Closed. This question is opinion-based. It is not currently accepting answers.
Want to improve this question? Update the question so it can be answered with facts and citations by editing this post.
Closed 8 years ago.
Improve this question
As JavaScript frameworks like jQuery make client side web applications richer and more functional, I've started to notice one problem...
How in the world do you keep this organized?
Put all your handlers in one spot and write functions for all the events?
Create function/classes to wrap all your functionality?
Write like crazy and just hope it works out for the best?
Give up and get a new career?
I mention jQuery, but it's really any JavaScript code in general. I'm finding that as lines upon lines begin to pile up, it gets harder to manage the script files or find what you are looking for. Quite possibly the biggest propblems I've found is there are so many ways to do the same thing, it's hard to know which one is the current commonly accepted best practice.
Are there any general recommendations on the best way to keep your .js files as nice and neat as the rest of your application? Or is this just a matter of IDE? Is there a better option out there?
EDIT
This question was intended to be more about code organization and not file organization. There has been some really good examples of merging files or splitting content around.
My question is: what is the current commonly accepted best practice way to organize your actual code? What is your way, or even a recommended way to interact with page elements and create reuseable code that doesn't conflict with each other?
Some people have listed namespaces which is a good idea. What are some other ways, more specifically dealing with elements on the page and keeping the code organized and neat?
It would be a lot nicer if javascript had namespaces built in, but I find that organizing things like Dustin Diaz describes here helps me a lot.
var DED = (function() {
var private_var;
function private_method()
{
// do stuff here
}
return {
method_1 : function()
{
// do stuff here
},
method_2 : function()
{
// do stuff here
}
};
})();
I put different "namespaces" and sometimes individual classes in separate files. Usually I start with one file and as a class or namespace gets big enough to warrant it, I separate it out into its own file. Using a tool to combine all you files for production is an excellent idea as well.
I try to avoid including any javascript with the HTML. All the code is encapsulated into classes and each class is in its own file. For development, I have separate <script> tags to include each js file, but they get merged into a single larger package for production to reduce the overhead of the HTTP requests.
Typically, I'll have a single 'main' js file for each application. So, if I was writing a "survey" application, i would have a js file called "survey.js". This would contain the entry point into the jQuery code. I create jQuery references during instantiation and then pass them into my objects as parameters. This means that the javascript classes are 'pure' and don't contain any references to CSS ids or classnames.
// file: survey.js
$(document).ready(function() {
var jS = $('#surveycontainer');
var jB = $('#dimscreencontainer');
var d = new DimScreen({container: jB});
var s = new Survey({container: jS, DimScreen: d});
s.show();
});
I also find naming convention to be important for readability. For example: I prepend 'j' to all jQuery instances.
In the above example, there is a class called DimScreen. (Assume this dims the screen and pops up an alert box.) It needs a div element that it can enlarge to cover the screen, and then add an alert box, so I pass in a jQuery object. jQuery has a plug-in concept, but it seemed limiting (e.g. instances are not persistent and cannot be accessed) with no real upside. So the DimScreen class would be a standard javascript class that just happens to use jQuery.
// file: dimscreen.js
function DimScreen(opts) {
this.jB = opts.container;
// ...
}; // need the semi-colon for minimizing!
DimScreen.prototype.draw = function(msg) {
var me = this;
me.jB.addClass('fullscreen').append('<div>'+msg+'</div>');
//...
};
I've built some fairly complex appliations using this approach.
You can break up your scripts into separate files for development, then create a "release" version where you cram them all together and run YUI Compressor or something similar on it.
Inspired by earlier posts I made a copy of Rakefile and vendor directories distributed with WysiHat (a RTE mentioned by changelog) and made a few modifications to include code-checking with JSLint and minification with YUI Compressor.
The idea is to use Sprockets (from WysiHat) to merge multiple JavaScripts into one file, check syntax of the merged file with JSLint and minify it with YUI Compressor before distribution.
