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PORuby: Dynamically defining class methods in a module
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2013-07-11T17:54:31.323
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I'm having trouble dynamically defining class methods within a module. See code below. I get a <code>NameError: undefined local variable or method</code> when trying to reference another class method in the module. Seems like this might be a scope or context issue, but I've not been able to figure it out so far. <pre><code>module Bar def self.included(base) base.extend ClassMethods end module ClassMethods def fruits ["apple", "orange", "banana"] end def example_function(string) string.upcase end fruits.each do |fruit| method_name = fruit.to_sym define_method(method_name) { example_function(fruit) } end end end class Foo include Bar end puts Foo.apple puts Foo.orange puts Foo.banana </code></pre> I want to be able to call: <pre><code>puts Foo.apple => "APPLE" puts Foo.orange => "ORANGE" puts Foo.banana => "BANANA" </code></pre> Currently when I try any of these I get the following error: <code>NameError: undefined local variable or method 'fruits' for Bar::ClassMethods:Module</code> Additionally, class methods in Bar::ClassMethods should be available to Foo, so I should be able to call: <pre><code>puts Foo.fruits => ["apple", "orange", "banana"] </code></pre> Requirements: <ol> <li>All code is within a single module.</li> <li>The module allows mixing both instance and class methods (article below).</li> <li>The target methods are dynamically defined.</li> </ol> Read "Include vs Extend in Ruby" (esp. section titled "A Common Idiom") <a href="http://www.railstips.org/blog/archives/2009/05/15/include-vs-extend-in-ruby/" rel="nofollow">http://www.railstips.org/blog/archives/2009/05/15/include-vs-extend-in-ruby/</a> Help with this is greatly appreciated!
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<ruby><metaprogramming>
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Ruby: Dynamically defining class methods in a module
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