CODEWITHSUNDEEP
javascriptnode.jssocket.io
Srle
Srle

Reputation: 10496

socket.io, server emit event before client set up listener for that event

In the following code snippet(using node.js and socket.io library), sometimes (and sometimes not) server emit event something before client side set up socket listener for something event which will cause that associated anonymous function will not execute.

Client-side: index.html

<script src="socket.io/socket.io.js"></script>
<script>
   ...
   var socket = io.connect('http://localhost:8080/abc');
   ...
</script>
<script src="/somewhere/test.js"></script>

Content of test.js

...
console.log(new Date().getTime(), 'debugging');

socket.on('something', function(data) {
// will not execute
console.log(data);
});
...

Server-side:

io.of('/abc').on('connection', function(socket) { 
   console.log(new Date().getTime(), 'EMIT SOMETHING');
   io.of('/abc').emit('something', 'b');
});

Result of console.log on the client side: 1439057954676 debugging
Result of console.log on the server side: 1439057954114 EMIT SOMETHING

Why server emit event before client set up listeners in the above example?

Upvotes: 1

Views: 1946

Answers (1)

Shahar Nacht
Shahar Nacht

Reputation: 122

Try putting both var socket = io.connect('http://localhost:8080/abc'); and socket.on('something', function(data) in the same script tag.
(Essentially try making your whole script in one HTML element, instead of separating them.)

Upvotes: 0

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