socket.io中可以发出什么对象

Question

Using the socket.io library, what objects can I transmit to the client using the socket.emit method on the server side? For example, the socket.io site provides an example like the following

socket.emit('news', { hello: 'world' });

However, I couldn't find any documentation on the following questions when using the emit method:

• Could I used emit to transmit "any" JavaScript object, say one with methods, complex properties, etc?
• Should I instead convert my data/object to JSON and then transmit the JSON string. This would of course put some limitations on what objects could be transferred to the client.
• Does socket.io use JSON conversion when it actually does the transfer to the clients.

Answer 1

From their documentation :

All datastructures are supported, including Buffer. JavaScript functions can't be serialized/deserialized.

This means that you can emit a lot including JavaScript object literals. The only things you can't emit are functions because they are not serializable, so you will not be able to emit objects containing methods and have those methods be usable by the recipient. Nested properties would be allowed, though.

You don't have to convert the data ahead of time with emit , but you would with send . It stands to reason that socket.io does some conversion when it transfers the data to the client.