Creating Helper Methods To Be Used Within Model

rubyonrails-talk
1

Where do people suggest we create helper methods that are going to be used within the model to do things like string manipulation.

For instance:

Tag.name.make_url_friendly

Does anyone have an examples where I would put this and how I would define it? It would be greatly appreciated.

Your Friend,

2

You have two options really:

1) Create some custom modules for your functionality then include them in your model.

module MyStringUtilities   def make_url_friendly(string)   end end

class Tag < AR::Base   include MyStringUtilities end

2) Write direct extensions to built-in classes

class String   def make_url_friendly   end end

The above would let you use the syntax you use in your post (Tag.name.make_url_friendly). Both have their place. Choose whichever you feel more comfortable with.

3

Perfect! I put class String.... end at the end of my application_helper.rb. I am not sure if tha tis the best place to put it but right now it makes the most sense. Any better ideas?

4

Yeah, stick it in its own file in lib, then require it in environment.rb.

5

only. For something like this, you should put it in the Tag model class (app/models/tag.rb)

John Kopanas wrote:

6

Good point. Problem is that I use this method in all three... models, views and controllers. :slight_smile:

So putting it in the lib directory might be the best option. But then again their might be even better ones out their :-). People?

7

I think this is merely a mix up of terminology. The word "helper" in the Rails sense derives from the ViewHelper pattern. I believe the OP was simply referring to common utility methods used throughout his code.

8

I would say you should prefer the first method of using modules unless there is a very strong case for extending builtin objects. I think going for a module first, and then seeing just how useful certain methods are before going to a builtin. Extending String is a very powerful and useful thing, but it can also be dangerous as it clutters the namespace and could result in conflicts in the future (ex: you write String#to_url, and two months from now Rails includes a conflicting version).

my 2 cents...

- Rob

9

There is one implementation option that is surprisingly void from this conversation: plugins.

One of the reasons plugins exist is a *better* form of "throw some shit in /lib and require it"

This smells like a good case for an extension of AR::Base, perhaps. Look at plugins. They are easy and grand and way better than the hacky lib approach.

10

Seth, I fail to see how putting utility, yet project-specific, library code in lib (where it belongs) is "hacky". Plugins would be completely overkill for this.

11

hmmm... plugins does sound really sexy if I look longer term. Very good idea. Might sound overfill for one small method but surely it will grow! :slight_smile: