Question: I have form like this: 

```
<%= simple_form_for @category do |f| %>
  <%= f.input :name %>
  <%= f.input :description %>
  <%= f.input :parent_id, collection: @board.subtree, include_blank: false %>
  <%= f.button :submit %>
<% end %>

```

`@category` is instance of `Board` so this `:submit` tries to run `create` action from `BoardsController`. Instead of it, I'd like to run `create` action from `CategoriesController`. 

How can I do this?

Answer: 
Just add the `url` option. 

```
<%= simple_form_for @category, url: category_path(@category) do |f| %>

```
This might help:

<https://stackoverflow.com/a/7136142/2128691>

so yours would look like: 

```
<%= simple_form_for @category, :url => category_path, do |f| %>
 ...
<% end

```