Ruby on Rails - Can I modify the value of an attribute before it is called?
-
05-07-2019 - |
Question
Let's say I have this model named Product with a field named brand. Suppose the values of brand are stored in the format this_is_a_brand. Can I define a method in the model (or anywhere else) that allows me to modify the value of brand before it is called. For example, if I call @product.brand, I want to get This is a Brand, instead of this_is_a_brand.
Solution
I would recommend using the square bracket syntax ([]
and []=
) instead of read_attribute
and write_attribute
. The square bracket syntax is shorter and designed to wrap the protected read/write_attribute methods.
def brand
original = self[:brand]
transform(original)
end
def brand=(b)
self[:brand] = reverse_transform(b)
end
OTHER TIPS
Rather than accessing @attributes directly, you should use read_attribute
and write_attribute
:
def brand
b = read_attribute(:brand)
b && b.transform_in_some_way
end
def brand=(b)
b && b.transform_in_some_way
write_attribute(:brand, b)
end
In your model you can override the method call brand
.
def brand
#code to modify the value that is stored in brand
return modified_brand
end
This will allow it to be stored as this_is_a_brand. But, it will be returned as "this is a brand".