Rails View DRYness - Do you set variables in the view or just make clean methods?

I have a view in which I have the same link 3 times (actual view is large):

%h1= link_to "Title", model_path(@model, :class => "lightbox")
= link_to "Check it out", model_path(@model, :class => "lightbox")
%footer= link_to "Last time", model_path(@model, :class => "lightbox")

That model_path(@model, :class => "lightbox") call, though fairly clean, can be made even leaner wrapping it in this (maybe you had some more options, so doing this was worthwhile):

def popup_model_path(model)
  model_path(model, :class => "lightbox")
end

My question is, I am having to recalculate that path 3 times in a view. What is the preferred way of a) DRYing this up and b) optimizing performance?

I think setting variables at the top of the view might be a good idea here:

- path = model_path(@model, 开发者_如何学编程:class => "lightbox")
-# ... rest of view

It's almost like mustache in the end then. What are your thoughts?

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I think using variables in the view is a good idea here. Since these method calls are exactly the same.

The solution as proposed by Matt i prefer in some cases, but not in this case, because i find it confusing: the fact that it is cached in the method is not clear, and if i want to see two different models in one page i still get the first cached link for both models.

So in this case I would choose the somewhat more explicit approach and assign it to a variable in the view.

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I really hate putting variables in the view. I would change your helper to

def popup_model_path(model)
  @model_path ||= {}
  @model_path[model] ||= model_path(model, :class => "lightbox")
end

to "memoize" it, and just keep the three function calls.

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This seems like a possible case of premature optimization. Making a function like popup_model_path is a fantastically DRY idea. Especially if that bit of code, however terse it may be originally, is going to be used frequently across multiple views. However, worrying about the performance impact of calculating the path 3 times in one view is, in my opinion, needless. Unless we're talking about something that is going to be used dozens or hundreds of times per view, and you're expecting many many simultaneous users, and the app is running on a shared server or something I really don't see what you have currently having any perceptible impact on performance.

As a general rule, I do my best to avoid variables in my view code. They make it harder to read and with a few exceptions (such as variables directly related to loops that display stuff like lists) I feel they kinda go against the whole MVC concept as I understand it.

I think above all else you should strive for code that is easily readable, understandable, and maintainable; both for yourself and others not previously familiar with your project. popup_model_path as you have it now is simple enough to where anyone who knows Rails can follow what you're doing. I don't see any need to make it any more complicated than that since it's not terribly repetitive. I wish I could find this excellent blog post I remember reading a while ago that made the point that DRYing up your code is great, but it has its limits, and like all great things the law of diminishing returns eventually kicks in.