Displaying and selecting from a HABTM

Question

Currently I have a Category and Post model, joined by a HABTM relationship.

Posts belong to multiple categories and have many attributes.

Categories just have a Name Property.

How do I create a multi-select form in my Posts _form.html.erb so I can select which categories I want the post to be assigned to?

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score 1 · Accepted Answer · answered Mar 27 '15 at 19:07

<%= form_for @post do |f| %>
  <div>
    <%= f.label :category_ids, "Categories" %><br />
    <%= f.collection_select :category_ids, Category.order(:name), :id, :name, {}, {multiple: true} %>
  </div>

  <div>
    <%= f.submit 'Submit' %>
  </div>
<% end %>

score 0 · Answer 2 · answered Mar 27 '15 at 19:02

Try using select and collection. You may have to change the collection, not sure exactly what Category options you want to be able to choose from. Something like this:

<%= f.input :post, as: :select, collection: Category.posts, include_blank:false %>

Or checkout out the collection_select form helper method http://api.rubyonrails.org/classes/ActionView/Helpers/FormOptionsHelper.html#method-i-collection_select

Displaying and selecting from a HABTM

2 Answers2