Can split form_for into two parts?

Rails
1

Rails 3.1.3

Is it possible to split form_for block into two parts?

More specifically, I want to create and save a model after filling
required fields.
But some of the fields are not required and unnecessary for the model.

<%= form_for(@foo) do |f| %>
f.field A
<% end %>

and form_tag updates the following select fields in form_for block with
JavaScript

<%= form_tag do %>
…
<% end %>

<%= form_for(@foo) do |f| %>
f.field B
<% end %>

Apparently if I hit the save button, it needs to save both field A and
B.

Thanks in advance.

soichi

2

On Nov 15, 2012, at 1:15 AM, Soichi I. wrote:

<% end %>
<% end %>

Apparently if I hit the save button, it needs to save both field A and
B.

Are you sure they need to be two separate forms? If your view pseudocode
is accurate, these would both post to the same controller method. You
can simply hide the non-essential fields with JavaScript, and show them
conditionally. If the field is submitted empty, that would not change
your model, right? Likewise if there’s a default value, that would also
be present in the view, just not shown to the visitor.

Show Options

f.field A

f.field B, :class => ‘optional’

Walter

3

Show Options

f.field A

f.field B, :class => ‘optional’

Walter

Oh, thanks. Simpler than I thought.

soichi

4

Is there anyway to manipulate form_tag from controllers?

Like, in order to edit, _form.html.erb must to be filled with the values
for the model.
At the same time, there are some checkbox or radio buttons related to
the form, but they are not needed for the model directly.

I want to choose the values and fill those form_tag fields as well when
users click edit action.

soichi

5

I think what you are looking for is fields_for. This let’s you put data
in
a different part the params hash. This allows you to either get those
fields out of the fields for a given model or allows you to update more
than one model or a nest model cleanly.

While the Javascript example is clever, I would caution against as it
breaks your MVC design pattern putting logic in your view. Doing inline
programming as a matter of course will leave the application difficult
to
maintain over time.

For this case, the Javascript does not sound necessary.

6

On 16 November 2012 07:37, Soichi I. [email protected] wrote:

Is there anyway to manipulate form_tag from controllers?

Like, in order to edit, _form.html.erb must to be filled with the values
for the model.
At the same time, there are some checkbox or radio buttons related to
the form, but they are not needed for the model directly.

I want to choose the values and fill those form_tag fields as well when
users click edit action.

You can put data in @variables in the controller and then access those
in the view to put whatever you like in the fields.

Colin