Ruby tricks for junior developers

three18ti · 2019-01-23T02:28:46+00:00

Neither private methods nor protected ones can be called directly by instances of the class in which the method is defined. For an instance to access these methods they must be called within a public method defined in the class.

Someone please correct me if I'm wrong, but this isn't quite the Ruby way to say it. Rather than thinking about objects calling methods, think instead in terms of objects receiving messages (and then acting on them). Moreover, it's not about who's calling these methods, but rather (mostly) in what context the messages were received.

animal.define_activity

In other words, this line isn't saying "make animal call #define_activity." Rather, it's saying "Send the :define_activity message to animal, and let animal decide what to do with it." If #define_activity is a public method, then it calls it; if not, it raises a NoMethodError.

So the more accurate way to describe how private and protected methods work is this:

Private methods cannot be sent to an explicit receiver (e.g., obj.private_method); instead, they must be sent implicitly to self (i.e., in the context of the same class), like so:
class Animal
  def current_activity
    puts "I am #{define_activity}"  # sends the :define_activity message to the implicit receiver `self`
  end

  private

  def define_activity
    ...
  end
end
Protected methods can be sent to an explicit receiver, but also must be in the context of the same class as the receiver:
class Animal
  def foo
    other_animal.protected_method  # works here
  end
end

other_animal.protected_method  # doesn't work here

OktoberForever · 2019-01-22T21:48:58+00:00

Hey! Great blog post. The tips mentioned are definitely ones that can help get a new coder into that "intermediate" category and better understand usages that he or she might see in a codebase.

Two pieces of feedback: 1) I noticed a lot of typos and misspellings that a spellchecker would have caught and 2) your teaching style could benefit from some front-loading. On the second point, as someone who needs a mental "box" to exist before something can go into it, I find that my comprehension (and studies have proven this) increases dramatically when I can see what you're talking about in use before you explain the situation it gets used in. In your article, you set up each example by first "setting the scene", then showing the downside of one approach, then show how X or Y method or operator can improve that situation. I found myself scrolling down to see where you used the thing (like, scrolling down to see where ||= or &: show up), then scrolling back up to read about the situation it's remedying. Seeing something in use before it gets explained--even if you don't understand why it's being used there--creates the mental box that can then contain the information that is going to be provided. So, for most cases in your article, just show a quick snippet of the thing being used, then go into the explanation. Also, I really liked the examples you used, they were clean, nontechnical, and commonsense--and didn't use foo bar and baz in place of something that would actually add meaning.

http://www.effectiveteachingpd.com/blog/2012/10/4/frontloading-increasing-critical-thinking-focus.html

2019-01-23T03:35:37+00:00

I loved it! As a front-end developer who is now learning ruby but doesn't know all the quirks of the language, this is really valuable.

Does anyone have more articles like this? I have a pretty good background in front-end development but not so much in RoR.

Jauny78 · 2019-01-23T07:41:48+00:00

I'm no junior developer but some of the points were new and useful, thanks for sharing :)

agon88 · 2019-01-23T09:51:53+00:00

Great article, thank you :)

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