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Ruby

Marc Burt
Marc Burt
9,828 Points
Posted by Marc Burt
Marc Burt
9,828 Points

Need a bit of .gsub code explained

Here is some code: 

def to_param
        "#{id}-#{title.gsub(/[^a-z1-9]+/i, '-')}"
    end

I know that this appends the content of 'title' to the URL of my routes after the id (I've left the id in since it prevents a lot of other problems and I don't mind it for this project).

The gsub method substitutes non alphanumeric characters with a dash to make them URL friendly, but I'm not sure how that code is written..

I can't find good documentation of it but I think either the ^ before the a the + or the i probably translates to everything except the listed characters. Does anyone know which and what the other characters do?

1 Answer

Naomi Freeman
STAFF
Naomi Freeman
Treehouse Guest Teacher
Naomi Freeman
Naomi Freeman
Treehouse Guest Teacher

The stuff after .gsub is regex (regular expressions):

http://rubular.com/

This is also an excellent resource if you're willing to work through it: http://www.regular-expressions.info/tutorial.html

This one helped a friend of mine through an interview: http://regexone.com/

Does the code you posted work?

Marc Burt
Marc Burt
9,828 Points
Marc Burt
Marc Burt
9,828 Points

Fantastic, thank you.

So the ^ means anything except those characters, the + means include multiples and the i means case insensitive.

Yes the code works perfectly.