Node Cookbook - Third Edition

Flow mode versus pull-based streaming

A Node stream can be in either non-flowing (pulling) or flowing (pushing) mode. When we attach a data event to a stream, it enters flowing mode, which means as long as there is data, the data event will be called.

myStream.on('data', handlerFunction)  

In the prior example snippet, if myStream was just created (and therefore a non-flowing stream by default), it would have been put into flowing mode via the act of attaching the data event.

If we want to stop data flowing through the stream, we can call the readable stream's pause method, and, when we want to start again, we can call the resume method.

myStream.pause() setTimeout(() => myStream.resume(), 1000) 

In the previous example, if myStream was already ...