RequireJS. Backbone.js. Zombies! RUN! (Managing Page Transitions In Backbone Apps) One of the common issues or questions I see for Backbone.js goes something like this: “Whenever I hit the same route more than once, I end up getting seeing this call being made multiple times. It seems to accumulate another call every time I hit the route.
What’s going on?” Or “I’ve noticed that my views are still handling events after I remove them from the screen. “How do I make sure I clean things up when moving to a new page in my app?” At the heart of all of these questions is a problem that most backbone developers will run into at some point: zombies. The Plague: Event Binding The majority of the problems that people are referring to in these questions and issues are caused by the events that we bind to in our apps. We bind events to our DOM elements using the declarative `events` configuration in our views: We bind events from our models and collections so that our views can respond to changes and re-render themselves: Events are everywhere, and with good reason.
Rule #2: Double Tap. Backbone patterns. Building apps with Backbone.js Here, I try to document the good practices that our team has learned along the way building Backbone applications. This document assumes that you already have some knowledge of Backbone.js, jQuery, and of course, JavaScript itself. Table of contents Thanks. JsPerf: JavaScript performance playground. JavaScript Garden. Although JavaScript deals fine with the syntax of two matching curly braces for blocks, it does not support block scope; hence, all that is left in the language is function scope. function test() { // a scope for(var i = 0; i < 10; i++) { // not a scope // count } console.log(i); // 10} There are also no distinct namespaces in JavaScript, which means that everything gets defined in one globally shared namespace.
Each time a variable is referenced, JavaScript will traverse upwards through all the scopes until it finds it. In the case that it reaches the global scope and still has not found the requested name, it will raise a ReferenceError. The Bane of Global Variables // script Afoo = '42'; // script Bvar foo = '42' The above two scripts do not have the same effect. Again, that is not at all the same effect: not using var can have major implications. // global scopevar foo = 42;function test() { // local scope foo = 21;}test();foo; // 21 Local Variables var foo = 3; bar = 4;}test(10); Hoisting.