Setting Up Goto Declaration in Atom

Update (screw this)

I'll leave everything below for someone who loves using Atom and is okay have having partial support for goto functionality. I basically want the following (ST3), but can't achieve it in Atom.

Sublime example

I've tried a million different tweaks and used every package I can find, but I can't get it to work the way it should. If you're a ctags ninja you might have better luck than me. ¯\_(ツ)_/¯

If you've used some sort of goto functionality before, you'll probably feel a little underwhelmed when you fire up Atom for the first time. I've done all the banging my head against the desk for you. Here's how you get it done.

What is goto declaration?

I primarily do my web projects in Rails. So, let's take an example from that framework. Let's say I have a goofy helper:

def site_title(title)

Let's also say that I'm lazy or rushed and I buried this helper in an unknown file. Later, I come across its usage in a view:

<%= content_tag :h1, site_title('this page is awesome') %>

I see that a helper is being called, but I can't remember where it is. Maybe I didn't even write the helper to begin with. You could cmd+shift+f to search for it, but that's cumbersome. In RubyMine you'd be able to cmd+click the helper and it would open the file where the helper is declared and put the cursor on that line. Sublime Text 3 has built-in functionality as well. But, what about Atom?

Not so much.

Configuring Atom

As of this writing, Atom ships with a package called symbols-view. This will give you some keybindings and a Go to Declaration option in your right-click (or cmd+click) menu. However, it won't do a damn thing for you without some configuration.

Symbols-view requires the presence of ctags. I won't get too much into ctags, but they're essentially an index file that maps symbols. You're going to need a way to generate a .tags file for this all to work.

Install the symbol-gen package

In order to generate a .tags file install this package. Once it's installed, you can use cmd+alt+g to generate the .tags file in the root of your project.

If the computer gods are looking down upon you, you'll now be able to use the symbols-view keybindings or context menu commands. It will look something like this:

Goto declaration

Victory! But wait, there's more...

Configure ctags for CSS

Completing the steps above will help you with a bunch of the ruby-specific stuff. However, if you dream of being able to go to the declaration of a CSS class from an .html.erb file you're currently boned. You need to tell ctags to include CSS.

Open up ~/.ctags and add the following:

--regex-css=/^[ \t]*(([A-Za-z0-9_-]+[ \t\n,]+)+)\{/\1/t,tag,tags/
--regex-css=/^[ \t]*#([A-Za-z0-9_-]+)/#\1/i,id,ids/
--regex-css=/^[ \t]*\.([A-Za-z0-9_-]+)/.\1/c,class,classes/

Credit to this post for the ctags snippet. After you add the above and save the file you can generate your .tags file again by using cmd+alt+g. This should now give you some CSS functionality. It can find symbols, but no goto functionality :(