JavaScript Advanced Programming: Chapter I.

Introduction to JavaScript:

The 1.JavaScript implementation should consist of the following three parts:

(1) Core: ECMAScript

(2) Document Object model: DOM

(3) Browser object model: BOM

2. What is ECMAScript compatible:

(1) supports all "types, values, objects, attributes, functions, and program syntax and Semantics" described by ECMA-262.

(2) Support Unicode character standard.

(3) Add "more types, values, objects, properties, and functions" that are not described by ECMA-262.

(4) Support ECMA-262 not defined

3. Document Object Model (DOM)

1. The Document Object model is an application programming interface (API) for XML but extended for HTML. The DOM maps the entire page to the structure of a multi-tiered node.

2.DOM level

(1) DOM1 level: The DOM core specifies how to map an XML-based document structure to simplify access and manipulation of any part of the document. Dom HTML modules are expanded on the basis of the DOM core, adding objects and methods for HTML.

(2) DOM2 level in the original DOM based on the expansion of the mouse and user interface events, scopes, traversal and other westerly modules, and through the object interface to increase the support for CSS.

(3) The DOM3 level further expands the DOM, introducing a way to load and save documents in a uniform manner-defined in DOM loading and saving modules, and new methods for validating documents-defined in the DOM validation module.

(4) Other DOM standards: SVG (Scalable vector graph), MathML (mathematical Markup Language), SMIL (Synchronous Multimedia Integration language).

3. Browser object Model (BOM)

Fundamentally, the BOM only handles browser windows and frames, but it's customary to count all browser-specific JavaScript extensions as part of the BOM, and here's the extension:

(1) The function of popup new browser window;

(2) Navigator object that provides detailed information about the browser;

(3) A Location object that provides detailed information about the page loaded by the browser;

(4) Screen object providing detailed information of user's display resolution;

(5) Support for cookies;

(6) Custom objects such as the activexobject of XMLHttpRequest and IE.

JavaScript Advanced Programming: Chapter I.