CODEWITHSUNDEEP
javascriptgoogle-chrome-extensiongoogle-chrome-devtoolschrome-native-messaging
Asesh
Asesh

Reputation: 3361

How do I find out if connectNative failed or succeeded

I have managed to connect my extension to our native host:

var pulse_tracker_port = chrome.runtime.connectNative('com.cloudfactory.pulsetracker');

but how do I find out if the connection succeeded or not? The value of 'pulse_tracker_report.name' will always be an empty string no matter if the connection succeeded or not.

I also tried to add listeners to find out if the connection succeeded or not but none of these callbacks are being invoked:

chrome.runtime.onConnect.addListener(function(port)
{
  console.log('Connected to "Pulse Tracker" @port: ' + port.name);
});

chrome.runtime.onConnectExternal.addListener(function(port)
{
  console.log('Connected to "Pulse Tracker" @port: ' + port.name);
});

BTW this won't be invoked either:

pulse_tracker_port.onConnect.addListener(function(port)
{
   console.log('Connected to "Pulse Tracker" @port: ' + port.name);
});

This is what I get when I try to do so: 

main.js:26 Uncaught TypeError: Cannot read property 'addListener' of undefined

onConnectExternal works for cross-extension messaging between extensions but looks like it doesn't work for native message hosting. Any help would be appreciated. Thanks

Upvotes: 1

Views: 1139

Answers (1)

Xan
Xan

Reputation: 77541

chrome.runtime.onConnect and chrome.runtime.onConnectExternal are not relevant here, since they notify you about incoming connections, not about state of outgoing connections.

pulse_tracker_port is a Port object which does not have onConnect property.

What you need to do is to immediately assign a listener to onDisconnect event of the port object. If there was a problem with the connection, the listener will be called and chrome.runtime.lastError will be set:

var pulse_tracker_port = chrome.runtime.connectNative('com.cloudfactory.pulsetracker');
pulse_tracker_port.onDisconnect.addListener(function() { 
  if (chrome.runtime.lastError) {
    console.error(chrome.runtime.lastError);
  }
});

Otherwise, just try to use it, with .postMessage() and .onMessage event. For postMessage, it will throw an error if the port is disconnected.

Upvotes: 4

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