Prerequisites
Java Runtime
ruby and rake gem
You should know how to put a JAR into Classpath
Now do
Download Rhino and put the JAR ("js.jar") to your classpath
Download YUI Compressor and put the JAR (build/yuicompressor-xyz.jar) to your classpath
Download WysiHat and copy "vendor" directory to the root of your JavaScript project
Download JSLint for Rhino and put it inside the "vendor" directory
Now create a file named "Rakefile" in the root directory of the JavaScript project and add the following content to it:
require 'rake'
ROOT = File.expand_path(File.dirname(__FILE__))
OUTPUT_MERGED = "final.js"
OUTPUT_MINIFIED = "final.min.js"
task :default => :check
desc "Merges the JavaScript sources."
task :merge do
require File.join(ROOT, "vendor", "sprockets")
environment = Sprockets::Environment.new(".")
preprocessor = Sprockets::Preprocessor.new(environment)
%w(main.js).each do |filename|
pathname = environment.find(filename)
preprocessor.require(pathname.source_file)
end
output = preprocessor.output_file
File.open(File.join(ROOT, OUTPUT_MERGED), 'w') { |f| f.write(output) }
end
desc "Check the JavaScript source with JSLint."
task :check => [:merge] do
jslint_path = File.join(ROOT, "vendor", "jslint.js")
sh 'java', 'org.mozilla.javascript.tools.shell.Main',
jslint_path, OUTPUT_MERGED
end
desc "Minifies the JavaScript source."
task :minify => [:merge] do
sh 'java', 'com.yahoo.platform.yui.compressor.Bootstrap', '-v',
OUTPUT_MERGED, '-o', OUTPUT_MINIFIED
end
If you done everything correctly, you should be able to use the following commands in your console:
rake merge -- to merge different JavaScript files into one
rake check -- to check the syntax of your code (this is the default task, so you can simply type rake)
rake minify -- to prepare minified version of your JS code
On source merging
Using Sprockets, the JavaScript pre-processor you can include (or require) other JavaScript files. Use the following syntax to include other scripts from the initial file (named "main.js", but you can change that in the Rakefile):
(function() {
//= require "subdir/jsfile.js"
//= require "anotherfile.js"
// some code that depends on included files
// note that all included files can be in the same private scope
})();
And then...
Take a look at Rakefile provided with WysiHat to set the automated unit testing up. Nice stuff :)
And now for the answer
This does not answer the original question very well. I know and I'm sorry about that, but I've posted it here because I hope it may be useful to someone else to organize their mess.
My approach to the problem is to do as much object-oriented modelling I can and separate implementations into different files. Then the handlers should be as short as possible. The example with List singleton is also nice one.
And namespaces... well they can be imitated by deeper object structure.
if (typeof org === 'undefined') {
var org = {};
}
if (!org.hasOwnProperty('example')) {
org.example = {};
}
org.example.AnotherObject = function () {
// constructor body
};
I'm not big fan of imitations, but this can be helpful if you have many objects that you would like to move out of the global scope.
The code organization requires adoption of conventions and documentation standards:
1. Namespace code for a physical file;
Exc = {};
2. Group classes in these namespaces javascript;
3. Set Prototypes or related functions or classes for representing real-world objects;
Exc = {};
Exc.ui = {};
Exc.ui.maskedInput = function (mask) {
this.mask = mask;
...
};
Exc.ui.domTips = function (dom, tips) {
this.dom = gift;
this.tips = tips;
...
};
4. Set conventions to improve the code. For example, group all of its internal functions or methods in its class attribute of an object type.
Exc.ui.domTips = function (dom, tips) {
this.dom = gift;
this.tips = tips;
this.internal = {
widthEstimates: function (tips) {
...
}
formatTips: function () {
...
}
};
...
};
5. Make documentation of namespaces, classes, methods and variables. Where necessary also discuss some of the code (some FIs and Fors, they usually implement important logic of the code).
/**
* Namespace <i> Example </i> created to group other namespaces of the "Example".
*/
Exc = {};
/**
* Namespace <i> ui </i> created with the aim of grouping namespaces user interface.
*/
Exc.ui = {};
/**
* Class <i> maskdInput </i> used to add an input HTML formatting capabilities and validation of data and information.
* # Param {String} mask - mask validation of input data.
*/
Exc.ui.maskedInput = function (mask) {
this.mask = mask;
...
};
/**
* Class <i> domTips </i> used to add an HTML element the ability to present tips and information about its function or rule input etc..
* # Param {String} id - id of the HTML element.
* # Param {String} tips - tips on the element that will appear when the mouse is over the element whose identifier is id <i> </i>.
