Web page making beginners See: Understanding the differences between XHTML DHTML sHTML

dhtml|xhtml| Beginner | difference | Web page

We often see these three things on a technical website or BBS: XHTML DHTML SHTML, what the hell is going on with them? Let's look at the explanations and explanations below.

XHTML:

HTML is a basic Web page design language, XHTML is an xml-based markup language, it looks like HTML, there are some small but important differences, XHTML is a role like HTML to play the XML, so, essentially speaking, XHTML is a transition technology that combines the powerful features of XML (in some cases) with the simplicity of HTML (most).

At the end of 2000, the International World Wide Web Consortium announced the release of the XHTML 1.0 version. XHTML 1.0 is a new language that is optimized and improved on the basis of HTML 4.0, and is designed to be based on XML applications. XHTML is an enhanced HTML, and its scalability and flexibility will accommodate more requirements for future network applications. The following is a common basic question about XHTML that is answered by Steven Pemberton, chairman of the HTML Working Group of the Consortium.

(1) XHTML solves the problem that the HTML language exists which seriously restricts its development. The HTML development to today exists three main disadvantages: can not adapt to the more network equipment and application needs, such as mobile phones, PDAs, information appliances can not directly display HTML; Because the HTML code is not specification, bloated, the browser needs to be smart enough and large to display the HTML correctly, data and performance mixed, If you want to change the display of your page, you must make the HTML again. So the HTML needs to evolve to solve the problem, and the xhtml,xhtml is a bridge over HTML to XML.

(2) XML is the trend of web development, so people are eager to join the trend of XML. XHTML is the current standard for replacing HTML4 markup languages, and with XHTML 1.0, you can design pages that fit both the XML system and most of the current HTML browsers as long as you follow some simple rules carefully. This means that you can design XML right away without waiting for people to use browsers that support XML. This guideline enables a smooth transition of the Web to XML.

(3) Another advantage of using XHTML is that it is very tight. The bad situation of HTML on the current network is shocking, the early browsers accept private HTML tags, so people have to use a variety of browsers to detect the page after the page design, to see whether it is compatible, there are often many inexplicable differences, people have to modify the design to adapt to different browsers.

(4) XHTML is able to interact well with other xml-based markup languages, applications, and protocols.

(5) XHTML is part of the Web Standard family and can be good for other user agents such as wireless devices.

(6) in web Design, XHTML can help you remove the abuse of the presentation layer code, helping you to develop the habit of marking validation to test the work of the page.

DHTML:

DHTML is just a concept of making a Web page, and no organization or institution has ever launched a so-called DHTML standard or technical specification. DHTML is not a technology, standard, or specification, and DHTML is simply the design concept of a Web page that will be able to transform the effects of page elements in real time after downloading the existing Web technologies, language standards, and applications.

DHTML roughly includes the following Web page technologies, standards, or specifications:

HTML 4.0 Nothing to say, the basic language standard for Web pages.

CSSL, look out! Not CSS, is Cssl, it is clent-side scripting language abbreviation, translated "Client script language", mainly JavaScript (JS), VBScript (VBS), JScript. Netscape mainly supports Js,ie mainly support js,vbs and JScript.

The abbreviation of DOM Document Object model, which is one of the web technology standards that has been promoted by the consortium recently, abstracts the contents of Web pages into objects, each with its own attributes (properties), methods (method), and events ( Events), these can be controlled by the Cssl mentioned above. Both the IE and NS object models are based on the published Dom of the consortium, plus their own extended object (extended objects).

CSS This is the cascading style Sheets (cascading style form) abbreviation, but also the theme of the site 52css.com, it is the HTML Auxiliary design specification, to make up for the HTML in the layout of the limitations caused by the deficiencies, it is part of the DOM. In theory, changing CSS properties dynamically through CSSL can make any page visual effect you want.

So, simply put, to achieve DHTML, it is based on HTML, using DOM to use the page elements to object, using Cssl to control the CSS properties of these objects to achieve the dynamic visual effects of the Web page.

SHTML:

Ask the difference between shtml and HTML, if one sentence to explain is: shtml is not HTML but a server api,shtml is dynamically produced by the server HTML.

While both are hypertext formats, shtml is a file for SSI technology. That is, the server Side Include--ssi contains instructions. If the Web server has SSI capabilities, most (especially unix-based platform-based Web servers such as Netscape Enterprise Server support SSI commands). Special hospitality to shtml files. First sweep shtml file to see no special SSI instructions now. An SSI directive is interpreted according to the Web server settings rule. When explained, drop the client with the general HTML.

sHTML uses the HTML file name extension of SSI (server Side include), SSI (server Side include), commonly referred to as "servers-side embedding" or "server-side inclusion", is an ASP-like server-based Web-making technology.

How SSI works:

Before you send content to the browser, you can use the server side include (SSI) directive to include text, graphics, or application information in a Web page. For example, you can use SSI to include a time/date stamp, a copyright notice, or a form for a customer to fill out and return. For text or graphics that repeats in multiple files, using the include file is an easy way to do so. Save the content in a containing file without having to enter the content into all the files. You can invoke the include file with a very simple statement that instructs the WEB server to insert content into the appropriate Web page. Also, when you use the Include file, all changes to the content can be done in just one place.

Because files that contain SSI directives require special processing, the SSI file extension must be given to all SSI files. The default extension is. stm,. shtm and. shtml

The Web server processes the SSI directives while processing the Web page. When the Web server encounters an SSI directive, inserts the contents of the containing file directly into the HTML Web page. If an SSI directive is included in the include file, insert the file at the same time. In addition to the basic directives used to include files, you can use SSI directives to insert information about a file, such as the size of a file, or to run an application or shell command.

Site maintenance often encountered a problem is that the structure of the site has been fixed, but in order to update a little content and have to redo a large number of pages. SSI provides a simple, effective way to solve this problem, it will be the basic structure of a Web site in a few simple HTML files (templates), we have to do is to upload text to the server, so that the program to follow the template to automatically generate Web pages, so that the management of large Web sites becomes easier.

Therefore, the use of the shtml format of the page is similar to the ASP, but because it is the API is faster, more efficient, faster than the ASP, slower than the HTML, but because you can use the server side contains, so make the page update easy (especially batch update banner, copyright, etc.), imagine it, You have a section of HTML, to insert some special server script in the middle, such as inserting other HTML paragraphs, you choose ASP to complete the task, but if the task is heavier, need more time, such as 5s, this time you do not use ASP and SHTML, perhaps processing time only with 4s.