The blink element is a non-standard presentational HTML element An HTML element is an individual component of an HTML document. HTML documents are composed of a tree of HTML elements and other nodes, such as text nodes. Each element can have attributes specified. Elements can also have content, including other elements and text. HTML elements represent semantics, or meaning. For example, the title element that indicates to a user agent A user agent is a client application implementing a network protocol used in communications within a client–server distributed computing system. The term most notably refers to applications that access the World Wide Web, but other systems, such as the Session Initiation Protocol , use the term user agent to refer to both end points of a (generally a web browser A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content. Hyperlinks present in resources enable users to easily navigate their browsers to) that the page author intends the content of the element to blink (that is, alternate between being visible and invisible). The element was introduced in Netscape Navigator Netscape Navigator and Netscape are the names for the proprietary web browser popular in the 1990s, the flagship product of the Netscape Communications Corporation and the dominant web browser in terms of usage share, although by 2002 its usage had almost disappeared. This was partly due to the increased usage of Microsoft's Internet Explorer web and has some support in other web browsers, but support for the feature is absent from Internet Explorer Windows Internet Explorer , is a series of graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems starting in 1995. It has been the most widely used web browser since 1999, attaining a peak of about 95% usage share during 2002 and 2003 with IE5 and IE6.
Despite the element being initially popular amongst personal homepages Personal web pages are World Wide Web pages created by an individual to contain content of a personal nature rather than on behalf of an employer or institution. Personal web pages are often used solely for informative or entertainment purposes, it has since fallen out of favor due to its overuse and the difficulty it presents in reading[1]. The tag achieved notoriety for being extremely user-unfriendly.
Lou Montulli is credited as the inventor An invention is a new composition, device, or process. An invention may be derived from a pre-existing model or idea, or it could be independently conceived in which case it may be a radical breakthrough. In addition, there is cultural invention, which is an innovative set of useful social behaviors adopted by people and passed on to others of the blink tag, although he only suggested the idea, without writing any actual code.[2]
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Usage
The blink element is non-standard, and as such there is no authoritative specification of its syntax. While Bert Bos Gijsbert Bos (born 10 November 1963, The Hague) is a computer scientist. He studied mathematics at the University of Groningen, and wrote his PhD thesis on Rapid user interface development with the script language Gist of the World Wide Web Consortium The World Wide Web Consortium is the main international standards organization for the World Wide Web (abbreviated WWW or W3) has produced a Document Type Definition Document Type Definition is a set of markup declarations that define a document type for SGML-family markup languages (SGML, XML, HTML). A DTD is a kind of XML schema that includes syntax for the blink element (defining it as a phrase element on a par with elements for emphasis A means of emphasis that does not have much effect on “blackness” is the use of italics, where the text is written in a script style, or the use of oblique, where the vertical orientation of all letters is slanted to the left or right. With one or the other of these techniques , words can be highlighted without making them stand out much from and citations Broadly, a citation is a reference to a published or unpublished source .[citation needed] More precisely, a citation is an abbreviated alphanumeric expression (e.g. [Newell84]) embedded in the body of an intellectual work that denotes an entry in the bibliographic references section of the work for the purpose of acknowledging the relevance of), the comments in the DTD explain that it is intended as a joke.[3]
Syntax of the blink element type is identical to such standard HTML HTML, which stands for HyperText Markup Language, is the predominant markup language for web pages. It is written in the form of HTML elements consisting of "tags" surrounded by angle brackets within the web page content inline elements as span. For example: <blink>This text could blink</blink>.
