Question

This question has answered the question for a single column but how do you do it for multiple columns? I’ve got three columns (website, fb, twitter) that I want to prefix with http in case users don’t input them in the form.

I tried this but it doesn’t work:

before_save :sanitize_links

private

def sanitize_links
  website = self.website
  facebook = self.facebook
  twitter = self.twitter
  links = [website, facebook, twitter]
  links.each do |link|
    unless link.include?("http://") || link.include?("https://")
      link = "http://" + link
    end
  end
end

---

Update

I’ve tried the suggestion by KL-7 but unfortunately hit a little snag. How do I use the output of the array with before_save? I’ve tried the code below but it doesn’t work.

before_save :sanitize_links

private

def sanitize_links
  links = ["website", "facebook", "twitter"]
  links.map! { |link| self.link =~ %r{\Ahttps?://} ? self.link : "http://" + self.link }
end

---

Update 2

I gave up. I’ll just repeat it three times:

before_save :sanitize_links

private

def sanitize_links # prefix user-submitted links with http:// if missing
  self.website =~ %r{\Ahttps?://} ? self.website : self.website = "http://" + self.website
  self.facebook =~ %r{\Ahttps?://} ? self.facebook : self.facebook = "http://" + self.facebook
  self.twitter =~ %r{\Ahttps?://} ? self.twitter : self.twitter = "http://" + self.twitter
end

Answer 1

The problem is that

link = "http://" + link

in your code assigns a new value to the link variable withing the block, but doesn’t change the corresponding element of the list.

To alter elements of the list in-place you can use Array#map!:

links.map! do |link|
  link.include?("http://") || link.include?("https://") ? link : "http://" + link
end

Another thing I’m a bit worried about is that include? will return true even if the given substring (e.g., 'http://' occurs somewhere in the middle of your string and not necessarily at the beginning. I’d rather use a regexp for that task:

links.map! { |link| link =~ %r{\Ahttps?://} ? link : "http://" + link }

Update

If link is an attribute of your model, then you should at least store it as an attribute and not as a local links variable:

self.links = links.map { |link| link =~ %r{\Ahttps?://} ? link : "http://" + link }