Rails core - Jul 2006 - plugins playing nice together

Hello,

I have a question about plugins playing nice together when you have
more than one plugin that attempts to override the same rails method.

In my case I have written a plugin that provides it''s own
form_remote_tag implementation, but I also have another plugin
installed that does the same thing.  My plugin version does not work
though as any form_remote_tag calls are instead being redirected to
version in the other plugin (most likely due to being loaded after my
plugin).

Is there some known way to prevent such issues or to at least warn of
them?  I can see problems such as this becoming more common as people
install more and more plugins.

Thanks for any insight,
Andrew

On 2006-07-21, at 20:53 , Andrew Kaspick wrote:
> ... My plugin version does not work
> though as any form_remote_tag calls are instead being redirected to
> version in the other plugin (most likely due to being loaded after my
> plugin).
>
> Is there some known way to prevent such issues or to at least warn of
> them?
You can use alias_method_chain to wrap the original method call, but  
that relies on both plugins using it, and if you''re not going to use  
the original call, well, it''s just counter intuivive. Here''s
an example

   MyPlugin::MyModule
     def self.included base
       base.alias_method_chain :some_method, :superfun_feature
     end

     def some_method_with_superfun_feature
       do_stuff
       some_method_without_superfun_feature
     end
   end
end

class WhateverIWantToExtend
   include MyPlugin::MyModule
end

You can also hook up to the method_defined ruby callback, and issue a  
warning whenever a method from your plugin is redefined, or even  
alias back your method over the new one (evil).

   class ThingIModified
     def self.method_added m
       return unless m == :do_something
       return unless instance_method(m) != instance_method 
(:do_something_plugin_version)
       warn "do_something redefinition attempt. overriding"
       alias do_something do_something_plugin_version
     end

     def do_something_plugin_version; 1 end
     alias do_something do_something_plugin_version
   end

   t = ThingIModified.new

   class ThingIModified
     def do_something
       2
     end
   end

   t.do_something

Quick corrections:
>   MyPlugin::MyModule
that would be:

   module MyPlugin::MyModule
> You can also hook up to the method_defined ruby callback
I meant method_added, as seen in the example code (which is tested,  
meaning you can run it in irb and see it working)

Thanks for the info, that helps a lot.

On 7/21/06, Caio Chassot <lists@v2studio.com>
wrote:
> Quick corrections:
>
> >   MyPlugin::MyModule
>
> that would be:
>
>    module MyPlugin::MyModule
>
> > You can also hook up to the method_defined ruby callback
>
> I meant method_added, as seen in the example code (which is tested,
> meaning you can run it in irb and see it working)
>
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