FR: Prevent HTML Audio Tag Injection (lazyload option)

Hi,

This is a follow-up a the issue discussed on the Bug: Browsers don’t respect setting preload to “none” in wavesurfer.load() issue.

Context

This issue concerns using MediaElement backend and Cached Peaks.

Problem

Some browsers ignore the preload=none attribute of audio tags. This means that in some cases, audio files are loaded even if not needed.

Proposition

Only inject audio HTML tags when needed (aka, after a custom event). For this, we can imagine having a lazyload wavesurfer init option attribute, to init the object. Initializing the object also require knowing its length before hand. (attribute integration proposition by @mspae : https://github.com/katspaugh/wavesurfer.js/commit/1025d7263e32f087a3404012dbf0301e5f95b383 ) This will not be a problem with cached data (the length can be added in the cache file).

This will increase wavesurfer performance and some browser/OS (like Safari+MacOS) a lot ! 😃 Thanks for taking a look !

[mspae]

@X-Raym I’ve opened a PR on the duration parameter.

[X-Raym]

@thijstriemstra What I meant is that I don’t know how to implement this lazyload option, wavesurfer.js is a pretty complex script.