JooseX.Namespace.Depended - a cross-platform (browser/NodeJS), asynchronous, 100% compatible with <script> tags dependencies handling, integrated with Joose3
Setup for browsers (see Joose installation notes):
<!-- Joose ->
<script type="text/javascript" src="/jsan/Task/Joose/Core.js"></script>
<!-- JooseX.Namespace.Depended - web-specific files only ->
<script type="text/javascript" src="/jsan/Task/JooseX/Namespace/Depended/Web.js"></script>
<!-- or ->
<!-- JooseX.Namespace.Depended - cross-platform bundle ->
<script type="text/javascript" src="/jsan/Task/JooseX/Namespace/Depended/Auto.js"></script>
<script type="text/javascript">
use.paths = [ 'lib', '/jsan' ]
</script>
Setup for NodeJS:
// this extension is bundled into the following package
require('task-joose-nodejs')
Declare dependencies in various class builders:
Class('Some.Class', {
VERSION : 0.02,
meta : 'My.Meta',
isa : 'Super.Class',
does : {
'Some.Role' : 0.01,
'Some.Other.Role' : 0.02
},
trait : 'Some.Trait',
has : {
attr : {
meta : 'Attribute.Meta',
trait : 'Attribute.Trait',
is : 'rw'
}
},
use : [ 'Cant.Get.Enough' ],
body : function (module) {
// All dependencies will be loaded here
}})
// 'Some.Class' is still fetching dependencies here, too early to instantiate it
Or load them on-demand from code:
use({ 'Some.Class' : 0.01 }, function () {
// Some.Class and all its dependencies are ready
var obj = new Some.Class()
})
JooseX.Namespace.Depended is a cross-platform (browsers/NodeJS) dependencies handling framework, tightly integrated with Joose3.
It allows you to refer to other (not yet loaded) classes/roles in your class declaration. Those classes will be loaded prior your class declaration. All edge cases like referring to already loaded class, double loading, etc are handled correctly.
If you are reading this file as README from github, you may want to open this link instead.
All dependencies should be specified with the dependency descriptors. In the simplest case, the descriptor is just a plain string with the name of class:
'MyApp.Widget.Header'
In more complex case, the descriptor is an object, which keys are classes names and values - their's versions:
{
'MyApp.Widget.Header' : 0.03,
'MyApp.Util.Helper' : 0.01
}
Such descriptors can contain several dependencies, though they are limited to Joose classes only.
In general case, the dependency descriptor is an object with the following structure:
{
type : 'joose',
token : 'MyApp.Widget.Header',
version : 0.03
}
Such descriptor can contain exactly one dependency, with the resource of any type.
See also delayed dependencies.
General rule is - whereever in your class declaration you can refer to other class (for example in the does builder) - you can specify the
dependency descriptor instead.
This means, that you can specify the dependencies in:
- `meta` builder (!)
- `isa` builder
- `trait` builder
- `does` builder
- `meta/trait` parameters of attributes
For example this declaration is perfectly valid:
Class('Some.Class', {
meta : 'My.Meta',
isa : 'Super.Class',
does : {
'Some.Role' : 0.01,
'Some.Other.Role' : 0.02
},
trait : 'Some.Trait',
has : {
attr : {
meta : 'Attribute.Meta',
trait : 'Attribute.Trait',
is : 'rw'
}
}
...
})
Also in any other custom builder (some authoring required)
The framework will scan class declaration for dependencies, pre-load them, then substitute descriptors with actual classes and continue the declaration process.
use builderAdditionaly, you can provide an array of dependencies (or a single dependency) in the use builder:
Class('Some.Class', {
use : [ 'Some.Other.Class', 'Some.Other.Role' ],
...
})
This framework behaves totally asynchronously, so pay attention to the following notes.
The dependencies of the class won't be available immediately after class declaration:
Class('Some.Class', {
isa : 'Super.Class',
does : {
'Some.Role' : 0.01
}
})
// kaboom! - 'Super.Class' and 'Some.Role' are not yet loaded at this point
var a = new Some.Class
Dependencies will be available in the body builder of the class:
Class('Some.Class', {
isa : 'Super.Class',
does : {
'Some.Role' : 0.01
},
body : function () {
// ok
var a = new Some.Class()
}})
In general, for example if you've included some class with <script> tag, and that class has declared but not yet loaded dependencies,
wrap the usage of the class with use from code (see below).
use from codeYou can also load the dependencies from code:
use([ 'Some.Class1', 'Some.Class2' ], function () {
var a = new Some.Class1()
var b = new Some.Class2()
})
The class name you are refering to, will be converted to file name using this simple scheme:
class name: MyClass
file name: MyClass.js
class name: Some.Class
file name: Some/Class.js
class name: Some.Other.Class
file name: Some/Other/Class.js
Generally each dot is replaced with directory separator, and the 'js' extension is appended to result
The framework will look up the classes in several libraries, which are just the directories, containing the source files.
The current list of libraries is stored as an array in: use.paths (on NodeJS platform its just an alias of require.paths). Default value is:
use.paths = [ 'lib', '/jsan' ]
You can freely modify this value, however it will be a good idea to use only methods of array, which mutates it in-place.
For example, if you are running a test harness, as t/index.html, and would like to refer
to your files, which are in lib/, you'll need to add the ../lib entry with:
use.paths.unshift('../lib')
Framework will scan through the libraries list sequentially and attempt to load the class from every entry. Class will be loaded from the first library, which contains the corresponded file. If there are no such file, loading will continue to another entry.
