javascript design patterns pdf

, the Observer (or object) wishing to receive topic notifications must subscribe this int Erest to the object firing the event (the subject).The Publish/subscribe pattern however uses a topic/event channel which sits between the objects wishing to receive notific Ations (Subscribers) and the object firing the event (the publisher). This event system allows code to define application specific events which can pass custom arguments containing values need Ed by the Subscriber. The idea here's to av

: Resultsetinterface. var ResultSet =new Interface ("ResultSet", [' getDate ', ' getresults ']); This line of code above creates a new instance of the interface object. The first argument is the name of the interface, and the second argument is an array of strings, each of which is a required method name. With this interface, you can use an interface check to replace the instanceof check var resultformatter = function (resultsobject) { interface.ensureimplements (resultsobj

the Addevent function is entered:1 varAddevent =function(Elem, type, handler) {2 if(window.addeventlistener) {3Addevent =function(Elem, type, handler) {//the difference between this and the previous scenario is that it rewrites itself.4Elem.addeventlistener (type, Handler,false );5 }6}Else if(window.attachevent) {7Addevent =function(Elem, type, handler) {8Elem.attachevent (' on ' +type, handler);9 }Ten } OneAddevent (Elem, type, handler);//This will only be performed the

event bubbling mechanism in the DOM seems a bit like this, for example, after clicking a button, if it doesn't stop bubbling, its Click event will always bubble up to the parent element, and this mechanism can also handle many related problems, such as Example 1: Event centralized management in this series of design pattern sharing meta-mode Example code. Reference code: HTTPS://gist.github.com/1174982synchronization and recommendation this article h

("---------------------------------------------"Are you familiar with the development of ASP. The usage scenario for summarizing the combination pattern is very clear: you want to represent the part of the object-The overall hierarchy; If you want users to ignore the combination object and the individual object, the user will uniformly use all the objects in the composite structure (methods) In addition, the pattern is often used in conjunction with decorators, which usually have a common paren

() { var ret = _self.apply (this, arguments); Afterfn.apply (this, arguments); return ret; }; document.getElementById = Document.getElementById.before (function () { console.log (1); }); Third, avoid the pollution of the prototype var before = function (FN, beforefn) {return function () { beforefn.apply (this, arguments); Return fn.apply (this, arguments); }; var after = function (FN, AFTERFN) {return function () { var ret = fn.appl

Before you learn JavaScript design patterns, you need to understand some of the relevant knowledge, object-oriented basics, this and other important concepts, as well as mastering some functional programming skills.JS polymorphicPolymorphic thinking: Actually separating "what to do" from "who Does it".Cases:var makesound = function (animal) { if (animal.show i

Javascript Design PatternsThe first chapter of flexible JavaScript Using functions to incorporate objects var checkobject={Checkname:function () {},Checkemail:function () {},Checkpassword:function () {}} True and False objects Var checkobject=function () {return{Checkname:function () {},Checkemail:function () {},Checkpassword:function

Reading Notes-javascript design patterns-interfaces, encapsulation, and chain callsThere are three main reasons for using the design pattern in javascript: maintainability: The design pattern helps reduce the coupling between modu

function.The JavaScript scope is also lexical in nature, meaning that the function runs in her definition of her scope, not in the scope of the call it, two together, you can wrap the variable in the function, and protect it, to create (private variables of the class)var test;(function () { var foo = 10;var bar = 2;Test = function () { return foo*bar;} })(); 1.4, the variability of the object1. You can add properties to a functionfunction DisplayErro

"); } }; Function.prototype.after = function (fn) {var self = this; return function () {var ret = self.apply (this, arguments); if (ret = = "Nextsuccessor") {return fn.apply (this, arguments); return ret; }; var order = Order500.after (order200). After (Ordernormal); Order (1, true, 10); Advantage: Decoupling the complex relationship between the requesting sender and the n recipient.Disadvantage: There is no guarantee that a request will be handled by the nodes in the chain. I

the adorner mode is intended to add functionality to the Object. The decorator pattern often forms a long decorative chain, while the adapter pattern is usually packaged only once. The proxy mode is to control access to objects and is usually wrapped only once. The function of the appearance mode is similar to the adapter, Some people regard the appearance pattern as the adapter of a set of objects, but the most notable feature of the appearance mode is the definition of a new interface.

example as follows:functionCar (model, year, miles) { This. Model =model; This. Year =Year ; This. Miles =miles;} //Note Here, we are using Object.prototype.newMethod rather than//Object.prototype so as to avoid redefining the prototype ObjectCar.prototype.toString =function () { return This. Model + "have done" + This. Miles + "Miles";}; //Usage: varCIVIC =NewCar ("Honda Civic", 2009, 20000 );varMondeo =NewCar ("Ford Mondeo", 2010, 5000 ); Console.log (Civic.tostring ()); Console.log (mond

implementing the different, he can call all the methods in the same way, reducing the coupling between the various algorithm classes and using the algorithm class. On the other hand, it is easy to define the algorithm classes individually, as well as unit tests, because they can be individually tested by their own algorithms. In practice, not only can encapsulation algorithms, but also can be used to encapsulate almost any type of rules, in the analysis process need to apply different business

addevent wraps the correct logical function, the code is as followsBut there is still one drawback to this function, assuming that we have not used the Addevent function from beginning to end.The third option is to use the lazy loading scheme, the first time you enter the conditional branch, the function will be overridden inside the function, the rewritten function is what we expect the Addevent function, the next time we enter the Addevent function, Addevent does not exist those branch judgme

, simply declaring it, without implementingvar Composite = new Interface (' Composite ', [' Add ', ' Remove ', ' getchild ']);Declaring an interface, simply declaring it, without implementingvar FormItem = new Interface (' FormItem ', [' Save ']);Declaring the implemented classfunction MenuItem (ID, method, action) {...This.show = function (object) {Interface.ensureimplements (This, [Composite, MenuItem]);Ensure that the class object implements the Composite, MenuItem interface, in order to perf

is the key of the system, which is the intermediary role in software design. Let's start with pseudocode to understand: Copy Code code as follows: The following code is pseudo code, please do not care too much about the code The app namespace is the equivalent of acting as an intermediary. var app = App | | {}; Ajax requests via the app broker App.sendrequest = function (options) { Return $.ajax ($.extend ({}, Options);

This article mainly introduces a deep understanding of the JavaScript series (25): a detailed explanation of the Singleton mode of the design mode. This article provides implementation methods of multiple Singleton modes. For more information, see Introduction Starting from this chapter, we will gradually introduce the implementation of various design

of subclasses. The decorator pattern and the composition pattern have a lot in common, they all implement a uniform interface with the wrapped object and will pass any method bar to these objects. However, the combination mode is used to organize many sub-objects into a whole, while the decorator pattern is used to add methods to the existing objects without modifying them or deriving subclasses from them. As follows:1 var m = {}; 2 m.child = {}; 3 function () {}; 4 function () {};Vi. Observer

=function(){ This. Receiver.add ();};varDelsubmenucommand=function(receiver) { This. receiver=receiver;};D ElSubMenuCommand.prototype.execute=function{ This. Receiver.del ();}Finally, the command receiver is passed into the commands object, and the order object is bound to the buttonvar refreshmenubarcommand=New Refreshmenubarcommand (MenuBar); var addsubmenucommand=New Addsubmenucommand (submenu); var delsubmenucommand=New Delsubmenucommand (submenu); SetCommand (button1, Refreshmenu