JavaScript DOM (1)

A Brief History of JavaScript

JavaScript was developed by Netscape Company in collaboration with Sun Corporation. When JavaScript 1.0 was released, Netscape Navigator dominated the browser market. Microsoft released its VBScript language when it launched the IE3, and released a version of JavaScript in the name of JScript, quickly catching up with Netscape's pace. In the face of Microsoft's competition, Netscape and Sun's joint ECMA (European Computer Manufacturers Association) standardized the JavaScript language, and the ECMAScript language appeared, another name for the same language.

The DOM is a set of methods for abstracting and conceptualizing the contents of a document. Netscape Navigator 4 was released in June 1997, IE4 released in the same year October. Both browsers have made a lot of improvements to their earlier versions, greatly expanding the DOM, and making the functionality that can be done with javascript much greater. and web designers are beginning to come into contact with a term: DHTML (Dynamic HTML).

DHTML is not a new technology, but a term that describes the combination of HTML, CSS, and JavaScript technology. Unfortunately, the NN 4 and IE 4 browsers use two incompatible DOM types. This leads to a ridiculous situation where programmers have to know which browser environment they will run in when writing Dom script code, so in actual work, many scripts have to be written two times, one for Netscape Navigator and another for IE. At the same time, programmers must write some code to discover exactly which browser is running on the client. DHTML opens up a new world full of opportunities, but the people who want to get into it find it a world full of misery. So, not long ago, the evaluation of this technology became a "propaganda stunt" and "difficult to achieve".

At the same time that browser makers are using DOM as a weapon to launch a marketing war, the company has introduced a standardized DOM with the benefits of everyone. Thankfully, Netscape, Microsoft, and other browser makers have been able to set new standards with the company by setting aside their hostility, and completed the "1th Level dom" (DOM levels 1) in October 1998.

The definition of the DOM is: "An interface that is independent of the system platform and programming language, where programs and scripts can dynamically access and modify the content, structure, and style of the document." "The standardized DOM introduced by the World Wide Web, in terms of independence and scope of application, is far beyond the proprietary DOM that fighting each other's browser makers have introduced."

Today, almost all browsers have built-in support for DOM. We've seen the craze for learning Dom scripting, triggered by asynchronous data transfer Technology (AJAX), and the many new features of HTML5 DOM, how can people not be so imaginative about the future of the Web?

-- summary of the JavaScript DOM Programming Technology (2nd edition) Chapter I.

JavaScript DOM (1)