Introduction to "reading" Elevation 3-javascript

It mainly describes what JavaScript is and what parts it consists of.

History

Omitted...

JavaScript implementation

Javascript
ECMAScript	Dom	Bom

• Core (ECMAScript)
• Document Object Model (DOM)
• Browser object Model (BOM)

ECMAScript

Mainly the language description, version iteration quickly ES6 document good long look slowly.

Document Object Model (DOM)

The DOM is an application programming interface (API) for XML but extended for HTML. The DOM maps the entire page into a multi-tiered node structure.

With the API provided by the DOM, developers can easily delete, add, replace, or modify any node to control the structure and content of the page.

DOM level DOM1 level

Consists of two modules: the DOM core and Dom HTML.

• The Dom Core specifies how to map an XML-based document structure to simplify access and manipulation of any part of the document. is now extended to support XML namespaces.
• The domhtml module expands on the core of the DOM, adding objects and methods for HTML.

　　Note: Dom is not just for JavaScript, but also for many other languages. In Web browsers, the DOM based on the ECMAScript implementation has become an important part of the JS language.

DOM2 class

Based on the original DOM, the following new modules are expanded:

• Dom View (DOM views): Defines an interface for tracking different document views;
• DOM Event (DOM events): Defines the interface for event and event handling;
• Dom Style: Defines the interface in which CSS applies styles to elements;
• DOM Traversal and scope (DOM Traveral): Defines the interfaces that traverse and manipulate the document tree.

DOM3 class

The DOM3 class further expands the DOM, introducing the

• Dom loading and saving (Domload and Save): Defines methods for loading and saving documents in a uniform manner;
• Dom Validation (DOM Validation): New ways to validate documents.

The DOM3 level also extends the DOM core, starting with support for XML1.0, involving XML Infoset, XPath, and XML Base.

　　Note: TheDOMLevel 0 standard does not exist, only a reference point in historical coordinates.

Web browser support for Dom

This book has been written for several years, web development in recent years very fast, you can try the links behind the check. https://caniuse.com/#search =dom

Other DOM Standards

• SVG (Scalable Vector Graphic scalable vectors)
• MathML (mathematical Markup Language Mathematical Markup Language)
• SMIL (Synchronized Multimedia integration Language synchronized Multimedia integrated language)

Browser object Model (BOM)

Fundamentally, the BOM only handles browser windows and frames, but it is customary to count all browser-specific JS extensions as part of the BOM. Here are some of these extensions:

• Pop-up new browser window
• Move, zoom, and close the browser window
• Navigator object that provides browser details
• Location object that provides detailed information about the page loaded by the browser
• Screen object that provides detailed information about the user's display resolution
• Support for Cookies
• Custom objects such as the activexobject of XMLHttpRequest and IE

Introduction to "reading" Elevation 3-javascript