*/
Exc.ui.domTips = function (id, tips) {
this.domID = id;
this.tips = tips;
...
};
These are just some tips, but that has greatly helped in organizing the code. Remember you must have discipline to succeed!
Following good OO design principals and design patterns goes a long way to making your code easy to maintain and understand.
But one of the best things I've discovered recently are signals and slots aka publish/subscribe.
Have a look at http://markdotmeyer.blogspot.com/2008/09/jquery-publish-subscribe.html
for a simple jQuery implementation.
The idea is well used in other languages for GUI development. When something significant happens somewhere in your code you publish a global synthetic event which other methods in other objects may subscribe to.
This gives excellent separation of objects.
I think Dojo (and Prototype?) have a built in version of this technique.
see also What are signals and slots?
I was able to successfully apply the Javascript Module Pattern to an Ext JS application at my previous job. It provided a simple way to create nicely encapsulated code.
Dojo had the module system from the day one. In fact it is considered to be a cornerstone of Dojo, the glue that holds it all together:
dojo.require — the official doc.
Understanding dojo.declare, dojo.require, and dojo.provide.
Introducing Dojo.
Using modules Dojo achieves following objectives:
Namespaces for Dojo code and custom code (dojo.declare()) — do not pollute the global space, coexist with other libraries, and user's non-Dojo-aware code.
Loading modules synchronously or asynchronously by name (dojo.require()).
Custom builds by analyzing module dependencies to create a single file or a group of interdependent files (so-called layers) to include only what your web application needs. Custom builds can include Dojo modules and customer-supplied modules as well.
Transparent CDN-based access to Dojo and user's code. Both AOL and Google carry Dojo in this fashion, but some customers do that for their custom web applications as well.
Check out JavasciptMVC.
You can :
split up your code into model, view and controller layers.
compress all code into a single production file
auto-generate code
create and run unit tests
and lots more...
Best of all, it uses jQuery, so you can take advantage of other jQuery plugins too.
My boss still speaks of the times when they wrote modular code (C language), and complains about how crappy the code is nowadays! It is said that programmers can write assembly in any framework. There is always a strategy to overcome code organisation. The basic problem is with guys who treat java script as a toy and never try to learn it.
In my case, I write js files on a UI theme or application screen basis, with a proper init_screen(). Using proper id naming convention, I make sure that there are no name space conflicts at the root element level. In the unobstrusive window.load(), I tie the things up based on the top level id.
I strictly use java script closures and patterns to hide all private methods. After doing this, never faced a problem of conflicting properties/function definitions/variable definitions. However, when working with a team it is often difficult to enforce the same rigour.
I'm surprised no one mentioned MVC frameworks. I've been using Backbone.js to modularize and decouple my code, and it's been invaluable.
There are quite a few of these kinds of frameworks out there, and most of them are pretty tiny too. My personal opinion is that if you're going to be writing more than just a couple lines of jQuery for flashy UI stuff, or want a rich Ajax application, an MVC framework will make your life much easier.
"Write like crazy and just hope it works out for the best?", I've seen a project like this which was developed and maintained by just 2 developers, a huge application with lots of javascript code. On top of that there were different shortcuts for every possible jquery function you can think of. I suggested they organize the code as plugins, as that is the jquery equivalent of class, module, namespace... and the whole universe. But things got much worse, now they started writing plugins replacing every combination of 3 lines of code used in the project.
Personaly I think jQuery is the devil and it shouldn't be used on projects with lots of javascript because it encourages you to be lazy and not think of organizing code in any way. I'd rather read 100 lines of javascript than one line with 40 chained jQuery functions (I'm not kidding).
Contrary to popular belief it's very easy to organize javascript code in equivalents to namespaces and classes. That's what YUI and Dojo do. You can easily roll your own if you like. I find YUI's approach much better and efficient. But you usualy need a nice editor with support for snippets to compensate for YUI naming conventions if you want to write anything useful.
I create singletons for every thing I really do not need to instantiate several times on screen, a classes for everything else. And all of them are put in the same namespace in the same file. Everything is commented, and designed with UML , state diagrams. The javascript code is clear of html so no inline javascript and I tend to use jquery to minimize cross browser issues.
In my last project -Viajeros.com- I've used a combination of several techniques. I wouldn't know how to organize a web app -- Viajeros is a social networking site for travellers with well-defined sections, so it's kind of easy to separate the code for each area.
