I have a model connecting to a Postgres db.
class Person < ApplicationRecord
def say_id
"#{name} has id: #{id}"
end
end
I have some attributes id,name,email as well as the method above: say_id that can be accessed via:
person = Person.new
person.id => 1
person.say_id => "John has id: 1"
I would like to have the method 'say_id' listed as an attribute as well, now when running person.attributes, I'm only seeing: id, name, email
How can I have my method included as a listable information in full, as with person.attributes but which will include my method? A usecase would be for lazily just laying out all these fields in a table of the Person-object.
In Rails 5+ you can use the attributes api to create attributes that are not backed by a database column:
class Person < ApplicationRecord
attribute :foo
end
irb(main):002:0> Person.new.attributes
=> {"id"=>nil, "email"=>nil, "name"=>nil, "created_at"=>nil, "updated_at"=>nil, "foo"=>nil}
Unlike if you used attr_accessor
these actually behave very much like database backed attributes.
You can then override the getter method if you wanted to:
class Person < ApplicationRecord
attribute :foo
def foo
"foo is #{super}"
end
end
irb(main):005:0> Person.new(foo: 'bar').foo
=> "foo is bar"
But for whatever you're doing its still not the right answer. You can get a list of the methods of an class by calling .instance_methods
on a class:
irb(main):007:0> Person.instance_methods(false)
=> [:foo]
Passing false
filters out inherited methods.
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