How get integer value from a enum in Rails?

Question

I have a enum in my Model that corresponds to column in the database.

The enum looks like:

  enum sale_info: { plan_1: 1, plan_2: 2, plan_3: 3, plan_4: 4, plan_5: 5 }

How can I get the integer value?

I've tried

Model.sale_info.to_i

But this only returns 0.

Solution 1

You can get the integer values for an enum from the class the enum is on:

Model.sale_infos # Pluralized version of the enum attribute name

That returns a hash like:

{ "plan_1" => 1, "plan_2" => 2 ... }

You can then use the sale_info value from an instance of the Model class to access the integer value for that instance:

my_model = Model.find(123)
Model.sale_infos[my_model.sale_info] # Returns the integer value

Solution 2

You can get the integer like so:

my_model = Model.find(123)
my_model[:sale_info] # Returns the integer value

Update for rails 5

For rails 5 the above method now returns the string value :(

The best method I can see for now is:

my_model.sale_info_before_type_cast

Shadwell's answer also continues to work for rails 5.

Solution 3

Rails < 5

Another way would be to use read_attribute():

model = Model.find(123)
model.read_attribute('sale_info')

Rails >= 5

You can use read_attribute_before_type_cast

model.read_attribute_before_type_cast(:sale_info)
=> 1

Solution 4

I wrote a method in my Model to achieve the same in my Rails 5.1 app.

Catering for your case, add this into your Model and call it on the object when needed

def numeric_sale_info
  self.class.sale_infos[sale_info]
end

Solution 5

My short answer is Model.sale_infos[:plan_2] in case if you want to get value of plan_2

View more solutions

Comments

[etlds]

It is because 'enum' will create a method sale_info for your model, use [:sale_info] to get the property value instead of return from sale_info method.

[Tim Smith]

Note that this method does not work if the model has not been saved. The sale_info_before_type_cast value (and my_model[:sale_info]) is still a string if it my_model.sale_info has been assigned a string without a subsequent save.

[ArashM]

@GrantBirchmeier Updated the answer. You can use read_attribute_before_type_cast.

[zw963]

Before Rails 5, model.read_attribute('sale_info') equal to model[:sale_info]

[dazonic]

I like this approach. When using before_type_cast, it’ll return a string if you’re on an unsaved record you’ve initialised like Post.new status: :unapproved, but an integer if it’s persisted.