diff options
| -rw-r--r-- | railties/doc/guides/source/form_helpers.txt | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/railties/doc/guides/source/form_helpers.txt b/railties/doc/guides/source/form_helpers.txt index ba30c515bb..f04440f292 100644 --- a/railties/doc/guides/source/form_helpers.txt +++ b/railties/doc/guides/source/form_helpers.txt @@ -308,6 +308,8 @@ form_for(@article) Notice how the short-style `form_for` invocation is conveniently the same, regardless of the record being new or existing. Record identification is smart enough to figure out if the record is new by asking `record.new_record?`. It also selects the correct path to submit to and the name based on the class of the object. +Rails will also automatically set the class and id of the form appropriately: a form creating an article would have id and class `new_article`. If you were editing the article with id 23 the class would be set to `edit_article` and the id to `edit_article_23`. The attributes will be omitted or brevity in the rest of this guide. + WARNING: When you're using STI (single-table inheritance) with your models, you can't rely on record identification on a subclass if only their parent class is declared a resource. You will have to specify the model name, `:url` and `:method` explicitly. @@ -582,8 +584,22 @@ File upload form Scoping out form controls with `fields_for` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -Creates a scope around a specific model object like `form_for`, but doesn’t create the form tags themselves. This makes `fields_for` suitable for specifying additional model objects in the same form: - +`fields_for` creates a form builder in exactly the same way as `form_for` but doesn't create the actual `<form>` tags. In that sense it creates a scope around a specific model object like `form_for`, which is useful for specifying additional model objects in the same form. For example we might a Person model with an associated ContactDetail model. We could create a form for editing both like so: +------------- +<% form_for @person do |person_form| %> + <%= person_form.text_field :name %> + <% fields_for @person.contact_detail do |contact_details_form| %> + <%= contact_details_form.text_field :phone_number %> + <% end %> +<% end %> +------------- +which produces the following output: +------------- +<form action="/people/1" class="edit_person" id="edit_person_1" method="post"> + <input id="person_name" name="person[name]" size="30" type="text" /> + <input id="contact_detail_phone_number" name="contact_detail[phone_number]" size="30" type="text" /> +</form> +------------- Making custom form builders ~~~~~~~~~~~~~~~~~~~~~~~~~~~ |