alias_attribute and creating and method with the original attribute name causes a loop
Im trying to dynamically create a method chain in one attribute in my model. By now I have this function:
def create_filtered_attribute(attribute_name)
alias_attribute "#{attribute_name}_without_filter", attribute_name
define_method "#{attribute_name}" do
filter_word开发者_如何学运维s(self.send("#{attribute_name}_without_filter"))
end
end
so I receive a string with the attribute name, alias it for '_without_filter' (alias_method or alias_method_chain fails here, because the attribute isnt there when the class is created), and I create a new method with the attribute name, where I filter its contents.
But somehow, when I call "#{attribute_name}_without_filter" it calls my new method (i think because the alias_attribute some how), and the program goes into a stack loop.
Im trying to rename that attribute, so I can use its name for a method...
Can someone please enlighten me on this.
There is a difference between alias_method
and alias_attribute
. alias_method actually makes a copy of the old method, whereas alias_attribute just defines new methods, which call old ones.
Note, that model.attribute
and model.attribute=
methods in ActiveRecord simply call read_attribute and write_attribute, so you always can access your attribute, even if you override it's getter or setter:
define_method "#{attribute_name}" do
filter_words(self.read_attribute(attribute_name))
end
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