I use namespace simulation and lazy loading of modules according to the site section. On each page load I declare a "vjr" object, and always load a set of common functions to it (vjr.base.js). Then each HTML page decides which modules need with a simple:
vjr.Required = ["vjr.gallery", "vjr.comments", "vjr.favorites"];
Vjr.base.js gets each one gzipped from the server and executes them.
vjr.include(vjr.Required);
vjr.include = function(moduleList) {
if (!moduleList) return false;
for (var i = 0; i < moduleList.length; i++) {
if (moduleList[i]) {
$.ajax({
type: "GET", url: vjr.module2fileName(moduleList[i]), dataType: "script"
});
}
}
};
Every "module" has this structure:
vjr.comments = {}
vjr.comments.submitComment = function() { // do stuff }
vjr.comments.validateComment = function() { // do stuff }
// Handlers
vjr.comments.setUpUI = function() {
// Assign handlers to screen elements
}
vjr.comments.init = function () {
// initialize stuff
vjr.comments.setUpUI();
}
$(document).ready(vjr.comments.init);
Given my limited Javascript knowledge, I know there must be better ways to manage this, but until now it's working great for us.
Organising your code in a Jquery centric NameSpace way may look as follows... and will not clash with other Javascript API's like Prototype, Ext either.
<script src="jquery/1.3.2/jquery.js" type="text/javascript"></script>
<script type="text/javascript">
var AcmeJQ = jQuery.noConflict(true);
var Acme = {fn: function(){}};
(function($){
Acme.sayHi = function()
{
console.log('Hello');
};
Acme.sayBye = function()
{
console.log('Good Bye');
};
})(AcmeJQ);
// Usage
// Acme.sayHi();
// or
// Say Hello
</script>
Hope this helps.
Good principal of OO + MVC would definitely go a long way for managing a complex javascript app.
Basically I am organizing my app and javascript to the following familiar design (which exists all the way back from my desktop programming days to Web 2.0)
Description for the numeric values on the image:
Widgets representing the views of my application. This should be extensible and separated out neatly resulting good separation that MVC tries to achieve rather than turning my widget into a spaghetti code (equivalent in web app of putting a large block of Javascript directly in HTML). Each widget communicate via others by listening to the event generated by other widgets thus reducing the strong coupling between widgets that could lead to unmanageable code (remember the day of adding onclick everywhere pointing to a global functions in the script tag? Urgh...)
Object models representing the data that I want to populate in the widgets and passing back and forth to the server. By encapsulating the data to its model, the application becomes data format agnostics. For example: while Naturally in Javascript these object models are mostly serialized and deserialized into JSON, if somehow the server is using XML for communication, all I need to change is changing the serialization/deserialization layer and not necessarily needs to change all the widget classes.
Controller classes that manage the business logic and communication to the server + occasionally caching layer. This layer control the communication protocol to the server and put the necessary data into the object models
Classes are wrapped neatly in their corresponding namespaces. I am sure we all know how nasty global namespace could be in Javascript.
In the past, I would separate the files into its own js and use common practice to create OO principles in Javascript. The problem that I soon found that there are multiple ways to write JS OO and it's not necessarily that all team members have the same approach. As the team got larger (in my case more than 15 people), this gets complicated as there is no standard approach for Object Oriented Javascript. At the same time I don't want to write my own framework and repeat some of the work that I am sure smarter people than I have solved.
jQuery is incredibly nice as Javascript Framework and I love it, however as project gets bigger, I clearly need additional structure for my web app especially to facilitate standardize OO practice. For myself, after several experiments, I find that YUI3 Base and Widget (http://yuilibrary.com/yui/docs/widget/ and http://yuilibrary.com/yui/docs/base/index.html) infrastructure provides exactly what I need. Few reasons why I use them.
It provides Namespace support. A real need for OO and neat organization of your code
It support notion of classes and objects
It gives a standardize means to add instance variables to your class
It supports class extension neatly
It provides constructor and destructor
It provides render and event binding
It has base widget framework
Each widget now able to communicate to each other using standard event based model
Most importantly, it gives all the engineers an OO Standard for Javascript development
Contrary to many views, I don't necessarily have to choose between jQuery and YUI3. These two can peacefully co-exist. While YUI3 provides the necessary OO template for my complex web app, jQuery still provides my team with easy to use JS Abstraction that we all come to love and familiar with.