The rate of blinking is browser-specific. In Mozilla Firefox Mozilla Firefox is a free and open source web browser descended from the Mozilla Application Suite and managed by Mozilla Corporation. A Net Applications statistic put Firefox at 24.59% of the recorded usage share of web browsers as of April 2010[update], making it the second most popular browser in terms of current use worldwide after Microsoft's the text alternates between being visible for three quarters of a second and being invisible for one quarter of a second.[4]
The blink element type was first invented for Netscape Navigator Netscape Navigator and Netscape are the names for the proprietary web browser popular in the 1990s, the flagship product of the Netscape Communications Corporation and the dominant web browser in terms of usage share, although by 2002 its usage had almost disappeared. This was partly due to the increased usage of Microsoft's Internet Explorer web and is still supported in its descendants, such as Mozilla Firefox Mozilla Firefox is a free and open source web browser descended from the Mozilla Application Suite and managed by Mozilla Corporation. A Net Applications statistic put Firefox at 24.59% of the recorded usage share of web browsers as of April 2010[update], making it the second most popular browser in terms of current use worldwide after Microsoft's (except for the Netscape 6 Netscape 6 was the name of Netscape Communications Corporation's proprietary cross-platform internet suite from versions 6.0-6.2.3. It superseded Netscape Communicator 4.8 and was replaced by the simply-named Netscape. Netscape 6, and later Netscape 7, were based on the Mozilla Application Suite, an open-source software package which at that time and early Mozilla suite The Mozilla Application Suite is a cross-platform integrated Internet suite. Its development was initiated by Netscape Communications Corporation, before their acquisition by AOL. It is based on the source code of Netscape Communicator. The development was spearheaded by the Mozilla Organization from 1998 to 2003, and by the Mozilla Foundation browsers). It is also supported by the Opera Internet Browser Opera is a web browser and Internet suite developed by Opera Software. The browser handles common Internet-related tasks such as displaying web sites, sending and receiving e-mail messages, managing contacts, chatting on IRC, downloading files via BitTorrent, and reading Web feeds. Opera is offered free of charge for personal computers and mobile. Microsoft Microsoft Corporation is a public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions. Established on April 4, 1975 to develop and sell BASIC interpreters for the Altair 8's Internet Explorer Windows Internet Explorer , is a series of graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems starting in 1995. It has been the most widely used web browser since 1999, attaining a peak of about 95% usage share during 2002 and 2003 with IE5 and IE6 and Apple Apple Inc. is an American multinational corporation that designs and markets consumer electronics, computer software, and personal computers. The company's best-known hardware products include the Macintosh computers, the iPod, the iPhone and the iPad. Apple software includes the Mac OS X operating system; the iTunes media browser; the iLife suite's Safari Safari is a graphical web browser developed by Apple and included as part of the Mac OS X operating system. First released as a public beta on January 7, 2003 on the company's Mac OS X operating system, it became Apple's default browser beginning with Mac OS X v10.3 "Panther." Safari is also the native browser for the iPhone OS. A/WebKit WebKit is a layout engine designed to allow web browsers to render web pages. The WebKit engine provides a set of classes to display web content in windows, and implements browser features such as following links when clicked by the user, managing a back-forward list, and managing a history of pages recently visited do not support it, even in its CSS incarnation.
Implementation
The blink value of the CSS Cascading Style Sheets is a style sheet language used to describe the presentation semantics (that is, the look and formatting) of a document written in a markup language. Its most common application is to style web pages written in HTML and XHTML, but the language can also be applied to any kind of XML document, including SVG and XUL text-decoration property allows authors to suggest that text should blink without using proprietary tags, but the CSS 2.1 Specification states that "conforming user agents may simply not blink the text" in order to comply with the User Agent Accessibility Guidelines.[5]
Example:
<style>
.advertisement {
text-decoration: blink;
}
</style>
Usability and accessibility
