XHTML, an acronym for eXtensible Hypertext Markup Language listed on ABBREVIATIONFINDER, is the markup language intended to replace HTML as a standard for Web Pages. In its version 1.0, XHTML is only the XML version of HTML, so it has basically the same functionalities, but meets the more stringent specifications of XML. Its objective is to advance the World Wide Web Consortium (W3C) project to achieve a Semantic Web, where the information and the way of presenting it are clearly separated. Version 1.1 is similar, but starts from the specification in modules. In successive versions the W3C plans to break with the classic tags brought from HTML.
History of XHTML
In parallel to its activity with HTML, W3C has developed the XHTML standard. The first version of XHTML is called XHTML 1.0 and was released on January 26, 2000 (and was later revised on August 1, 2002).
XHTML 1.1 version has already been released in draft form. The draft of XHTML 2.0 has also been published, which will represent a very important change with respect to the previous versions of XHTML.
XHTML is a powerful language for creating Web content, but its design does not take into account issues pertaining to small devices, including the cost of implementation (on power, memory, etc.) of the full feature set. Consumer devices with limited resources generally cannot afford to implement the full feature set of HTML. The requirement of a full-fledged computer and the right to access the World Wide Web excludes a large part of the population from consumer access to information devices and online services.
XHTML for small information gadgets
HTML version 4 is a powerful language for creating Web content, but its design does not take into account the relevant aspects for small devices, including the cost of implementation (battery, memory, etc.) of the full set of features.
Resource-constrained consumer devices generally cannot cope with implementing the full feature set of HTML 4. Requiring a fully capable computer to access the World Wide Web excludes a large portion of the population from accessing their business devices to the web. online information and services. Since there are many ways to subdivide HTML, there are many identical subsets defined by organizations and companies. Without a common base of feature sets, developing applications for a wide range of Web clients is difficult.
The motivation for XHTML Basic is to provide an XHTML document type that can be shared across communities (desktop, TV, and Mobile Phones), and is rich enough to be used for simple content creation. New community-created document types can be created using the XHTML Basic extension as long as the XHTML Basic documents are in the valid document group of the new document type. Therefore, a Basic XHTML document can be presented to the maximum number of Web clients.
The document type definition for Basic XHTML is implemented based on the XHTML Modules defined in XHTML Modularization [HTMLMOD.
Background and Requirements
Information devices, (specialized in accessing the Web), are intended for particular uses. They support the features they need for the functions they are intended to perform. The following are examples of different information devices:
- Mobile phones
- Vending machines
- Car Navigation Systems
- Mobile Gaming Machines
- Digital Book Readers
- Smart Watches
Subsets and variations of XHTML
Existing for these devices include Compact HTML CHTML, the Wireless WML Markup Language, and the GUIDELINES ” HTML 4.0 Guidelines for Mobile Access.” Common characteristics that we find in these document types include:
- Basic Text (including headings, paragraphs, and lists)
- Hyperlinks and links to related documents
- Basic Forms
- Basic Tables
- Meta information
This group of HTML features has been the starting point for the design of XHTML Basic. Since many content developers are familiar with these features of HTML, they will understand the usefulness of a host language that can be combined with markup modules from other languages according to the methods described in “Modularizing XHTML” XHTMLMOD.
For example, XHTML Basic can be extended with an event module that is more generic than the traditional HTML 4 event system or it can be extended with additional modules from XHTML Modularization such as the Scripting Module. It is not the intention of XHTML Basic to limit the functionality of future languages. But if we assume that the HTML 4 features (frames, advanced tables, a fixed set of event-handling attributes, etc.) were developed for a desktop-type client, they have proven to be inappropriate for most different devices.. XHTML Basic will be extended and rebuilt.
Extending XHTML from a set of basic and common features, rather than nearly identical subsets or the overly long set of HTML 4 features, will be good for web interoperability as well as scalability. Compared to the rich functionality of HTML 4, XHTML Basic may seem like a step backwards, but in fact, it is two steps forward for clients who do not need what is in HTML 4 and for content developers who have a subset of XHTML in place.
The style element is not supported. External style sheets are recommended. The link element can be used to include external style sheets. The div and span elements and the class attribute are supported to bind the style information to the structure. The separation between structure and presentation allows user agents to download the style sheets if they support them; user agents that do not support style sheets can ignore external style sheets.
The media attribute can be used to select the appropriate style sheets. See the section on “Media Types” in the HTML 4.01 (HTML4) specification.
Script and Events
The script and noscript elements are not supported. Small devices typically have limited memory and CPU capacity. Running Script Programs is not supported. The contents should be readable even if the scripts are not executed. Event handler attributes used to invoke script programs are not supported. Events are device dependent. A call to the production of an event is unlikely to occur on television. A generic Event handling mechanism might be more appropriate than forcing the event names in the document type definition.
Many simple web clients cannot display fonts other than monospace. Bi-directional texts, bold fonts, and other text extension elements are not supported. It is recommended that the style sheets be used to create a presentation according to the device.
XHTML Basic Forms (XHTMLMOD)
They are supported since only devices with local file systems can take advantage of file and image type input in forms, these are not included in basic forms. Also, content developers should keep in mind that users may not be able to insert characters from some devices (eg from a mobile phone).
Basic XHTML Tables (XHTMLMOD)
They are supported, but the tables can be difficult to display on small devices. It is recommended that content developers follow the Web Content Accessibility Guidelines 1.0 to create accessible tables (WCAG10], Guideline 5). Note that in the Basic Table Module, table nesting is prohibited. 1.3.6. Marcos Las Marcos are not supported. They depend on a screen interface and are not applicable to many small devices such as phones, pagers, and watches. Encab 1 The Basic XHTML Document Type. The Basic XHTML document type is defined as a group of XHTML modules. All XHTML modules are defined in the XHTMLMOD “Modularization of XHTML” specification.
XHTML Basic is made up of the following XHTML modules:
- Structure Module * body, head, html, title
- Text Module * abbr, acronym, address, blockquote, br, cite, code, dfn, div, em, h1, h2, h3, h4, h5, h6, kbd, p, pre, q, samp, span, strong, var
- Hypertext Module * to List Module * dl, dt, dd, ol, ul, li
- Basic Form Module form, input, label, select, option, textarea
- Basic Tables Module caption, table, td, th, tr
- Image Module img
Objects module object, param
- Meta Meta information module
- Link module link
- Base module bas.
How to Use Basic XHTML
Although Basic XHTML can be used as it is – a simple XHTML language with text, links, and images – its simple design is intended to be used as a Host Language. A host language can contain a mixture of vocabularies listed in the same document type.
It is normal for XHTML to be a host language, as it is what many web developers are used to. When markups from other languages are added to XHTML Basic, the resulting document type will be an extension of XHTML Basic. Content developers can develop for Basic XHTML or take advantage of extensions. The goal of XHTML Basic is to serve as a common language supported by various types of user agents.