From 58a75ffbfe7ee622a4a8551b2bfbbe01b396135e Mon Sep 17 00:00:00 2001 From: Mauro George Date: Sat, 13 Jun 2015 15:01:56 -0300 Subject: [PATCH] Add gotcha to RDoc of collection_check_boxes [ci skip] --- .../helpers/form_options_helper.rb | 21 +++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/actionview/lib/action_view/helpers/form_options_helper.rb b/actionview/lib/action_view/helpers/form_options_helper.rb index d3deee0df3..1b7b188d65 100644 --- a/actionview/lib/action_view/helpers/form_options_helper.rb +++ b/actionview/lib/action_view/helpers/form_options_helper.rb @@ -707,6 +707,27 @@ def collection_radio_buttons(object, method, collection, value_method, text_meth # collection_check_boxes(:post, :author_ids, Author.all, :id, :name_with_initial) do |b| # b.label(:"data-value" => b.value) { b.check_box + b.text } # end + # + # ==== Gotcha + # + # When no selection is made for a collection of checkboxes most + # web browsers will not send any value. + # + # For example, if we have a +User+ model with +category_ids+ field and we + # have the following code in our update action: + # + # @user.update(params[:user]) + # + # If no +category_ids+ are selected then we can safely assume this field + # will not be updated. + # + # This is possible thanks to a hidden field generated by the helper method + # for every collection of checkboxes. + # This hidden field is given the same field name as the checkboxes with a + # blank value. + # + # In the rare case you don't want this hidden field, you can pass the + # include_hidden: false option to the helper method. def collection_check_boxes(object, method, collection, value_method, text_method, options = {}, html_options = {}, &block) Tags::CollectionCheckBoxes.new(object, method, self, collection, value_method, text_method, options, html_options).render(&block) end -- GitLab