0.23.7: When executed in a NW.js event handler setTimeout does not invoke its callback function

[semmel]

Must be a regression, since it has worked fine until after NW.js 0.22.3 The behaviour occurs for NW.js 0.23.7 in event handlers like nw.Window.on('close', handler).

I am running NW.js in Separate Context Mode without --mixed-context option.

An event handler like nw.Window.on('close', handler) has the Browser Context version of setTimeout in the global JS context. The observed behaviour is that it's worker function is never executed.

As a workaround one can employ setTimeout from the Node.js Context: global.setTimeout.

Here is the demo (Simply run in the Developer Console of the SDK build of NW.js 0.23.7)

nw.Window.open("https://www.example.com", { id: "Homepage", position:"center", width: 400, height: 600, resizable: true}, function(nwWindow){ 
 nwWindow.on('close', function(){
   // works on 0.23.7
    global.setTimeout(console.log.bind(console, "You can read this."), 500); 
    // works just on 0.22.3
    setTimeout(console.log.bind(console, "This is never executed"), 500);
  });

  nwWindow.close();
});

My workaround is to replace the Browser Context version of setTimeout entirely with the Node.js Context version:

setTimeout = global.setTimeout.bind(global);
clearTimeout = global.clearTimeout.bind(global);

To my surprise this seems to work.

Maybe setInterval is also affected?

[Christywl]

I can reproduce this issue on Linux/Windows on nwjs-sdk-v0.24.0.

[rogerwang]

After digging into it I found it should be expected: the 'setTimeout' function is bound to the global window object of the first window (which is under the security origin of chrome-extension://xyz), while the callback is executed in the context of the second window (security origin: www.example.com), which doesn't have the access to the first window and its function.

[rogerwang]

btw, using 'nwWindow.window.setTimeout' works as expected.

[semmel]

I think the callback should also have the context of the first window (chrome-extension://xyz).

• It is not code from the remote source (example.com), but from the NW.js app.
• Otherwise you cannot use third party libs in the handler, which relies on setTimeout, Promise.then etc.
• A workaround as you suggested is possible, but that would just add boilerplate code which in my opinion belongs into the NW.ja api.