node js event loop monitoring

This article mainly introduces Custom Event instances in node. js. A simple example. For more information, see the EventEmitter that inherits events, then you can register the event through the on; emit triggers the event and removeListener removes the

In JavaScript learning, we often encounter JavaScript event mechanisms, such as event binding, event monitoring, event delegation (event broker), and so on. What do these nouns mean, and what is the effect?

Write in front:A sentence as the core of this article: Object monitoring event, event trigger function;(i) Events1. Event classification(1) Mouse eventsClick () mouse clicksDblClick () mouse double-clickMouseOver () mouse move-in eventMouseout () mouse out eventMouseMove () mouse Move EventMouseDown () mouse down event

In node. js development, the Node Supervisor is used to modify the monitoring file and automatically restart the application. In the development or debugging of Node. when you modify a js application, you always need to press CTRL

In the front-end development process, we often encounter problems with adding events to page elements, add the event of the JS method is also a lot of directly added to the page structure, there is a use of some JS event monitoring method, due to the different browser

, RemoveListener , Removealllistener , emit and other basic methods of event monitoring mode implementation.It is not the same as the events on the front-end DOM tree, because it does not have event bubbling , layer-wise capture, and other events that belong to the DOM, nor Preventdefault (), Stoppropagation (), Stopimmediatepropagation () Methods for handling

In the front-end development process, we often encounter problems with adding events to page elements, add the event of the JS method is also a lot of directly added to the page structure, there is a use of some JS event monitoring method, due to the different browser

, Removealllistener , emit and other basic methods of event monitoring mode implementation.It is not the same as the events on the front-end DOM tree, because it does not have event bubbling , layer-wise capture, and other events that belong to the DOM, nor Preventdefault (), Stoppropagation (), Stopimmediatepropagation () Methods for handling

Monitoring.Event MonitoringAbout event monitoring, The 3 event stages are defined in the code, which is the capturing phase, the target stage and the bubbling Stage.At first Netscape developed a set of JavaScript Event-driven mechanisms (I.E. event captures). IE also launch

parses JavaScript scripts.(2) The parsed code calls the node API.(3) The LIBUV Library is responsible for the execution of the node API. It assigns different tasks to different threads, forming an event loop (the loop of events) that asynchronously returns the execution res

The biggest feature of zookeeper Node. js is the close integration of asynchronous I/O with events. This mode is very different from the traditional synchronous I/O linear programming approach, because the control flow depends largely on events and callback functions, A logic is split into several cells. Contents: blocking and thread 1. synchronous I/O or blocking I/O threads usually take a long time if the

Document directory Understanding callback Mode Understanding event transmitter Mode Understanding event types Use the event transmitter API Create an event Transmitter For the list of articles in this series and the translation progress, see Node.

that the next code can be executed while the file is being read, greatly improving the performance of the program. As a result, blocking is performed sequentially, not blocking is not required in order, so if you need to handle the parameters of the callback function, you need to write it inside the callback function. *///=========================node.js Events and Event loops/*node.

more difficult,But the good news is that there are many libraries, such as async, that specialize in solving asynchronous programming problems, see Section 6.2.2.Let's look at how to read a file asynchronously in node. js, here's an example:Readfile.jsvar fs = require (' FS ');Fs.readfile (' file.txt ', ' utf-8 ', function (err, data) {if (err) {Console.error (ERR);} else {Console.log (data);}});Console.lo

emitter.addListener("hello",function(){ console.log("Hello");});//使用emit函数发射事件emitter.emit("hello");Registering an event listener with parametersThe registered listener can take the parameters directly and add the corresponding parameters when the emit launch event. Example://事件发射器类声明var EventEmitter = require("events").EventEmitter;//创建事件发射器varnew EventEmitter();//使用on添加监听器emitter.on("hello",function(n

Appbox in Main.aspx.csif (menu. Istreeleaf){Node. Leaf = true;}Else{Node. Singleclickexpand = true;}---if node. Singleclickexpand = True when the current node node has a linked page, the linked page opens in a new window when clicked.?---I want to open the linked page as a t

return results is put into the execution callback function of the code, thus improving the efficiency of the function execution.When an I/O execution is complete, the thread that performs the I/O operation is notified as an event, and the thread executes the callback function for the event, in order to handle the asynchronous I/O, the thread must have an event