asynchronous request filters

[priyajeet]

I am currently using v1 which allows request intercepting via source.setNetworkCallback(foo) and I believe the v2 equivalent for this is player.getNetworkingEngine().registerRequestFilter(foo)

In both cases I want to make a network request (or some async operation) inside foo, the result of which will be used in the actual filtering.

An example would be that I need to intercept all dash requests and decorate the headers with an authentication token. However this token may have expired half way during playback of the video. So I need to fetch a new token before allowing the next dash network request to happen. Essentially pausing it.

My current workaround is to increase the number of network retries for the dash player, and manage the token refresh outside the scope of the player network interceptor. This isolated token refresh request then alters some scope variable that function foo can eventually read. This works but is hacky and results in bunch of errors, say 401, but having a high retry count (and coupled with the new v2 backoffFactor) gets this going.

Another example would be that the dash player requests for a segment, however that response returns, say a 202, suggesting that the segment is still transcoding on the backend and not ready. One would like to prevent further requests till some async job suggests that the segment is ready and is OK to continue.

Can player.getNetworkingEngine().registerRequestFilter(foo) have foo that returns a promise which resolves to a modified shakaExtern.Requestupon which it should make the actual dash request.

[joeyparrish]

Asynchronous networking filters seems like a pretty reasonable feature request. We'll look into it for v2.1. We will try to keep it backward-compatible with the synchronous filters we have today.

[joeyparrish]

Looks like we still need to update the externs for request and response filters and add something to the docs.

[joeyparrish]

And we still need to make the response filters async as well.