javascript design patterns pdf

access a public variable, the name of the main object must be repeated. He doesn't like it either. When using module mode, you must switch to object literal notation to make a method public.He creates a new pattern that simply defines all of the functions and variables within the private scope and returns an anonymous object that has a pointer to a private function that he wants to show as public.Example:var revealingmodule= (function () { var privatevar= "Private", publcvar= "Hello

function MyArray () { var values=new Array (); Values.push.apply (values,arguments); // method of its own definition values.topipedstring =function () { return this . Join (' | ') ); }; return var colors= instanceof Array); Seven, the safe structure function patternThe secure constructor follows the pattern of the parasitic constructor type, but has a difference of two points: one is not to usethis, and the other is not to call the constructor with newfunctionPerson (n

Introduction to the prototype of JavaScript design patterns (Object. create and prototype), object. prototype Prototype description Note: You can use a prototype instance to copy and create new custom objects. You do not need to know the specific process of creating the original object; Process: Prototype => new ProtoExam => clone to new Object; Use the relevant

Introduced The skin pattern (façade) provides a consistent interface for a set of interfaces in a subsystem, which defines a high-level interface that is worth the most use of the subsystem. Body The appearance pattern not only simplifies the interfaces in the class, but also makes the interface and the caller aware of the decoupling. The appearance pattern is often considered a prerequisite for developers, it can encapsulate some complex operations and create a simple interface for invocatio

; One } A - varcalculate =function(Func, salary) {//Higher order functions - returnfunc (salary); the }; - -Calculate (S, 20000);//Output: 80000 -Calculate (A, 10000);//Output: 30000Or use objects so that policies can relate to each other:1 varLv = {2"S":function(Salary) {3 returnSalary * 4;4 },5"A":function(Salary) {6 returnSalary * 3;7 },8"B":function(Salary) {9 returnSalary * 2;Ten } One }; A -

the complexity of some calls, but they also enhance the flexibility of iterators, and we can manually control the process or order of iterations.4. The iterator pattern can not only iterate over algebraic groups, but also iterate over the objects of some class arrays.In JavaScript, the for-in statement can be used to iterate over the properties of an ordinary literal object.5. Reverse Iterator6. Abort iterator7. Application examples8. SummaryThe iter

[namespace] = ret): ret; };Return {create: _create, one:function(Key,fn,last) {var event =This.create (); Event.one (Key,fn,last); }, remove:function(KEY,FN) {var event =This.create (); Event.remove (KEY,FN); }, listen:function(Key,fn,last) {var event =This.create (); Event.listen (Key,fn,last); }, Trigger:function(){var event =This.create (); Event.trigger.apply (Thisarguments); } }; }();return Event;}) ();/********* first post-subscription *********/event.trigger (' Click ',1); Event.listen ('

executed, which can also be done with a history list stack. Logging command logs and then repeating them is a good way to reverse an irreversible command.Command queueMacro command:A macro command is a collection of commands that can execute a batch of commands at a time by executing a macro command. varClosedoorcommand ={execute:function() {Console.log (Closed); } }; varOpenpccommand ={execute:function() {Console.log (' Turn on the computer '); } }; varOpenqqcommand ={execute:fu

This pattern involves a single class which provides simplified methods required by client and delegates calls to methods O F Existing system classes./** * Design patterns-facade Pattern * https://www.tutorialspoint.com/design_pattern/facade_pattern.htm */// Interfacefunction shape () {}shape.prototype.draw = function () {throw "Shape::d Raw () must be overridden";};/ /Implements Shapefunction Rectangle () {

Reference resources: In-depth understanding of JavaScript series by Uncle TomA single example is to ensure that a class has only one instance, the method of implementation is generally first to determine whether the instance exists or not, if there is a direct return, if it does not exist to create a return, this ensures that a class has only one instance object.The object literal is the simplest single-case pattern:var mysingleton = { "a property"

