Fix YouTube onReady bugs

[cookpete]

Attempts to fix #20

@Fauntleroy I'm hoping this does the job? Could you confirm?

[Fauntleroy]

Doesn't look like this fixes it... but I've got plenty of free time and a reproducible test case. I can go ahead and take care of this myself in a separate pull req if it's all the same to you

[Fauntleroy]

I spent quite a while working on reproducing this bug, making a test for it, and resolving it—but I could only get one of those complete. Here are the steps I used to replicate my issue:

• The player must be initialized with playing set to true and url set to null
• The YouTube player must be set to preload in the youtubeConfig
• Immediately after the player initializes, the url must be set to another YouTube URL (I did this within the test app's componentDidMount call)

This will cause the player to attempt to prime the YouTube player with the empty video, thus calling load, which ultimately calls new YT.player. Immediately after that the url is updated, which causes load to be called again, calling new YT.player and overwriting its original value. Eventually the first player's onReady fires, but by that time the second player (which is still initializing) is the value of this.player. Thus we try to call this.player.playVideo() (and other methods) when one of these players has initialized, but the other hasn't.

My idea for fixing this would be to add a flag for keeping track of whether or not we've started initializing a YouTube player yet. Using this flag, you could check to see if a player is pending during a load call, then act accordingly. If no player is initializing, create a new YouTube player. If a player is initializing, add the video ID to a queue and fire loadVideo or playVideo when onReady fires.

[cookpete]

Eventually the first player's onReady fires

This PR should prevent that first onReady from firing.

[cookpete]

Updated with a new approach. @Fauntleroy any better?

[cookpete]

Argh, still not good enough. Pausing/playing is now screwed up.

[cookpete]

Ah, never mind, I missed a ! here which caused problems. Oops.. I've fixed up master and rebased this branch.

[Fauntleroy]

This seems to be functioning as expected in both the react-player example and my application. I'm going to look over your code and see if there are any hidden gotchas before I sign off on this completely, though...

[Fauntleroy]

Having trouble with this in production. Let me double check my work first

[Fauntleroy]

Looks like the issue was probably caused by caching on my production server. Everything looks good to me here, though we should really start investing in tests as we move forward.

[cookpete]

we should really start investing in tests as we move forward.

Absolutely. Shallow rendering unit tests only get us so far. I'll open an issue.

I'll merge this and publish a patch release.