node.js - How to get channelid in pubnub subscribe/or publish function? -

this subscribe code want channelid used this.channel in code got undefined. there way can channelid

pubnub.subscribe({     channel: changing dynamically,     presence: function (m) {         console.log(m)     },     message: function (m) {         console.log(m);         console.log("channel ==" + this.channel)     },     error: function (error) {         // handle error here         console.log(json.stringify(error));     } }) 

result: channel==undefined

looking @ the fine manual, should work:

pubnub.subscribe({     channel: changing dynamically,     presence: function (m) {         console.log(m)     },     message: function (m, env, channel) {         console.log(m);         console.log("channel ==" + channel)     },     error: function (error) {         // handle error here         console.log(json.stringify(error));     } }) 

in other words, channel passed argument message callback.

the reason this.channel being undefined message callback isn't called in context of object passed pubnub.subscribe().