(navigator.cookieenabled + "“) document.write (" User Agent header for browser: ")document.write (Navigator.useragent + "“) //=========var x = navigator;document.write ("codename=" + x.appcodename);document.write ("“);document.write ("minorversion=" + x.appminorversion);document.write ("“);document.write ("name=" + x.appname);document.write ("“);document.write ("version=" + x.appversion);document.write ("“);document.write ("cookieenabled=" + x.cookieenabled);document.write ("“);document.write (

); Where.appendchild (TXT); };};//Child function 2: Working with linksPage.dom.Link =function() { This. Insert =function(where) {varlink = document.createelement (' a '); Link.href = This. URL; Link.appendchild (document.createTextNode ( This. url)); Where.appendchild (link); };};//Child function 3: working with picturesPage.dom.Image =function() { This. Insert =function(where) {varim = document.createelement (' img '); IM.SRC = This. URL; Where.appendchild (IM); };};So how do we define

1. Publish-Subscribe mode is also called the Observer pattern, which defines a one-to-many dependency between objects.2. How to implement the Publish-subscribe mode2-1. First specify a good publisher2-2, add a buffer list to the publisher, the user holds the callback function to inform the Subscriber2-3. When the last message is published, the Publisher will traverse the cache list and trigger the subscriber callback functionExample:var salesOffice = {};Salesoffice.clientlist = [];Salesoffice.li

1, the core of the singleton mode is to ensure that there is only one instance and provide global access.2. An inert singleton refers to creating an object instance when needed.such as creating a unique div in the page general practicevar Creatediv = (function () {var Div;return function () {if (!div) {div = document.createelement ("div");Div.style.width= "100px";div.innerhtml = "FDSAFDSAFDSAFDSA";Div.style.display = ' None ';Document.body.appendChild (DIV);return div;}return div;}})();document.

=Function (){Console. Log ('Dialog before ...') // Here we will perform specific operations. Handler. Prototype. Handle. Call ( This ); // Continue to go up Console. Log ('Dialog after ...')}; VaR Button = New Handler (dialog, 2 );Button. Handle =Function (){Console. Log ('button before ...') // Here we will perform specific operations. Handler. Prototype. Handle. Call ( This );Console. Log ('button after ...')};Button. Handle (); We can see from the running results of the Code tha

JavaScript Learning notes-creating object Design Patterns

and polymorphism.The policy model provides perfect support for the open-closed principle, encapsulating the algorithms in separate startegy, making them easy to switch, easy to understand, and easy to extend.Algorithms in the policy model can also be reused elsewhere in the system, avoiding many repetitive copy-pasting efforts.Using composition and delegation in the policy model allows the context to have the ability to execute algorithms, which is a more portable alternative to inheritance.In

iterator: Sets the callback function to the callback to return false when it jumps out of the loopExamples of applications for iterators: When file uploads are available in many ways, avoid using conditional selection statements to choose how to uploadThe solution might be: Each upload method is written as a function, the function returns the Upload object, and returns False if it is an incompatible upload method. Iterate through all the functions of the upload method as an array,

Web-side when a large number of DOM data insertion, if a one-time insertion of thousands of data, the browser will be unable to appear in the case of the death of Kaka, the code is as follows:vararr = []; for(vari = 0; i ) {Arr.push (i);}varLoadData =function(data) { for(vari = 0, L = data.length; I ){ varElem = document.createelement (' div '); Div.innerhtml=i; Document.body.appendChild (DIV); }};loaddata (arr);//Create a Timechunk () function to insert the DOM in batchesvarTimechunk

is returned. use hasOwnProperty () method can detect whether a property exists in an instance or exists in a prototype. This method (do not forget that it is inherited from object) returns true only if the given property exists in the object instance . Take a look at the following example.function person () {}person.prototype.name= "Nicholas"; Person.prototype.age= 29; person.prototype.job= "Software Engineer"; Person.prototype.sayname= function () { alert (this.name);}; va