Meta programming problem

rubyonrails-talk
1

Hi,

i've wrote the following code module TeamScore   class Filter     ALLOWED_RESOURCES = [:game]

    # convert <game:4 title> into markdown link to game re     # use game title as link name     # "Google":http://google.com.

2

Hi,

i've wrote the following code module TeamScore   class Filter     ALLOWED_RESOURCES = [:game]

    # convert <game:4 title> into markdown link to game re     # use game title as link name     # "Google":http://google.com.     #     def self.filter(str)       str.gsub(/<([a-z]+):(\d+)>/) do |match|         create_link_for($1.to_sym,$2, match)       end     end

    def self.create_link_for(resource_type, id, match)       raise "Macro #{match} not allowed" unless ALLOWED_RESOURCES.include?(resource_type.to_sym)       case resource_type         when :game           model = Game         when :article           model = Article       end       object = model.send("find", id)

"\"#{object.name}\":www.teamscore.org/#{object.class.name.pluralize.downcase}/#{object.id}"     end   end end

How i can dry case when block.

Remove it altogether :wink: see below.

My idea is to send a find message to model coresponding the resource_type argument but resource_type is a string (previously extracted from regexp) and I can't use ressource_type.send(....) or send("#{ressource_type.classify}.find", id) the 2 stament raise an error (NoMethodError: undefined method `Game' for TeamScore::Filter:Class)

You don't need the send here. Send without an object tries to execute send on the current scope, which would be TeamScore::Filter. In this case, you are trying to execute self.Game.find(id), which is of course not valid (unless you happened to have a constant called Game defined on the class...).

Try resource_type.classify.find(id).

resource_type.classify will simply return the class (Game or Article), which you can happily call any methods on.

Cheers, Max

3

Max Muermann a écrit :

Remove it altogether :wink: see below.

> My idea is to send a find message to model coresponding the > resource_type argument but resource_type is a string (previously > extracted from regexp) and I can't use ressource_type.send(....) > or send("#{ressource_type.classify}.find", id) the 2 stament raise an > error (NoMethodError: undefined method `Game' for > TeamScore::Filter:Class)

You don't need the send here. Send without an object tries to execute send on the current scope, which would be TeamScore::Filter. In this case, you are trying to execute self.Game.find(id), which is of course not valid (unless you happened to have a constant called Game defined on the class...).

Try resource_type.classify.find(id).

resource_type.classify will simply return the class (Game or Article), which you can happily call any methods on.

Cheers, Max

Thanks,

I've try it but this doesn't work. I've got an LocalJumpError or something like this. I think it try to invoke find on a String not on the Game or Article. The classify method just retunr a string in my mind.

4

Guillaume :

> You don't need the send here. Send without an object tries to execute > send on the current scope, which would be TeamScore::Filter. In this > case, you are trying to execute self.Game.find(id), which is of course > not valid (unless you happened to have a constant called Game defined > on the class...). > > Try resource_type.classify.find(id). > > resource_type.classify will simply return the class (Game or Article), > which you can happily call any methods on.

Thanks,

I've try it but this doesn't work. I've got an LocalJumpError or something like this. I think it try to invoke find on a String not on the Game or Article. The classify method just retunr a string in my mind.

Try :

  resource_type.classify.constantize.find(id)

    -- Jean-François.

5

This work great.

Thank a lot.

Jean-François a écrit :