DEV REQUEST: Overloading the pub.write() method. about rabbit.js HOT 4 CLOSED

Yeah, I was thinking of that, though I would probably put the optional argument (the topic) second.

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In the amqplib-based implementation, there's no 'topic' option at all yet. There is an undocumented feature whereby you can pass an object to #connect, specifying the exchange name, type and routing key -- but this doesn't really help much if you want to change the topic for each write.

Of course, #write already has a second argument, that is the encoding. So I think this would have to be another method, just for PUB sockets, perhaps #publish(topic, message, [encoding]).

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OK I have implemented #publish as above. There are implications.

One is that it doesn't make much sense unless a SUB socket can subscribe, in some way, to different topics. Here I've followed ZeroMQ, in that subscribing is distinct from connecting:

sub.connect('events');
sub.subscribe('critical.*');

But it's a breaking change, and the semantics are not obvious (do all subscriptions apply to all connections?), and it's all a bit confusing. So I may return to the structured-connection-address mentioned above -- that is, sub.connect({address: 'events', topic: 'critical.*'}) or even sub.connect('events', 'critical.*', callback).

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But it's a breaking change, and the semantics are not obvious (do all subscriptions apply to all
connections?), and it's all a bit confusing. So I may return to the structured-connection-address

Actually, I have added an optional argument to #connect, just for SUB sockets, for the topic. The kind of exchange is determined by the routing option given when creating the socket.

So, in its entirely, it looks like this:

var sub = ctx.socket('SUBSCRIBE', {routing: 'topic'});
var pub = ctx.socket('PUBLISH', {routing: 'topic'}); // must agree on routing if they are to talk
sub.connect('events', 'critical.*'); // the third argument would be a completion callback
pub.connect('events'); // ditto second argument
pub.publish('critical.alarm', "Emergency!", 'utf8');

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