For example, if we are loading class Some.Class, and we have the default setting for libraries, then first it will be tried to load with the following URL:
lib/Some/Class.js
If there are no such file, the 2nd entry will be tried:
/jsan/Some/Class.js
If there are no such file again, the exception will be thrown.
This package adds a new attribute initializer: Joose.I.FutureClass
It can be used, when the default value of the attribute should be set to the constructor of some class, which may be not yet loaded on the declaration stage:
Class('MyApp.Widget.Template', {
use : 'MyApp.Util.Helper',
has : {
helperClass : Joose.I.FutureClass('MyApp.Util.Helper')
}
})
You can also specify a "delayed" dependency descriptors, using the attribute helper:
Class('Some.Class', {
use : 'Task.Some.Bundle',
does : Joose.I.FutureClass('Some.Role.From.Bundle')
})
or just an arbitrary function (function shouldn't has a meta property):
Class('Some.Class', {
use : 'Task.Some.Bundle',
does : function () { return Some.Role.From.Bundle }
})
The framework won't attempt to load such descriptors. Instead, the provided function will called before class construction (when other "real dependencies" were already loaded). Function is supposed to return a class (or role) which will be used as part of the class declaration.
This feature is useful for example, when you'd like to depend from a file, containing definitions of several roles, and you'd like to use those roles in your class.
To load non-joose code, specify the descriptor with the 'javascript' type and with url to the source in token, as follows:
{
type : 'javascript',
token : 'MyApp/Widget/Header.js',
presence : function () {
return MyApp.Widget.Header
}
}
Note the presence field. presence is function which should return true value, if the
resource is already presented in the scope (for example has been loaded with the <script> tag). In such case,
the loading of resource will be skipped. presence can be specified as string, which will be evaled (exceptions are caught).
type : 'javascript' is optional if token contains "/" or ends with ".js". So, the descriptor above
could be also written as:
{
token : 'MyApp/Widget/Header.js',
presence : 'MyApp.Widget.Header'
}
If the url in token is relative, then the it will prepended with paths from use.paths (each path will be checked, sequentially).
If the url is absolute (starts with "/" or "http://") or starts with "=" then it will be used directly and use.paths will be ignored:
{
token : '=MyApp/Widget/Header.js', // ignore `use.path` settings
presence : 'MyApp.Widget.Header'
}
Also, when specifying the descriptor as string, the type of the descriptor will be switched to 'javascript' if it contains the "/" or ends with ".js":
use('http://ajax.googleapis.com/ajax/libs/ext-core/3.1.0/ext-core.js', function () {
...
})
The code above will load "ext-core" library. However, currently there is no way to specify the presence attribute in such descriptor
and no checks will be performed prior loading (potentially allowing repeated loading). This may change in future versions.
JooseX.Namespace.Depended is 100% compatible with <script> tag loading and files concatenation. Some notes:
presence when loading non-joose code to avoid double-loading.Additionally, if you will concatenate your JS files in the single file in the correct order (which is not required(!))
you'll receive a synchronous execution of the whole file (no setTimeout delays).
When debugging the code, loaded with JooseX.Namespace.Depended in FireBug, switch to the "Show Static and eval Scripts" option on the Scripts panel (2nd button from on the toolbar, probably "static"). Also make sure, the "Decompile for eval() sources" option is unchecked otherwise Firebug will re-format your sources.
By default, JooseX.Namespace.Depended will fetch the source files with asynchronous XHR request and execute it with "eval".
You may want to change this behavior, for example switch to using <script> tags for loading & execution (unreliable in IE):
<script type="text/javascript" src="/jsan/Task/JooseX/Namespace/Depended/Web.js"></script>
<script type="text/javascript">
JooseX.Namespace.Depended.Resource.JavaScript.meta.extend({
doesnt : [ JooseX.Namespace.Depended.Transport.XHRAsync, JooseX.Namespace.Depended.Materialize.Eval ],
does : JooseX.Namespace.Depended.Transport.ScriptTag
})
use.paths = [ 'lib', '/jsan' ]
</script>
When using this framework on NodeJS platform, the use.paths will be an alias of require.paths.
For additional information, please refer to the documentation of the Task.Joose.NodeJS
Framework is highly customizable, additional resources/transport/materialization modes can be easily added. Please refer to JooseX.Namespace.Depended.Authoring for more information.
This framework can operate in special mode, in which it can load any class, with any number of dependencies (in-depth), with 2 http requests.
For more information about this mode please refer to http://www.extjs.com/forum/showthread.php?t=69161
This item is currently in TODO list.
This extension is supported via github issues tracker: http://github.com/SamuraiJack/JooseX-Namespace-Depended/issues
For general Joose questions you can also visit #joose on freenode or the mailing list at http://groups.google.com/group/joose-js
Base resource class: JooseX.Namespace.Depended.Resource
Web page of this module: http://github.com/SamuraiJack/JooseX-Namespace-Depended/
General documentation for Joose: http://joose.github.com/Joose/
All complex software has bugs lurking in it, and this module is no exception.
Please report any bugs through the web interface at http://github.com/SamuraiJack/JooseX-Namespace-Depended/issues
Nickolay Platonov nplatonov@cpan.org
Copyright (c) 2010, Nickolay Platonov
All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.