从 Rails 表单构建器获取输入名称

Question

How can I get a string with form input name?

<%= form_with model: @post do |f| %>
  <%= f.text_field :name %>
  <!-- Will produce HTML <input type="text" id="post_name" name="post[name]" value="" /> -->
<% end %>

The question is how can I get the name of input name without generating it? Is this example it should be a string "post[name]"

Answer 1

When you are within a form_with model: @post block you could build the "post[name]" string like this:

"#{dom_class(f.object)}[name]"

See the docs of dom_class

Answer 2

What you could be looking for is the object_name method

f.object_name should return "post"

It will work as well for multiple nested fields_for

<%= form_with model: @team do |team| %>
  <%= team.fields_for :players do |player| %>
  <%# for 1st player: player.object_name #=> "team[players_attributes][0]" %>
<% end %>

What ever you case is, you still have to concatenate your field name between brackets "[field_name]" , and so you can easily construct the right name for your input's field