Using YUI3, I have managed to create MVC pattern by separating classes that extend the Base as the Model, classes that extends Widget as a View and off course you have Controller classes that are making necessary logic and server side calls.
Widget can communicate with each other using event based model and listening to the event and doing the necessary task based on predefined interface. Simply put, putting OO + MVC structure to JS is a joy for me.
Just a disclaimer, I don't work for Yahoo! and simply an architect that is trying to cope with the same issue that is posed by the original question. I think if anyone finds equivalent OO framework, this would work as well. Principally, this question applies to other technologies as well. Thank God for all the people who came up with OO Principles + MVC to make our programming days more manageable.
I use Dojo's package management (dojo.require and dojo.provide) and class system (dojo.declare which also allows for simple multiple inheritance) to modularize all of my classes/widgets into separate files. Not only dose this keep your code organized, but it also lets you do lazy/just in time loading of classes/widgets.
A few days ago, the guys at 37Signals released a RTE control, with a twist. They made a library that bundles javascript files using a sort of pre-processor commands.
I've been using it since to separate my JS files and then in the end merge them as one. That way I can separate concerns and, in the end, have only one file that goes through the pipe (gzipped, no less).
In your templates, check if you're in development mode, and include the separate files, and if in production, include the final one (which you'll have to "build" yourself).
Create fake classes, and make sure that anything that can be thrown into a separate function that makes sense is done so. Also make sure to comment a lot, and not to write spagghetti code, rather keeping it all in sections. For example, some nonsense code depicting my ideals. Obviously in real life I also write many libraries that basically encompass their functionality.
$(function(){
//Preload header images
$('a.rollover').preload();
//Create new datagrid
var dGrid = datagrid.init({width: 5, url: 'datalist.txt', style: 'aero'});
});
var datagrid = {
init: function(w, url, style){
//Rendering code goes here for style / width
//code etc
//Fetch data in
$.get(url, {}, function(data){
data = data.split('\n');
for(var i=0; i < data.length; i++){
//fetching data
}
})
},
refresh: function(deep){
//more functions etc.
}
};
Use inheritance patterns to organize large jQuery applications.
I think this ties into, perhaps, DDD (Domain-Driven Design). The application I'm working on, although lacking a formal API, does give hints of such by way of the server-side code (class/file names, etc). Armed with that, I created a top-level object as a container for the entire problem domain; then, I added namespaces in where needed:
var App;
(function()
{
App = new Domain( 'test' );
function Domain( id )
{
this.id = id;
this.echo = function echo( s )
{
alert( s );
}
return this;
}
})();
// separate file
(function(Domain)
{
Domain.Console = new Console();
function Console()
{
this.Log = function Log( s )
{
console.log( s );
}
return this;
}
})(App);
// implementation
App.Console.Log('foo');
For JavaScript organization been using the following
Folder for all your javascript
Page level javascript gets its' own file with the same name of the page. ProductDetail.aspx would be ProductDetail.js
Inside the javascript folder for library files I have a lib folder
Put related library functions in a lib folder that you want to use throughout your application.
Ajax is the only javascript that I move outside of the javascript folder and gets it's own folder. Then I add two sub folders client and server
Client folder gets all the .js files while server folder gets all the server side files.
I'm using this little thing. It gives you 'include' directive for both JS and HTML templates. It eleminates the mess completely.
https://github.com/gaperton/include.js/
$.include({
html: "my_template.html" // include template from file...
})
.define( function( _ ){ // define module...
_.exports = function widget( $this, a_data, a_events ){ // exporting function...
_.html.renderTo( $this, a_data ); // which expands template inside of $this.
$this.find( "#ok").click( a_events.on_click ); // throw event up to the caller...
$this.find( "#refresh").click( function(){
widget( $this, a_data, a_events ); // ...and update ourself. Yep, in that easy way.
});
}
});
You can use jquery mx (used in javascriptMVC) which is a set of scripts that allows you to use models, views, and controllers. I've used it in a project and helped me create structured javascript, with minimal script sizes because of compression. This is a controller example:
$.Controller.extend('Todos',{
".todo mouseover" : function( el, ev ) {
el.css("backgroundColor","red")
},
".todo mouseout" : function( el, ev ) {
el.css("backgroundColor","")
},
".create click" : function() {
this.find("ol").append("<li class='todo'>New Todo</li>");
}
})
new Todos($('#todos'));
You can also use only the controller side of jquerymx if you aren't interested in the view and model parts.
