Implement setOptOut cookie command

[jaswrks]

NOTE: Please consider merging #9156 instead of this.

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PR Objectives

• Implement the upcoming setOptOut command; i.e., whenever the new privacy option is changed, this PR will set or unset the opt-out cookie using window._tkq.push( [ 'setOptOut', true|false ] )

• Make Jetpack_Tracks_Client in PHP aware of this cookie too. If the opt-out cookie exists, do not record server-side events either.

How to test:

• Depends on Add new settings route and page for Privacy settings #8993 and Add/user tracking option api #9003 These are merged already.
• In a browser console, run: localStorage.setItem( 'debug', 'dops:analytics' );
• Open the new Privacy setting described and implemented by Add new settings route and page for Privacy settings #8993
• Toggle the privacy option on/off and observe browser console
• Expect to see Pushing setOptOut: true|false

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Blocker

This will not actually set the cookie, it merely logs what would occur if setOptOut existed. Therefore, this PR cannot be tested any further at this time. The work in gh-analytics-38 (setOptOut command) needs to exist in w.js as well, which I am investigating.

Unresolved Questions

• Will the final option key for opt-outs in Jetpack remain jetpack_event_tracking? This question has been raised in: p7kMJG-4rC-p2 and is pending further discussion. Yes
• Should setOptOut disable Google Analytics in addition to Tracks? No

[oskosk]

@jaswrks this PR is not passing some JS tests. Mostly due to an attempt to access window from the state-handling code (an action). So, when the tests run on the console, window is not defined there.

[zinigor]

Makes sense to me, looks good, except I have one question.

[zinigor]

Why is this getting set in the catch block instead of in the success block?

[jaswrks]

@zinigor Thank you for catching this!

Makes sense to me, looks good, except I have one question.

Fixed in da1219f

[oskosk]

@jaswrks moving the tracking behaviour to somewhere on the react side of things (instead of on the redux action creator) would be a preferred solution for the problem I mentioned earlier.

[jaswrks]

@oskosk writes...

@jaswrks this PR is not passing some JS tests. Mostly due to an attempt to access window from the state-handling code (an action). So, when the tests run on the console, window is not defined there.

Thank you. I see what you mean. I reviewed the Travis output and I see this is a result of me importing /_inc/client/lib/analytics, which depends on window.

Does anyone have a suggestion about how to best approach a fix for this and get tests to pass? Am I doing something really unexpected by importing the analytics code in this PR? Or is this missing window var a separate area of concern as it relates to the test environment?

[jaswrks]

@jaswrks moving the tracking behaviour to somewhere on the react side of things (instead of on the redux action creator) would be a preferred solution for the problem I mentioned earlier.

Copy that :-) Ty

[jaswrks]

@oskosk Thank you. I altered my approach in this PR in the last commit: bc3d5c4

[jaswrks]

A potentially better alternative now exists in #9156

[jaswrks]

Closing, superseded by #9156