Add a CSS class to <%= f.submit %>

Question

<%= f.submit 'name of button here', :class => 'submit_class_name_here' %>

This should do. If you're getting an error, chances are that you're not supplying the name.

Alternatively, you can style the button without a class:

form#form_id_here input[type=submit]

Try that, as well.

You can add a class declaration to the submit button of a form by doing the following:

<%= f.submit class: 'btn btn-default' %> <-- Note: there is no comma!

If you are altering a _form.html.erb partial of a scaffold and you want to keep the dynamic change of the button name between controller actions, DO NOT specify a name 'name'.

Without specifying a name and depending on the action the form is rendered the button will get the .class = "btn btn-default" (Bootstrap class)(or whatever .class you specify) with the following names:

• Update model_name

• Create model_name
  (where model_name the name of the scaffold's model)

Rails 4 and Bootstrap 3 "primary" button

<%= f.submit nil, :class => 'btn btn-primary' %>

Yields something like:

As Srdjan Pejic says, you can use

<%= f.submit 'name', :class => 'button' %>

or the new syntax which would be:

<%= f.submit 'name', class: 'button' %>

Solution When Using form_with helper

<%= f.submit "Submit", class: 'btn btn-primary' %>

By default, Rails 4 uses the 'value' attribute to control the visible button text, so to keep the markup clean I would use

<%= f.submit :value => "Visible Button Text", :class => 'class_name' %>