Your question is one that plagued me late last year. The difference - handing the code off to new developers who had never heard of private and public methods. I had to build something simple.
The end result was a small (around 1KB) framework that translates object literals into jQuery. The syntax is visually easier to scan, and if your js grows really large you can write reusable queries to find things like selectors used, loaded files, dependent functions, etc.
Posting a small framework here is impractical, so I wrote a blog post with examples (My first. That was an adventure!). You're welcome to take a look.
For any others here with a few minutes to check it out, I'd greatly appreciate feedback!
FireFox recommended since it supports toSource() for the object query example.
Cheers!
Adam
I use a custom script inspired by Ben Nolan's behaviour (I can't find a current link to this anymore, sadly) to store most of my event handlers. These event handlers are triggered by the elements className or Id, for example.
Example:
Behaviour.register({
'a.delete-post': function(element) {
element.observe('click', function(event) { ... });
},
'a.anotherlink': function(element) {
element.observe('click', function(event) { ... });
}
});
I like to include most of my Javascript libraries on the fly, except the ones that contain global behaviour. I use Zend Framework's headScript() placeholder helper for this, but you can also use javascript to load other scripts on the fly with Ajile for example.
You don't mention what your server-side language is. Or, more pertinently, what framework you are using -- if any -- on the server-side.
IME, I organise things on the server-side and let it all shake out onto the web page. The framework is given the task of organising not only JS that every page has to load, but also JS fragments that work with generated markup. Such fragments you don't usually want emitted more than once - which is why they are abstracted into the framework for that code to look after that problem. :-)
For end-pages that have to emit their own JS, I usually find that there is a logical structure in the generated markup. Such localised JS can often be assembled at the start and/or end of such a structure.
Note that none of this absolves you from writing efficient JavaScript! :-)
Lazy Load the code you need on demand. Google does something like this with their google.loader
Related
So I have been making a web app in the qooxdoo framework that utilised the d3 library. At the moment, every function which needs to use the d3 library works like this:
myFunction : function() {
var req = new qx.bom.request.Script();
req.onload = this.myActualFunction(); //calls function when script loads
req.open("GET","http://d3js.org/d3.v3.js" );
req.send();
}
It seems verbose to have to call the script loader for lots of different functions*. We could, and eventually probably will, switch to using d3 from a local directory. Nevertheless, it seems like there are lots of times when you would like to use a script loader to make a script available to, say, every member function of an object. Is there someway that I can achieve that? If I passed the script loader around like a variable, does that mean that every function which has it in scope gets access to the library?
The Manual did not appear very helpful on this topic.
*I presume that qooxdoo arranges to cache the script - it seems to be pretty good at those type of optimisations, though I have no specific knowledge of how the script loaders are treated in the compiled version.
The best approach of handling an external library is to create a Qooxdoo wrapper which will be a first-class citizen in the dependency management process. Qooxdoo internally makes use of this approach, e.g. Sizzle, Mustache, etc. Luckily for you there's already a contribution for D3. Though you can make your own wrapper without a hassle.
You can also, use add-script to "link" the library to the document but I see this way mostly disadvantageous.
I'm using the latest qooxdoo SDK (3.5) and am trying to find a way to dynamically load a module. Each module would implement an "init" function which creates a window in the application and, from that point, is self-contained.
What I would need is the ability to call an arbitrary init function without knowing the module existed beforehand. For example, someone uploads a custom module and tries to run it--I just need to call the module's init function (or error out if the call fails).
Any ideas?
Edit:
Something like:
function loadModule(modName) {
var mod = new qx.something.loadModule(modName);
mod.init();
}
I found 3 ways that Qooxdoo has to run dynamic code. The first way is via the built-in parts loader. "Parts" are basically portions of an application that qooxdoo will load "just-in-time" when you actually need them--for example, a class that operates a rarely used form or dialog box. This method is not truly dynamic (in my opinion) in that it requires the code to be included in the build process that Qooxdoo provides. Explaining exactly how it works is out of scope for this answer and, frankly, I'm not yet all that familiar with it myself.
