Module: ButtonToFormHelper

Defined in:
app/helpers/button_to_form_helper.rb

Class Attribute Summary collapse

Instance Method Summary collapse

Class Attribute Details

.content_for_name ⇒ Object

Returns the value of attribute content_for_name.



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# File 'app/helpers/button_to_form_helper.rb', line 3

def content_for_name
  @content_for_name
end

Instance Method Details

#button_to_form(button_text, url, button_options = {}, form_options = {}, &block) ⇒ Object

The [button_to](api.rubyonrails.org/classes/ActionView/Helpers/UrlHelper.html#method-i-button_to) provided by rails doesn’t work when used inside of a form tag, because it adds a new <form> and HTML doesn’t allow a form within a form. It does, however, allow a button/input/etc. to be associated with a different form than the one it is nested within.

The [HTML spec says](html.spec.whatwg.org/#association-of-controls-and-forms):

> A form-associated element is, by default, associated with its nearest ancestor form element > (as described below), but, if it is listed, may have a form attribute specified to override > this.

This helper takes advantage of that, rendering a separate, empty form in the footer, and then associating this button with it, so that it submits with that form’s action rather than the action of the form it is a descendant of.

By default, it will generate a unique id for the form. In its simplest form, it can be used as a drop-in replacement for Rails’s ‘button_to`. Example:

= button_to_form 'Make happy', [:make_happy, user]

If you need to reference this form in other places, you should specify the form’s id. You can also pass other ‘form_options`, such as `method`.

= button_to_form 'Delete', thing,
  {data: {confirm: 'Are you sure?'}},
  {method: 'delete', id: 'delete_thing_form'}
= hidden_field_tag :some_id, some_id, {form: 'delete_thing_form'}

You may pass along additional data to the endpoint via hidden_field_tags by passing them as a block. You don’t need to specify the form in this case because, as descendants, they are already associated with this form.

= button_to_form 'Delete', thing,
  {data: {confirm: 'Are you sure?'}},
  {method: 'delete'}
  = hidden_field_tag :some_id, some_id

If you call button_to_form with the same form id, it will render the button but will not render another form with the same id since it doesn’t make sense to have multiple forms with the same id. Instead it will assume you want another form that reuses (gets associated with) the existing form with that id.



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# File 'app/helpers/button_to_form_helper.rb', line 49

def button_to_form(button_text, url, button_options = {}, form_options = {}, &block)
  form_options[:id] ||= "form-#{SecureRandom.uuid}"
  @button_to_form_ids ||= []
  @button_to_form_id = form_options[:id]
  unless @button_to_form_ids.include?(@button_to_form_id)
    content_for(ButtonToFormHelper.content_for_name) do
      form_tag(url, **form_options) do
        block.call if block
      end
    end
  end
  @button_to_form_ids << @button_to_form_id

  button_tag(button_text, **button_options, type: 'submit', form: @button_to_form_id)
end