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| author | Eloy Duran <eloy.de.enige@gmail.com> | 2009-03-15 16:21:56 +0100 |
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| committer | Eloy Duran <eloy.de.enige@gmail.com> | 2009-03-15 16:22:14 +0100 |
| commit | 3b89aa605c543e772678e03add1818520c02bec8 (patch) | |
| tree | 0140516257408e05a140bea6c4e5c0b84068f9e8 /railties/guides/source | |
| parent | 13cc934cc8510aef0aa3989c118996bc508a985f (diff) | |
| download | rails-3b89aa605c543e772678e03add1818520c02bec8.tar.gz rails-3b89aa605c543e772678e03add1818520c02bec8.tar.bz2 rails-3b89aa605c543e772678e03add1818520c02bec8.zip | |
Added a collection association form example.
Diffstat (limited to 'railties/guides/source')
| -rw-r--r-- | railties/guides/source/nested_model_forms.textile | 47 |
1 files changed, 46 insertions, 1 deletions
diff --git a/railties/guides/source/nested_model_forms.textile b/railties/guides/source/nested_model_forms.textile index e975b97ea8..4b685b214e 100644 --- a/railties/guides/source/nested_model_forms.textile +++ b/railties/guides/source/nested_model_forms.textile @@ -174,4 +174,49 @@ When this form is posted the Rails parameter parser will construct a hash like t } </ruby> -That’s it. The controller will simply pass this hash on to the model from the +create+ action. The model will then handle building the +address+ association for you and automatically be saved when the parent (+person+) is saved.
\ No newline at end of file +That’s it. The controller will simply pass this hash on to the model from the +create+ action. The model will then handle building the +address+ association for you and automatically save it when the parent (+person+) is saved. + +h5. Nested form for a collection of associated objects + +The form code for an association collection is pretty similar to that of a single associated object: + +<erb> +<% form_for @person do |f| %> + <%= f.text_field :name %> + + <% f.fields_for :projects do |pf| %> + <%= f.text_field :name %> + <% end %> +<% end %> +</erb> + +Which generates: + +<html> +<form action="/people" class="new_person" id="new_person" method="post"> + <input id="person_name" name="person[name]" size="30" type="text" /> + + <input id="person_projects_attributes_0_name" name="person[projects_attributes][0][name]" size="30" type="text" /> + <input id="person_projects_attributes_1_name" name="person[projects_attributes][1][name]" size="30" type="text" /> +</form> +</html> + +As you can see it has generated 2 +project name+ inputs, one for each new +project+ that’s build in the controllers +new+ action. Only this time the +name+ attribute of the input contains a digit as an extra namespace. This will be parsed by the Rails parameter parser as: + +<ruby> +{ + "person" => { + "name" => "Eloy Duran", + "projects_attributes" => { + "0" => { "name" => "Project 1" }, + "1" => { "name" => "Project 2" } + } + } +} +</ruby> + +You can basically see the +projects_attributes+ hash as an array of attribute hashes. One for each model instance. + +NOTE: The reason that +fields_for+ constructed a form which would result in a hash instead of an array is that it won't work for any forms nested deeper than one level deep. + +TIP: You _can_ however pass an array to the writer method generated by +accepts_nested_attributes_for+ if you're using plain Ruby or some other API access. See (TODO) for more info and example.
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