Adding CSS styles to a form_tag in Rails 3

I have a Rails app where I am using custom stylesheets that have no effect on the <form> tags generated by the Rails form_tag helper. Can someone point me to so开发者_StackOverflow中文版me code or an example that shows how to add CSS styles to a form_tag?

<% form_tag {:controller => 'my_controller', :action => 'my_action'}, :id => 'my_id' do %>

in .css file

#my_id {
 /* your style */
}

With the form_for helper, the first argument you pass is used exclusively by the url_for helper to determine what URL to submit the form to. Hash-style named arguments are treated as a single argument (a hash) by Ruby, so if you pass a set of options as your first argument (e.g. form_tag(controller: 'my_controller', action: 'show')), any additional options you include (like :method or :class) will be treated as options to url_for instead of to form_for, which isn't what you want.

To fix this, you can explicitly pass a hash as the first argument to form_tag, and put your other options (such as the class attribute, which is probably what you'll want to use for styling) outside of that hash, like so:

<% form_tag {controller: 'my_controller', action: 'show'}, class: 'main-form' do %>
  <!-- Form content here -->
<% end %>

After that, you can use css to style your form as you would with any other element:

.main-form {
  // Style rules here
}

For more information on the options form_for accepts, see the docs for form_for and url_for.

Few ways you can do this:

form {
  color: red;
}

This will grab ALL forms and style them.

#id {
  color: red;
}

This will grab the forms that match the ID and style them.

.class {
  color: red;
}

This will grab the forms that match the class and style them.