ActionView::Helpers::TextHelper
    include ActionView::Context
    include Formtastic::Helpers::FormHelper

    include Cell::Haml
  end
end

[apotonick]

You have to tell the formtastic guys to fix that in their code. They are not including necessary helpers in their modules and assume that everything is automatically/magically there, which is the case in Rails but not in Cells or in other Ruby environments.

Do me a favour and open a ticket there, telling them to include the necessary modules in Formtastic::Helper (or whatever the name of the "main" helper is). I could add a fix to Cells, but this way, it will never be fixed correctly. 🍻

[PikachuEXE]

Don't put and "workaround" (not fix) in this gem, no.
Another negative "rails style" 💣

[contentfree]

Thanks for the idea, @shkm. Using Cells 4 (and cells-rails and cells-haml and simple_form). I had to make a concern / module to include in my cells as the list of includes was as long as yours.

It would be nice if cells-rails or cells-haml would do some of this themselves, but I guess there's both pros and cons to having stuff automagically included into Cell::Concept