Learning JavaScript Design Patterns A book by Addy Osmani [Pdf] Design patterns are reusable solutions to commonly occurring problems in software design. They are both exciting and a fascinating topic to explore in any programming language. One reason for this is that they help us build upon the combined experience of many developers that came before us and ensure we structure our code in an optimized way, meeting the needs of problems we're attempting to solve. Design patterns also provide us a common vocabulary to describe solutions. This can be significantly simpler than describing syntax and semantics when we're attempting to convey a way of structuring a solution in code form to others.
In this book we will explore applying both classical and modern design patterns to the JavaScript programming language. Target Audience This book is targeted at professional developers wishing to improve their knowledge of design patterns and how they can be applied to the JavaScript programming language. Acknowledgments Credits Reading We already use patterns everyday. Creating objects. Netscape 4, IE 4 on Windows and Mac, and IE 5 on Mac do not support the operator.
Any function in JavaScript can be used to create custom object classes, simply by calling it using the keyword new . When called in this way, the special variable inside the function references the new object that is being constructed (it normally refers to the 'current' object, which is usually , except inside methods). The function should not return a value. The following function can be used as demonstrated to create an object of class : function myobject() { this.containedValue = 0; this.othercontainedValue = 0; this.anothercontainedValue = 0; } var mything = new myobject(); And there you go, is now an instance of class . You could also now write this: myobject.prototype.newContainedValue = someValue; This will cause all instances of class will have the property with value . Use the instanceof operator to find out if your object is an instance of a given object class: Creating an object with methods. KAI.JAEGER.BLOG : The singleton design pattern in JavaScript.
Writing functions. General syntax Pre-alpha versions of Tkhtml Hv3 do not correctly interpret the Function class constructor. Functions group together script code; control structures, operations, method calls, etc. in the same way as a normal script. These functions can then be called when needed, and the code contained within them will be run. This makes it very easy to reuse code without having to repeat it within your script. Functions are defined using one of these constructs: Normal function construct function nameOfFunction(listOfVariableNames) { function code should be written here } Anonymous function, assigned to a variable Using this syntax for object methods in early Netscape 4 versions will cause problems with the 'this' keyword due to bugs. nameOfFunction = function (listOfVariableNames) { function code should be written here }; Normal function construct, assigned to a variable nameOfFunction = function anotherNameForTheFunction(listOfVariableNames) { function code should be written here }; Fade!
Essential JavaScript And jQuery Design Patterns. Jquery - Examples of practical javascript object oriented design patterns. JavaScript currying. Pro JavaScript Design Patterns: The Essentials of Object-Oriented JavaScript Programming [PDF] One-Line JavaScript Memoization. A JavaScript Module Pattern. Eric Miraglia (@miraglia) is an engineering manager for the YUI project at Yahoo. Eric has been at Yahoo since 2003, working on projects ranging from Yahoo Sports to YUI. For the past several years, Eric and his colleagues on the YUI team have worked to establish YUI as the foundation for Yahoo’s frontend engineering work while open-sourcing the project and sharing it with the world under a liberal BSD license.
Eric is an editor and frequent contributor to YUIBlog; his personal blog is at ericmiraglia.com. Prior to working at Yahoo, Eric taught writing at Stanford and elsewhere and led frontend engineering teams at several startups. Global variables are evil. Douglas Crockford has been teaching a useful singleton pattern for achieving this discipline, and I thought his pattern might be of interest to those of you building on top of YUI. 1. YAHOO.namespace("myProject"); This assigns an empty object myProject as a member of YAHOO (but doesn’t overwrite myProject if it already exists). 2.