Saving to an enum field in Rails 4.1.1 - ruby-on-rails

Question

I am trying to make use of the enum feature that has been added to Rails. I had been waiting for this for quite some time.
Here is how I set it up:
Product model:
enum category: [:t_shirt, :hoodie, :jacket]
Product controller:
def create
#product = Product.new(product_params)
if #product.save
redirect_to #product, notice: 'Product was successfully created.' }
else
render :new
end
end
def product_params
params.require(:product).permit(:title, :description, :category, :price)
end
New form
<%= form_for(#product) do |f| %>
<div class="field">
<%= f.label :title %><br>
<%= f.text_field :title %>
</div>
<div class="field">
<%= f.label :description %><br>
<%= f.text_area :description %>
</div>
<div class="field">
<%= f.label :price %><br>
<%= f.text_field :price %>
</div>
<div class="field">
<%= f.label :category %><br>
<%= f.select :category, Product.categories, include_blank: "Select a category" %>
</div>
<div class="actions">
<%= f.submit %>
</div>
<% end %>
This correctly populates the drop-down field in my form with the values of the different enum options which I have defined in the model.
However, when I submit the form having selected one of the categories from the drop-down, it gives me an error:
'0' is not a valid category
Even though my category field is an integer field and '0' is the correct integer associated with the category I selected in my form.
It also highlights the following line from the create method in my Product controller as the place where the error occured:
#product = Product.new(product_params)
I am completely confused as to why this is happening. Would really appreciate some help.
Thank you.

Answer 1

Instead:
<%= f.select :category, Product.categories, include_blank: "Select a category" %>
Try:
<%= f.select :category, Product.categories.keys, include_blank: "Select a category" %>
Explain:
In Product.categories hash {"t_shirt"=>0, "hoodie"=>1, "jacket"=>2} but in Product.categories.keys array what you need ["t_shirt", "hoodie", "jacket"] for select helper.