add checkbox with simple_form without association

问题:

How I can add checkbox with simple_form without association with model? I want to create checkbox which will handle some javascript events, but don't know? Maybe I miss something in documentation? Want't to use similar like following:

= simple_form_for(resource, as: resource_name, url: session_url(resource_name), wrapper: :inline) do |f|
  .inputs
    = f.input :email, required: false, autofocus: true
    = f.input :password, required: false
    = f.input :remember_me, as: :boolean if devise_mapping.rememberable?
    = my_checkbox, 'some text'

回答1:

You can add a custom attribute to the model:

class Resource < ActiveRecord::Base
  attr_accessor :custom_field
end

Then use this field as block:

= f.input :custom_field, :label => false do 
  = check_box_tag :some_name

Try to find "Wrapping Rails Form Helpers" in their documentation https://github.com/plataformatec/simple_form

回答2:

You could use

f.input :field_name, as: :boolean

回答3:

The command proposed by huoxito does not work (at least not in Rails 4). As far as I figured out the error is caused by Rails trying to look up the default value for :custom_field, but because this field does not exists this lookup fails and an exception is thrown.

However, it works if you specify a default value for the field using the :input_html parameter, e.g. like this:

= f.input :custom_field, :as => :boolean, :input_html => { :checked => "checked" }

回答4:

This question comes first on google with no appropriate answer.

Since Simple Form 3.1.0.rc1 there is a proper way of doing it explained on the wiki: https://github.com/plataformatec/simple_form/wiki/Create-a-fake-input-that-does-NOT-read-attributes

app/inputs/fake_input.rb:

class FakeInput < SimpleForm::Inputs::StringInput
  # This method only create a basic input without reading any value from object
  def input(wrapper_options = nil)
    merged_input_options = merge_wrapper_options(input_html_options, wrapper_options)
    template.text_field_tag(attribute_name, nil, merged_input_options)
  end
end

Then you can do <%= f.input :thing, as: :fake %>

For this specific question you have to change the second line of the method to:

template.check_box_tag(attribute_name, nil, merged_input_options)

For versions prior 3.1.0.rc1 admgc gave a solution that is adding the missing method merge_wrapper_options:

https://stackoverflow.com/a/26331237/2055246

回答5:

Add this to app/inputs/arbitrary_boolean_input.rb:

class ArbitraryBooleanInput < SimpleForm::Inputs::BooleanInput
  def input(wrapper_options = nil)
    tag_name = "#{@builder.object_name}[#{attribute_name}]"
    template.check_box_tag(tag_name, options['value'] || 1, options['checked'], options)
  end
end

then use it in your views like:

= simple_form_for(@some_object, remote: true, method: :put) do |f|
  = f.simple_fields_for @some_object.some_nested_object do |nested_f|
    = nested_f.input :some_param, as: :arbitrary_boolean

i.e. The above implementation supports nested fields correctly. Other solutions I've seen do not.

Note: This example is HAML.