Rubymotion: NoMethodError to add a method

Question

I added an extra method to the String class. I want to use this method later, but I don't have a method error.

class String def as_file_full_path NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, true) [0].stringByAppendingPathComponent(self) end end 

When I try to do the following in REPL, it works:

  (main)> "image.jpg".as_full_path => "/Users/user/Library/Application Support/iPhone Simulator/6.1/Applications/30D186A9-B1C7-4377-AE91-0D14BD3B4A6D/Documents/image.jpg" 

But when I call the method in the model class, it no longer works:

  (main)> w = Word.first => #<Word:0x94d7df0> (main)> w.filename => "2C86A58A-A92A-4A0F-B26C-0F5F583E142C.caf" (main)> w.filename.class => String (main)> w.filename.as_full_path 2013-02-28 09:17:55.935 project[74283:c07] undefined method `as_full_path' for "2C86A58A-A92A-4A0F-B26C-0F5F583E142C.caf":String (NoMethodError) => NoMethodError: undefined method `as_full_path' for "2C86A58A-A92A-4A0F-B26C-0F5F583E142C.caf":String 

The model is implemented using NanoStore :: Model.

Edit:

When I clone the String returned by the model, the added method is present.

 w.filename.dup.as_full_path => "/Users/user/Library/Application Support/iPhone Simulator/6.1/Applications/30D186A9-B1C7-4377-AE91-0D14BD3B4A6D/Documents/2C86A58A-A92A-4A0F-B26C-0F5F583E142C.caf" 

Answer 1

The problem is solved! For some reason, the extension of the String class does not always work. I think that for some reason NanoStore does not return “real” ruby ​​strings. Solved it by replacing "String" with "NSString" like this:

 class NSString def as_file_full_path NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, true) [0].stringByAppendingPathComponent(self) end end