alias_method_chain

alias_method_chain

alias_method A, B 有點就是 B 把function copy 一份到B

Encapsulates the common pattern of:<br /> alias_method :foo_without_feature, :foo<br /> alias_method :foo, :foo_with_feature<br />
這就像是foo 沒改feature之前 copy 一份 所以叫做 foo_without_feature
然後弄了個function 叫做foo_with_feature 然後蓋掉 foo
之後叫foo 就是有feature的 foo_with_feature

With this, you simply do:<br /> alias_method_chain :foo, :feature<br />
And both aliases are set up for you.

Query and bang methods (foo?, foo!) keep the same punctuation:<br /> alias_method_chain :foo?, :feature<br />
is equivalent to<br /> alias_method :foo_without_feature?, :foo?<br /> alias_method :foo?, :foo_with_feature?<br />
so you can safely chain foo, foo?, and foo! with the same feature.