The blink element has been consistently criticised by usability In design, usability is the study of the ease with which people can employ a particular tool or other human-made object in order to achieve a particular goal. This can include endeavors as varied as consumer electronics, communication, and knowledge transfer objects and mechanical objects such as a door handles or a hammer and accessibility Accessibility is a general term used to describe the degree to which a product, device, service, or environment is accessible by as many people as possible. Accessibility can be viewed as the "ability to access" and possible benefit of some system or entity. Accessibility is often used to focus on people with disabilities and their right experts. In 1996 Jakob Nielsen Jakob Nielsen is a leading web usability consultant. He holds a Ph.D. in human-computer interaction from the Technical University of Denmark in Copenhagen. He is considered a foremost expert on usability described the element as "simply evil" in his Alertbox column Top Ten Mistakes in Web Design.[6]
The World Wide Web Consortium's Web Content Accessibility Guidelines Web Content Accessibility Guidelines are part of a series of Web accessibility guidelines published by the W3C's Web Accessibility Initiative. They consist of a set of guidelines on making content accessible, primarily for disabled users, but also for all user agents, including highly limited devices, such as mobile phones. The current version is 2 1.0 state that content authors should avoid causing the screen to flicker or blink, noting that such effects can cause problems for people with cognitive disabilities or photosensitive epilepsy Photosensitive epilepsy is a form of epilepsy in which seizures are triggered by visual stimuli that form patterns in time or space, such as flashing lights, bold, regular patterns, or regular moving patterns.[7]
The German A region named Germania, inhabited by several Germanic peoples, has been known and documented before AD 100. Beginning in the 10th century, German territories formed a central part of the Holy Roman Empire, which lasted until 1806. During the 16th century, northern Germany became the centre of the Protestant Reformation. As a modern nation-state, Federal Government's Barrierefreie Informationstechnik-Verordnung (Barrier-free Information Technology Ordinance) also states that flickering or blinking content should be avoided.[8]
The United States ^ b. English is the de facto language of American government and the sole language spoken at home by 80% of Americans age five and older. Spanish is the second most commonly spoken language Federal Government's Section 508 states that pages should avoid causing the screen to flicker with a frequency between 2 Hz The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of sine wave, particularly those used in radio and audio applications and 55 Hz, a range which covers rapidly blinking text.[9]
To comply with the User Agent Accessibility Guidelines a user agent must either "allow configuration to render animated or blinking text content as motionless, unblinking text" or never blink text.[10] Mozilla Firefox Mozilla Firefox is a free and open source web browser descended from the Mozilla Application Suite and managed by Mozilla Corporation. A Net Applications statistic put Firefox at 24.59% of the recorded usage share of web browsers as of April 2010[update], making it the second most popular browser in terms of current use worldwide after Microsoft's satisfies this requirement by providing a hidden configuration option to disable blinking.[4]
See also
- Marquee element The marquee tag is a non-standard HTML element which causes text to scroll up, down, left or right automatically. The tag was first introduced in early versions of Microsoft's Internet Explorer, and was compared to Netscape's blink element, as a proprietary non-standard extension to the HTML standard with usability problems. It is deprecated by
- Comparison of layout engines (Non-standard HTML)
References
- ^ "Blink Element Usage Statistics". BuiltWith.com. http://trends.builtwith.com/docinfo/Blink-Element. Retrieved 2010-01-20.
- ^ "The Origins of the <blink> Tag". www.montulli.org. http://www.montulli.org/theoriginofthe%3Cblink%3Etag. Retrieved 2009-10-23.
- ^ Bos, Bert. "HTML40, but with BLINK added". World Wide Web Consortium. http://www.w3.org/Style/HTML40-plus-blink.dtd. Retrieved 2006-12-12.
- ^ a b "VPAT for Firefox 3.0 and 3.5". Mozilla. http://www.mozilla.com/en-US/firefox/vpat.html. Retrieved 2009-10-23.
- ^ "Cascading Style Sheets, level 1". Cascading Style Sheets Working Group, World Wide Web Consortium. http://www.w3.org/TR/CSS21/text.html. Retrieved 2009-10-23.
- ^ "Original Top Ten Mistakes in Web Design (Alertbox)". Useit.com. http://www.useit.com/alertbox/9605a.html. Retrieved 2009-10-23.
- ^ "Web Content Accessibility Guidelines 1.0". W3.org. http://www.w3.org/TR/WCAG10/. Retrieved 2009-10-23.
- ^ "BITV — Einzelnorm". Bundesrecht.juris.de. http://bundesrecht.juris.de/bitv/anlage_8.html. Retrieved 2009-10-23.
- ^ Government Services Administration. "Section 508: Section 508 Standards". Section508.gov. http://www.section508.gov/index.cfm?FuseAction=Content&ID=12. Retrieved 2009-10-23.
- ^ "2. The user agent accessibility guidelines". W3.org. 2002-12-17. http://www.w3.org/TR/UAAG/guidelines.html. Retrieved 2009-10-23.
External links
Categories: HTML
