HTML editor

From Wikipedia, the free encyclopedia

An HTML editor is a software application for creating web pages. Although the HTML markup of a web page can be written with any text editor, specialised HTML editors can offer convenience and added functionality. For example, many HTML editors work not only with HTML, but also with related technologies such as CSS, XML and JavaScript or ECMAScript. In some cases they also manage communication with remote web servers via FTP and WebDAV, and version management systems such as CVS or Subversion.

Contents 1 Types 1.1 Text editors 1.2 WYSIWYG HTML editors 1.3 WYSIWYM editors 2 Valid HTML code 3 Difficulties in achieving WYSIWYG 4 Comparison of HTML editors 5 General information 5.1 Operating system support 5.2 Editor features 5.3 Web technology support 5.4 Image format support 6 See also 7 References 8 External links

[edit] Types

There are two flavors of HTML editors: text and WYSIWYG (What You See Is What You Get) -editors.

[edit] Text editors

Text (source) editors intended for use with HTML usually provide syntax highlighting. Templates, toolbars and keyboard shortcuts may quickly insert common HTML elements and structures. Wizards, tooltip prompts and auto-completion may help with common tasks.

Text HTML editors commonly include either built-in functions or integration with external tools for such tasks as source and version control, link-checking, code checking and validation, code cleanup and formatting, spell-checking, uploading by FTP or WebDAV, and structuring as a project.

Text editors require user understanding of HTML and any other web technologies the designer wishes to use like CSS, JavaScript and server-side scripting languages.

Some WYSIWYG editors allow alternate source text editing modes. Adobe GoLive provides an outline editor to expand and collapse HTML objects and properties, as an alternative to using colors for organizing and editing of source text, and to view visual properties attached to the expanded objects.

[edit] WYSIWYG HTML editors

So-called WYSIWYG HTML editors provide an editing interface which resembles how the page will be displayed in a web browser. Most WYSIWYG editors also have a mode to edit HTML directly as described above. Because using a WYSIWYG editor does not require any HTML knowledge, they are easier for an average computer user to get started with.

The WYSIWYG view is achieved by embedding a layout engine based upon that used in a web browser. The layout engine will have been considerably enhanced by the editor's developers to allow for typing, pasting, deleting and moving the content. The goal is that, at all times during editing, the rendered result should represent what will be seen later in a typical web browser.

WYSIWYG editors are sometimes criticized because:

• They generally do not generate the most efficient HTML and CSS code. Layout may be based on HTML tables rather than CSS. This makes documents inefficient to download, adds complexity and obfuscates the documents' structures, resulting in code that is hard to maintain. Although third-party optimizers are supposed to solve the problems, many of them simply remove extra spaces, rather than looking into the code to remove unneeded structures like compilers do. Furthermore, unless the optimizer operates as a plug-in for the editor, it cannot take the web author's behaviour into account when content is created, resulting in mis-optimized code.
• Users may be disappointed that the same page is rendered differently in different browsers and on various screen sizes and resolutions. There are many factors outside of the page designer's control that can affect this—the CSS specification and modern browsers even allow users to override a page author's settings.
• Documents edited visually without regard to semantic structure can be incomprehensible to search engines, audio and text-only browsers.

[edit] WYSIWYM editors

What You See Is What You Mean (WYSIWYM) is an alternative paradigm to the WYSIWYG editors above. Instead of focusing on the format or presentation of the document, it preserves the intended meaning of each element. For example, page headers, sections, paragraphs, etc. are labeled as such in the editing program, and displayed appropriately in the browser.

[edit] Valid HTML code

HTML is a structured markup language. There are certain rules on how HTML must be written if it is to conform to W3C standards for the World Wide Web. Following these rules means that web sites are accessible on all types and makes of computer, to able-bodied and disabled people, and also on wireless devices like mobile phones and PDAs, with their limited bandwidths and screen sizes.

Unfortunately most HTML documents on the web are not valid according to W3C standards. According to one study only about 1 out of 141 is valid. Even those syntactically correct documents may be inefficient due to an unnecessary use of repetition, or based upon rules that have been deprecated for some years. Current W3C recommendations on the use of CSS with HTML were first formalised by W3C in 1996[1] and have been revised and refined since then. See CSS, XHTML, W3C's current CSS recommendation and W3C's current HTML recommendation.

These guidelines emphasise the separation of content (HTML or XHTML) from style (CSS). This has the benefit of delivering the style information once for a whole site, not repeated in each page, let alone in each HTML element. WYSIWYG editor designers have been struggling ever since with how best to present these concepts to their users without confusing them by exposing the underlying reality. Modern WYSIWYG editors all succeed in this to some extent, but many would say that none of them yet succeed totally.

People who use text editors can generally fix such problems immediately, once they become aware of them. People find it frustrating when such errors come from WYSIWYG editors.

However a web page was created or edited, WYSIWYG or by hand, in order to be successful among the greatest possible number of readers and viewers, as well as to maintain the 'worldwide' value of the Web itself it can be argued that, first and foremost, it should consist of valid markup and code. Some would argue that it should not be delivered by a designer to his or her customer, and not be considered ready for the World Wide Web, until its HTML and CSS syntax has been successfully validated using either the free W3C validator services (W3C HTML Validator and W3C CSS Validator) or some other trustworthy alternatives.

Others would argue[2] that publishing useful information, as soon as possible, should be first and foremost.

Whatever software tools are used to design, create and maintain web pages, there is little doubt that the quality of the underlying HTML is dependent on the skill of the person who works on the page. Some knowledge of HTML, CSS and other scripting languages as well as a familiarity with the current W3C recommendations in these areas will help any designer produce better web pages, with a WYSIWYG HTML editor and without[3].