The second way is via the qx.Class.getByName() function call. It works like so:
qx.Class.define("Bacon", {
extend: qx.core.Object,
construct: function(foo, bar) {
this.foo = foo;
this.bar = bar;
}
});
var klass = qx.Class.getByName("Bacon");
var obj = new klass("foo", "bar");
this.debug(obj.foo);
This method was found on the Qooxdoo mailing list here. This method will work for code included in the build process and for code introduced dynamically but, in my opinion, is trumped by the third method for the simple reason that if you are introducing a new class dynamically, you'll have to use the third method anyway.
The final method I located was actually revealed to me via studying the source code for the Qooxdoo playground. (The source code is available as part of the desktop download.)
The playground reads the code in from the editor and creates an anonymous function out of it, then executes the function. There is a bunch of setup and tear-down the playground does surrounding the following code, but I've removed it for brevity and clarity. If you are interested in doing something similar yourself, I highly recommend viewing the source code for the playground application. The dynamic code execution is contained within the __updatePlayground function starting on line 810 (Qooxdoo v3.5).
var fun;
try {
fun = qx.event.GlobalError.observeMethod(new Function(code));
} catch(ex) {
//do something with the exception
}
try {
fun.call();
} catch(ex) {
//do something with the exception
}
The code is straightforward and uses the built-in Javascript function "call" to execute the anonymous function.
Please define module.
Qooxdoo source code uses the same convention as Java - one class per file. Do you really want to load classes individually and deal with dependencies? If not, what's your definition of a module?
Other than that, qooxdoo has a notion of packages, which are groups of classes, interfaces and mixins, framework, contribs, including the framework itself, packed by the generator in an optimized way, so that the classes used earlier are loaded earlier. Using qooxdoo's own packaging mechanism requires no more effort than running build with custom arguments or customizing the config.json - all described in detail in the manual.
If your idea of a module is sort of a sub-application, mostly decoupled from everything else in the big application, I'm not sure it's achievable without either significantly modifying the generator code (what ./generate.py calls) or accepting some size overhead.
I won't go into details of modifying the generator - if you go this route you'll need to dig deeply anyway, and you'll learn more than I know about the generator.
What you can do while staying within what qooxdoo allows is to create a separate island application for each module, build your own infrastructure for inter-modules communication via JavaScript attached to the top window, and run the modules inside the main page, with some manually added magic to make the various modules behave like tab panes or qooxdoo windows. The overhead you'll have to take, besides some awkward custom, non-qooxdoo code, is that all modules will re-load the qooxdoo framework code.
Hi has any one used google's Closure Library https://developers.google.com/closure/ in building Phonegap applications on Android. I have read that Closure has good support for internationalization of applications. So if anyone could provide material they referred or sample snippets to get an idea of how to implement it.
There is no difference as to how you use PhoneGap. Framing a web view inside a native app background, doesn't change.
The Closure Library, unlike any other library, will compile your javascript to raw heavily minified code with semantic features.
otherwise yes, use it as you please, PhoneGap included.
When you build something with Closure, you can render the DOM in JavaScript. It is super fast and much much better than the conventional way.
so you create your pages with goog.dom.createDom. Below you will find an example.
var menuButton = goog.dom.createDom('a', {
'class': 'menu-button',
'otherAttributes': 'otherValues etc'
}, myproject.translations.menuButton.currentLanguage);
//Now you have a file like this:
goog.provide('myproject.translations');
// Language variations corresponding to that element.
myproject.translations.menuButton = {
'EN': 'go',
'FR': 'aller',
'DE': 'gehen'//etc...
};
Do the above wherever translations are needed. Then simply set the current language on load with something very easy like.
myproject.boot = function(parameters) {
myproject.translations.currentLanguage = parameters['currentLanguage'];
};
goog.exportSymbol('myproject.boot', myproject.boot);
and then call the boot method inside the index.php or whatever on window.load and echo a JSON string with the boot parameters from the server. Beware, everything that comes from the server must be encapsulated within quotes when referenced. Otherwise the compiler will flatten the property name in ADVANCED_OPTIMIZATIONS mode.
