Lets go over what a browser does when it receives an html file. The window document is opened for writing.
The Module pattern is based in part on object literals and so it makes sense to refresh our knowledge of them first. Names inside the object may be either strings or identifiers that are followed by a colon.
Outside of an object, new members may be added to it using assignment as follows myModule. Where in the world is Paul Irish today? That said, if we're opting for this technique, we may be equally as interested in the Module pattern. It still uses object literals but only as the return value from a scoping function.
The Module Pattern The Module pattern was originally defined as a way to provide both private and public encapsulation for classes in conventional software engineering.
What this results in is a reduction in the likelihood of our function names conflicting with other functions defined in additional scripts on the page. Privacy The Module pattern encapsulates "privacy", state and organization using closures.
It provides a way of wrapping a mix of public and private methods and variables, protecting pieces from leaking into the global scope and accidentally colliding with another developer's interface. With this pattern, only a public API is returned, keeping everything else within the closure private.
This gives us a clean solution for shielding logic doing the heavy lifting whilst only exposing an interface we wish other parts of our application to use.
Variables can't technically be declared as being public nor private and so we use function scope to simulate this concept. Within the Module pattern, variables or methods declared are only available inside the module itself thanks to closure. Variables or methods defined within the returning object however are available to everyone.
History From a historical perspective, the Module pattern was originally developed by a number of people including Richard Cornford in It was later popularized by Douglas Crockford in his lectures. Another piece of trivia is that if you've ever played with Yahoo's YUI library, some of its features may appear quite familiar and the reason for this is that the Module pattern was a strong influence for YUI when creating their components.
Examples Let's begin looking at an implementation of the Module pattern by creating a module which is self-contained. The counter variable is actually fully shielded from our global scope so it acts just like a private variable would - its existence is limited to within the module's closure so that the only code able to access its scope are our two functions.
Our methods are effectively namespaced so in the test section of our code, we need to prefix any calls with the name of the module e. When working with the Module pattern, we may find it useful to define a simple template that we use for getting started with it.
Here's one that covers namespacing, public and private variables: The module itself is completely self-contained in a global variable called basketModule. The basket array in the module is kept private and so other parts of our application are unable to directly read it.
It only exists with the module's closure and so the only methods able to access it are those with access to its scope i. This gets automatically assigned to basketModule so that we can interact with it as follows: Notice how the scoping function in the above basket module is wrapped around all of our functions, which we then call and immediately store the return value of.
This has a number of advantages including: The freedom to have private functions and private members which can only be consumed by our module. As they aren't exposed to the rest of the page only our exported API isthey're considered truly private.
Given that functions are declared normally and are named, it can be easier to show call stacks in a debugger when we're attempting to discover what function s threw an exception.
J Crowder has pointed out in the past, it also enables us to return different functions depending on the environment.
In the past, I've seen developers use this to perform UA testing in order to provide a code-path in their module specific to IE, but we can easily opt for feature detection these days to achieve a similar goal.
Module Pattern Variations Import mixins This variation of the pattern demonstrates how globals e. This effectively allows us to import them and locally alias them as we wish.
This takes as its first argument a dot-separated string such as myObj. Using setObject allows us to set the value of children, creating any of the intermediate objects in the rest of the path passed if they don't already exist. For example, if we wanted to declare basket.
Here we’ll see how to create new elements “on the fly” and modify the existing page content. jQuery Coding Standards and Best Practices guide for helping programmers write better jQuery code. @Šime - I think there's only two ways to utilize the browser's HTML parser, innerHTML and urbanagricultureinitiative.com And if you think innerHTML is a hack – Alohci Sep 6 '11 at I have a problem in webtrends reporting where the URL of the page isn’t showing up.
The URL below is a pop-up box containing a form, but the current tracking is only capturing up to the ‘?’ and so in the reporting the page name is being displayed as ‘/’ – which of course, is not correct.
My style sheet is "test_css" and the style is "loading".Reviews: 4. I have taken time to review many of the discussions on this topic but have not found an answer to my question. In my site I am trying to optimize my page load speed and one of the ways I would like to do that is to move the my ad scripts to the bottom of the page to allow my content to load first.