Load existing media element

[therewasaguy]

Adds the ability to load an existing HTML5 or

Usage:

init wavesurfer with backend: 'MediaElement'.

 wavesurfer.util.ajax({
    responseType: 'json',
    url: waveformPath // path to .json file with precomputed waveform data
  }).
  on('success', function (data) {
      wavesurfer.loadExistingMediaElement( htmlElement, data);
  });

What is the best way to document this? Should I add a line to docs/methods.html in the gh-pages branch and an example?

If anyone has suggestions let me know and I'll happily update the PR.

( re #698 )

[coveralls]

Coverage decreased (-0.2%) to 4.587% when pulling 2805b72 on therewasaguy:load-existing-media-elt into 26657a8 on katspaugh:master.

[katspaugh]

Maybe we shouldn't change the way an existing element looks? It can be done in the app's CSS.

[katspaugh]

What is the best way to document this? Should I add a line to docs/methods.html in the gh-pages branch and an example?

Yeah, sure. An example with an existing video element would be nice, since it's asked about a lot.

Thank you very much!

[therewasaguy]

Thanks for your quick feedback, @katspaugh! All good points, and I'm sorry I should have updated some of these before sending the PR.

I will update this all soon, and I'll add a demo with video.

[coveralls]

Coverage decreased (-0.08%) to 4.667% when pulling 48ffdde on therewasaguy:load-existing-media-elt into 622322d on katspaugh:master.

[therewasaguy]

Updated and added an example using a <video>.

While consolidating the code, I was thinking... why not could just use load for existing media elements, rather than create a separate method? load does type checking and if the first argument is not a string (path to media file) but is instead an existing media element, load knows what to do. Does that sound like a good approach?

[katspaugh]

Thanks!

Does that sound like a good approach?

Yep, sounds like a good idea!

[katspaugh]

Why did you change this? If start is 0 we want to go to the beginning, not to the current position.

[therewasaguy]

Good call, I will revert this. While I was testing, setting media element .currentTime was always going back to zero, and I made this while troubleshooting before I realized it was due to the server (python simple server) and had nothing to do with the library. I should have reverted this and remembered that from your stack overflow post. Works fine on other servers.

[coveralls]

Coverage decreased (-0.08%) to 4.667% when pulling b3e8112 on therewasaguy:load-existing-media-elt into 622322d on katspaugh:master.

[coveralls]

Coverage decreased (-0.08%) to 4.667% when pulling b202eb1 on therewasaguy:load-existing-media-elt into 622322d on katspaugh:master.

[katspaugh]

Thanks a lot, @therewasaguy!