I've been playing with node.js for a while, and I've really come to appreciate how awesome it is. However, one thing I'm struggling to understand is how I should structure my code so that it is maintainable. Most tutorials I've seen on the internet have all the JS in one file, which is hardly a nice way to manage your code. I am aware there is no such thing in real-terms as a "class" in javascript, but is there a (standard) way for me to format my code for maintainability in the same way I'd structure a PHP project, for example?
I'd add that as far as maintainability goes, I believe the typical style of deeply-nesting callbacks using closures is the single greatest impediment to the understandability of Node programs, as well as being completely unnecessary.
For every:
a.doSomething(val, function(err,result){
b.doSomethingElse(result,function(err,res){
...
});
});
There is always a:
a.doSomething(val, onDoSomething);
function onDoSomething(err,res) {
...
}
My rule of thumb is: a new non-closure callback function is required for anything over three levels of nesting.
(Node.js really needs a style manual.)
Afaik you can use require to include your own js files (containing exported methods) using:
var req = require('./someJsFile');
Within someJsFile.js you can export methods like this:
exports.someMethod = function(){ /*...*/ };
And in your main file you can address such a method using req.someMethod()
So this way you can split up your code in different files, which you require from some central js file.
Here is an article explaining node.js require
After you learned how require works in node.js (pretty straightforward), as suggested by Kooilnc
You can take a look at the source code of the modules available for Node.js:
https://github.com/joyent/node/wiki/modules
If you're planning to use Express (one of the most robust node.js framework out there) to develop your first node applications, you can take a look at its specific samples here:
https://github.com/visionmedia/express/tree/master/examples
(there's also an mvc sample)
I'm in the process of moving a JSF heavy web application to a REST and mainly JS module application .
I've watched "scalable javascript application architecture" by Nicholas Zakas on YUI theater (excellent video) and I implemented much of the talk with good success, but I have some questions:
I found the lecture a little confusing in regards to the relationship between modules and sandboxes, on one hand, to my understanding, modules should not be affected by something happening outside of their sandbox and this is why they publish events via the sandbox (and not via the core, since the core is for hiding the base library) but each module in the application gets a new sandbox? Shouldn't the sandbox limit events to the modules using it or should events be published cross page? e.g. : if I have two editable tables but I want to contain each one in a different sandbox and its events affect only the modules inside that sandbox, something like message box per table which is a different module/widget, how can I do that with sandbox per module, of course I can prefix the events with the moduleid but that creates coupling that I want to avoid ... and I don't want to package modules together as one module per combination as I already have 6-7 modules.
While I can hide the base library for small things like id selector etc.. I would still like to use the base library for module dependencies and resource loading and use something like YUI loader or dojo.require so in fact I'm hiding the base library but the modules themselves are defined and loaded by the base library ... seems a little strange to me.
libraries don't return simple js objects but usually wrap them e.g. : You can do something like $$('.classname').each(.. which cleans the code a lot, it makes no sense to wrap the base and then in the module create a dependency for the base library by executing .each but not using those features makes a lot of code written which can be left out ... and implementing that functionality is very bug prone.
Does anyone have any experience with building a front side stack of this order? How easy is it to change a base library and/or have modules from different libraries, using yui datatable but doing form validation with dojo ... ?
Somewhat of a combination of 2+4 if you choose to do something like I said and load dojo form validation widgets for inputs via YUI loader would that mean dojocore is a module and the form module is dependent on it?
We use this pattern heavily in our applications. Check out the book JavaScript Patterns by Stoyan Stefanov for a detailed look in how to implement the Sandbox pattern. Basically it looks something like this:
(function (global) {
var Sandbox = function fn (modules, callback) {
var installedModules = Sandbox.modules,
i = 0,
len = modules.length;
if (!(this instanceof fn)) {
return new fn(modules, callback);
}
// modules is an array in this instance:
for (; i < len; i++) {
installedModules[modules[i]](this);
}
callback(this);
};
Sandbox.modules = {};
global.Sandbox = Sandbox;
})(this);
// Example module:
// You extend the current sandbox instance with new functions
Sandbox.modules.ajax = function(sandbox) {
sandbox.ajax = $.ajax;
sandbox.json = $.getJSON;
};
// Example of running your code in the sandbox on some page:
Sandbox(['ajax'], function(sandbox) {
sandbox.ajax({
type: 'post',
url: '/Sample/Url',
success: function(response) {
// success code here. remember this ajax maps back to $.ajax
}
});
});