When we created the External Media addition to ARI we created an ExternalMedia object to be returned from the channels/externalMedia REST
endpoint. This object contained the channel object that was created plus local_address and local_port attributes (which are also in the Channel variables). At the time, we thought that creating an ExternalMedia object would give us more flexibility in the future but as we created the sample speech to text application, we discovered that it doesn’t work so well with ARI client libraries that a) don’t have the ExternalMedia object defined and/or b) can’t promote the embedded channel structure to a first-class Channel object.

Example:

A common pattern using the node-ari-client is to create a new Channel object, attach an event handler to it, then call originate on it like so…

chan = ari.channels.Channel();
chan.on(‘StasisStart’, );
chan.originate(…);

With the current ExternalMedia API:

chan = ari.channels.Channel();
chan.on(‘StasisStart’, );
chan.externalMedia(…);

This doesn’t work however because the return from channels/externalMedia isn’t a Channel. It’s an ExternalMedia object with an chlld object that looks like a Channel but has no Channel behavior attached to it. The event handler added to chan will never get called and you can’t attach handlers or perform any operations on ExternalMedia.channel because it’s just a plain object, not an instance of Channel.

Realistically, it doesn’t make sense to force client library implementations to create special logic to promote the ExternalMedia.channel object into an instance of Channel and since External Media is a new capability anyway, it seems that the least painful solution is to remove the ExternalMedia object and have channels/externalMedia return a Channel object directly, just like channels/create and channels/originate. As I described above, the only other attributes of ExternalMedia were the local address and port and they’re already available in the Channel variables anyway.

I would think that this change would make things easier for ARI developers but I wanted to make sure that you knew about it in advance and had a chance to comment. There will be a Gerrit review up for this change later this morning.

Also… I mentioned the “sample speech to text application” above. It’s working and will be published next week.

Comments? Questions?