[edit] Difficulties in achieving WYSIWYG

A given HTML document will look different to different people for several reasons: (See CSS Zen Garden for an extreme example.)

Different browsers and applications will render the same markup differently.

The same page may display slightly differently in Internet Explorer and Firefox on a high-resolution screen, but it will look very different in the perfectly valid text-only Lynx browser. It needs to be rendered differently again on a PDA, an internet-enabled television and on a mobile phone. Usability in a speech or braille browser, or via a screen-reader working with a conventional browser, will place demands on entirely different aspects of the underlying HTML. Printing the page, via different browsers and different printers onto various paper sizes, around the world, places other demands. With the correct use of modern HTML and CSS there is no longer any need to provide 'Printable page' links and then have to maintain two versions of the whole site. Nor is there any excuse for pages not fitting the user's preferred paper size and orientation, or wasting ink printing solid background colours unnecessarily, or wasting paper reproducing navigation panels that will be entirely useless once printed out[4].

Browsers and computer graphics systems have a range of user settings.

Resolution, font size, colour, contrast etc can all be adjusted at the user's discretion, and many modern browsers allow even more user control over page appearance[5]. All an author can do is suggest an appearance.

Web browsers, like all computer software, have bugs

They may not conform to current standards. It is hopeless to try to design Web pages around all of the common browsers current bugs: each time a new version of each browser comes out, a significant proportion of the World Wide Web would need re-coding to suit the new bugs and the new fixes! It is generally considered much wiser to design to standards, staying away from 'bleeding edge' features until they settle down, and then wait for the browser developers to catch up to your pages, rather than the other way round[6]. In this regard, no one can argue that CSS/XHTML is still 'cutting edge' as there is now widespread support available in common browsers for all the major features[7], even if many WYSIWYG and other editors have not yet entirely caught up[8].

What you see may be what most visitors get, but it is not guaranteed to be what everyone gets.

[edit] Comparison of HTML editors

The following tables compare general and technical information for a number of (purportedly) WYSIWYG HTML editors. Please see the individual products' articles for further information, and Comparison of text editors for information on text editors, many of which have features to assist with writing HTML. This article is not all-inclusive or necessarily up-to-date.

[edit] General information

Basic general information about the browsers: creator/company, license/price etc.

Editor	Version	Creator	Cost (USD)	Software license
Amaya	9.52	W3C, INRIA	Free	W3C
Aptana	0.31 Beta	?	Free	EPL
Composer	1.7	Mozilla Foundation	Free	MPL/GPL/LGPL
Dreamweaver	8	Adobe Systems (formerly Macromedia)	US $399	Closed source
FrontPage	2003	Microsoft	US $199	Closed source
HomeSite	5.5	Adobe Systems (formerly Macromedia)	USD $99 EUR €123	Adobe Acrobat License

[edit] Operating system support

Editor	Windows	Mac OS X	Mac OS 9	Linux	BSD	Unix
Amaya	Yes	Yes	No	Yes	source only	source only
Aptana	Yes	Yes	No	Yes	?	?
Composer	Yes	Yes	Yes?	Yes	No?	No?
Dreamweaver	Yes	Yes	Dropped	No	No	No
Microsoft FrontPage	Yes	No	No[1]	No	No	No
Nvu [2]	Yes	Yes	No?	Yes	Yes	?

[edit] Editor features

Editor	FTP Upload	Server-side scripting	Shared editing	Spell checking	Templates
Amaya	No	No	No	Yes	No
Aptana	No	No	No	No	No
Composer	Yes?	No	No	Yes	No
Dreamweaver	Yes	Yes	Yes	Yes	Yes
Microsoft FrontPage	Yes	Yes	Yes	Yes	Yes
Nvu	Yes	?	?	Yes	Yes

[edit] Web technology support

Editor	CSS2	Frames	Java	JavaScript	XSLT	XHTML †	MathML	XForms	RSS	Atom	XPath
Amaya	Partial	No	No	No	No	Yes	Yes	No	No	No	?
Aptana	Yes	?	?	Yes	?	Yes	?	?	?	?	?
Composer	No	Yes	No	Yes	No	No	No	No	No	No
Dreamweaver	Yes	Yes	No	Yes	Yes	Yes	Partial	?	Yes	?	Yes
FrontPage	Partial	Yes	Yes	Yes	Yes	Yes	Yes	No	No	No	No
Nvu	Yes	No	No	Yes	?	Yes	?	?	?	?	?

[edit] Image format support

Editor	JPEG	GIF	PNG	MNG	TIFF	SVG	PDF
Amaya	Yes	Yes	Yes	?	Yes	Yes	No
Aptana	Yes	Yes	Yes	?	Yes	Depends	Depends
Composer	Yes	Yes	Yes	No	No	No	No
Dreamweaver	Yes	Yes	Yes	No	No	No	?
FrontPage[3]	Yes	Yes	Yes	Depends	Yes?	Depends	Depends
Nvu	Yes	Yes	Yes	?	?	?	?

[edit] See also

• List of HTML editors
• Web template system
• Website builder
• Validator

[edit] References

1. ^ A version for Mac OS was released around 1998, but has since been discontinued.
2. ^ Nvu can be built successfully on any platform with the Netscape Portable Runtime.
3. ^ Actual amount of supported formats depend on installed converter. FrontPage uses Microsoft Office converters.

[edit] External links

• Starting with HTML + CSS - W3C tutorial
• Online-HTML-Editor.org
• KTML - online HTML editor