Add :custom_vars option

[yonda]

Hello!

In the case of using analytics_init method, if you add additional events by add_events option, it is set after that _trackPageview request.

However, for example, as is described in the Google Analytics Documents, we need to set "_trackPageview()" request after setting a custom variable.

In certain cases this might not be possible, 
and you will need to set another _trackPageview() request after setting a custom variable.

(In my applications, _setCustomVar option has not been reflected in the Google Analytics.)

So, I changed the order in which additional events setting.
After change the order, _setCustomVar option has been reflected in the Google Analytics.

What do you think?

Thanks!

[paracycle]

Hi there, we recently ran into this issue as well. It seems both _setCustomVar and _setAllowLinker need to be set before the _trackPageview is generated. So more fine-grained control over how the additional events are processed would be great.

@bgarret Do you have any intentions to accept this pull request and make a release? Do you need any help maintaining the library? Can I help at all?

[bgarret]

@yonda, @paracycle,

I wont merge this as-is because (as @paracycle said) some events need to bet set before and some need to be set after _trackPageView. I'm really picky about backwards compatibility and this PR is likely to break a whole lot of scenarios.

A better solution in this case would be to add a new option (say :before_events, I'm not really sure about this name but it's the first one that popped into my mind) for those events that have to be before the page track.

Regarding the maintenance of the library, I have indeed not touched it for a long long time. I'm not using Rails anymore and I don't really follow the developments of Google Analytics. If you want to lend a hand, I have given you full access to the repo. For the releases, I'll need a rubygems username to be able to add you as an owner.

Thanks for the patience.

[paracycle]

@bgarret Thank you, I will start working on the current issues and make a release. My rubygems username is "ufuk".

@yonda Could you update your pull-request so that before events and after events are properly accounted for in backwards compatible manner? If you can't, please let me know, so that I can start working on it myself. Thanks.

[bgarret]

@paracycle Done, you should be able to push releases on rubygems.

I'm using the following (rough) release process :

• Increase the version number in lib/google-analytics/version.rb
• Update the changelog
• Commit
• Run rake release

I'm not particularly attached to the process but I find it simple and efficient. Feel free to make changes as you see fit.

[yonda]

@paracycle I will be able to update my PR in a few days so that before events and after events are properly accounted for in backwards compatible manner. Please wait until this PR is merged if possible.

@bgarret Thank you, my rubygems username is "yonda". Can you add to the owner ?

[paracycle]

@yonda Sure, I'll be waiting on an update from you.

[bgarret]

@yonda I've added you as an owner on rubygems and a collaborator on github. Let me know if I can do anything.

[yonda]

@paracycle @bgarret
In this case, it seems (as @paracycle said) to need to be set before the _trackPageView event is only _setCustomVar .
So, in the PR, I don't add a new option for this issue, I'll modify to set _setCustomVar before _trackPageview like _setAllowLinker.

What do you think? I am glad if I get your advice.

[paracycle]

@yonda I guess it would be best to just turn this PR into a change that adds a :custom_vars option addition, instead of a full reorder of parameters. Keep in mind that users of the library might want to set multiple custom variables.

This is what I have in mind:

# application.html.erb
...
    <%= analytics_init custom_vars: [
                  GA::Events::SetCustomVar.new(1, 'test_group', 'black', 1),
                  GA::Events::SetCustomVar.new(2, 'cohort', '2014-02', 1)
                ]
    %>
...

# lib/google-analytics/rails/view_helpers.rb
...
       events.unshift GA::Events::TrackPageview.new(options[:page])

       (options[:custom_vars] || []).each do |custom_var|
         events.unshift custom_var
       end
...

What do you think?

[bgarret]

@paracycle 👍 for this, I like the fact that it preserves the GA semantics and does not force the implementer to guess whether the call should go before or after _trackPageView. This was, after all, my main motivation in starting this library.

[mcclaskc]

Hi guys, how soon do you think the :custom_vars PR will be added? This is currently the exact problem that is keeping me from using this gem. I'm happy to do it if @yonda or @paracycle don't.

[yonda]

@paracycle @bgarret Thank you for your advice !
I guess it would be best to just turn this PR into a change that adds a :custom_vars option addition too .
I updated this RP , please review this PR .

[mcclaskc]

@yonda 👍

[paracycle]

@yonda This seems great, thanks.

The Travis build does not pass but that is related to a problem with the Rubinius build, so I am merging this.