Ajax architecture of the Dojo chapter _dojo

Author: hopesoft
Source: http://www.51ajax.com

First, the preface
Since last year, Ajax has become a focus of technical hot spots, various AJAX frameworks developed rapidly, which is divided into client AJAX architecture, server-side AJAX architecture, which dojotoolkit as a good client Ajax architecture, more and more people are concerned about, learning. Since last year, Ajax has become a focus of technical hot spots, various AJAX frameworks developed rapidly, which is divided into client AJAX architecture, server-side AJAX architecture, which dojotoolkit as a good client Ajax architecture, more and more people are concerned about, learning.

Second, Dojo Introduction

As one of the early Open-source Ajax architectures, Dojo began in September 2004, with Http://www.dojotoolkit.org, led by Alex Russell of JotSpot.

Dojo is an open source JavaScript toolkit that has a lot of modules in it, and it enables complete lightweight window components and many features. The Dojo package loading mechanism (Package system) enables dynamic loading of required modules, and allows users to write their own Dojo extension modules with great flexibility.

Third, technical characteristics

1. Document structure

The current highest version of Dojo is 0.3.1, which consists primarily of a core code file (Dojo.js) that contains the main functionality and a number of JavaScript files. The required modules can be loaded dynamically according to the package mechanism when used.

Depending on the core code that contains the module, it is subdivided into the following versions:
· Ajax version: You can create an AJAX application that integrates complex visual effects and uses event modules.
· Widget version: includes the ability to implement loosely coupled HTML and CSS templates with small devices, providing clearly separated styles, content, and logic.
· event and I/O version: Includes incident module and I/O module
· Event version: Including events module
· Kitchen Sink Version: This version includes the entire collection of tools

The above versions are suitable for different occasions. Users can also reconstruct their own core code files according to their own needs, and only include their own common modules to avoid frequent dynamic loading of commonly used modules.

2. Program Structure

In the official dojo definition, Dojo is called Toolkit (the Toolkit), not the framework (just part of the framework), nor the library (plus a layer of encapsulation system on top of the library). Dojo includes language extensions for JavaScript itself, as well as various aspects of the tool class library, and a more complete library of UI components.

The following figure: (Original address http://manual.dojotoolkit.org/WikiHome/DojoDotBook/Book16)

As can be seen from the diagram, Dojo's design structure is very reasonable, and very scalable, can continuously add new features, and ensure the efficient operation of the program.

IV. Official Resources

Dojo's official website has the following resources to help us quickly familiarize ourselves with the architecture of dojo, and of course, because dojo has a wealth of functionality, it needs to be mastered in actual development.

1. Dojo Manual (The Dojo Manual)
URL: http://manual.dojotoolkit.org/
Systematically introduce the dojo mechanism, use methods, sample code, etc.

2. Dojo Mailing List (The Dojo mailing Lists)
You can discuss the issues that you encounter in using Dojo, or suggestions that you want to improve
Application Add: Http://dojotoolkit.org/mailman/listinfo/dojo-interest
View Archive: Http://news.gmane.org/gmane.comp.web.dojo.user

3. Dojo Error Tracking System (Bug tracking)
URL: http://trac.dojotoolkit.org/
can be submitted to effectively find bugs and submit bugs so that you can eliminate bugs in dojo in a timely manner

4. Code Warehouse (The Dojo Subversion Repository)
URL: Http://trac.dojotoolkit.org/browser
It's easy to get the latest version of the Dojo package

5. The Dojo Wiki
URL: http://dojo.jot.com/
The dojo Wiki is relatively rich in content categories, covering all aspects of dojo.

6. Irc
Chat Room Address: irc.freenode.net

7. Demo program included with the Dojo package
Provides 8 categories of nearly 30 demo programs, you can learn more quickly in practice dojo usage.

Tip: It is recommended to join Dojo's mailing list and study the sample code so that you can learn more quickly how dojo is used.

V. Development prospects

1. Technical level
Compared to other Ajax frameworks, the Package system and modular (libraries) architecture of the dojo design allows for better scalability, improved performance, reduced user development workload, and flexibility (users can write their own extensions).

2. Market level
Dojo is now a fast-growing, widely supported and founded Dojo Foundation, and the Open-source teams of IBM, AOL, Sun, and WebWork, Tapestry, open Laszlo are members of the Dojo Foundation, Strong backing to ensure that the dojo can continue to develop.

3. Development team
Under the leadership of Alex Russell, the Dojo development team has a strong development capability that we can see from the features, quality, and speed of the update available from the current release. In addition, Dojo will release 0.4.0 in the near future.

4. User groups
Thanks to the excellent design of dojo, a growing number of AJAX experts and novices have joined Dojo's developers, and these developers will also be able to develop the dojo accordingly.

5. Learning Resources
The Official Dojo website has a wealth of learning resources (see the "Official Resources" section) to help people master dojo more quickly and reduce the cost of learning.

Six, the conclusion

Dojo can help developers develop large AJAX projects and help build robust code that saves development time. The strong backing behind Dojo can also be a constant complement to the new features that help us get out of the low-level repetitive work and focus on developing on this basis.