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Define class methods with Modularity traits

There are two ways to define a class method from a Modularity trait. Note that the usual caveats regarding class method visibility apply.

Using define_method

The recommended way is to define a method on your module’s singleton class:

# ruby 1.9+ module SomeTrait as_trait do define_singleton_method :foo do # ... end end end # ruby <1.9 module SomeTrait as_trait do singleton_class.send :define_method, :foo do # ... end end end

Using def (has caveats!)

Alternatively, you can def the method on self:

module SomeTrait as_trait do def self.foo # ... end end end

This is quite concise and results in faster methods than using define_method. However, you cannot use it with parametrized traits.

The following will fail:

module SomeTrait as_trait do |name| def self.foo puts name # will raise an error because the variable 'name' is not bound to the method body end end end
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Author of this card:

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Henning Koch
Last edit:
about 1 month ago
by Besprechungs-PC
Keywords:
static, method
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Posted by Henning Koch to makandropedia