Outline
What You’re In For
Why XHTML & CSS?
XHTML
CSS
Making the Transition
The Future
Good Web and Database design practices
What You’re In For
This presentation focuses mainly on the
front-end i.e. the web-pages of an enterprise database application
XHTML and CSS are the latest trends in web design and play a major role in enhancing the usability of the application
Why XHTML & CSS?Garbage code is…uh…garbage!Information encoded in XHTML can be more easily migrated as technology changesXHTML is a good step forward to learning XMLYou can easily make global changes to how your documents display There are user benefits to separating information from presentation
What is XHTML
XHTML stands for eXtensible HyperText Markup Language
XHTML is aimed to replace HTML
XHTML is a stricter and cleaner version of HTML
XHTML is HTML defined as a XML application
XHTML is a W3C Recommendation
XHTML …why?Many pages on the WWW contain bad HTML
XML is a markup language where everything has to be marked up correctly, which results in "well-formed"
documents. Hand held devices like PDA’s and mobile phones do not have resources and power to interpret bad HTML code
A mark-up language for now and for the future. Future browser versions may support only XHTML…so be prepared!!!
XHTML Benefits
A painless transition to more advanced technology (XML)
Clean, more logical markup
Increased interoperability
Greater accessibility
XHTML-key ingredient in mobile browsing
XHTML reduces the difference between wireless and web content
XHTML Basic and Cascading Style Sheets separate content from presentation enabling content tailoring to different devices
Benefits:Consumers –more services, better userinterface, easier-to-use
Carriers – more control over content,consistent look & feel, service loyalty
Content providers – presentation, functionality,consistency, familiar format
Manufacturers – Easier software
maintenance, better performance, lower cost
How can I convert to XHTML??Very few simple rules…that’s it!
All tags must be in lowercase:<title></title>
All tags must end:<p></p>
Even empty tags:<br></br> = <br />
All tags must properly nest:<p>This is an <a name=“here”>anchor</a>.</p>
All attribute values must be quoted:<div align=“center”></div>
XHTML: More RulesAttribute minimization is forbidden:
<input type=“radio” name=“stuff” CHECKED> becomes…<input type=“radio” name=“stuff” checked=“checked” />
You must use a document type declaration:Transitional: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
Strict: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
And add a namespace declaration to <html>:<html xmlns=“http://www.w3.org/1999/xhtml” xml:lang=“en” lang=“en”>
Evolution of XHTML standards
HTML 4.0 TransitionalXHTML BasicXHTML TransitionalXHTML Strict
There are online validation tools available which check conformance to standards-
Kick It Up a Notch: Enhance your web page with Cascading Style Sheets
CSS is a standard layout language for the Web
Though precise and powerful, CSS is easy to author by hand.
Replace HTML table-based layouts, frames, and other presentational hacks.
Separate style from content
Benefits of CSSConserve bandwidth (less markup for visitors to download) Reduce design/development time Reduce updating and maintenance time Increased accessibility (fewer, or no, HTML tables; no invalid junk markup) Adhere to W3C recommendations, improving interoperability and ensuring greater longevity Better, more professional appearance (line–height, borders, padding, margins) Increased readability (line–height, borders, padding, margins) More easily transition in future to more powerful standards such as XML (because page content no longer contains junk markup)
CSS: Rule Structure
h1 { color: purple; }
h1 { font-family: Optima, Arial, sans-serif; }
propertyproperty valuevalue
begins and ends the declarationbegins and ends the declaration
property/valueproperty/valueseparatorseparator
ends everyends everyproperty/property/value pairvalue pair
declarationdeclarationselectorselector
CSS Rule Example
body {
background: #FFFFFF;
color: black;
margin-left: 5%;
margin-right: 5%;
font-family: Tahoma, Optima, Arial, sans-serif;
}
Where do you put styles?In-line - add to HTML tag<H1 style="color: maroon">
Embedded style sheets<style> </style>
External style sheets<link href="style.css">
In-line<H1 style="color: maroon">
Similar to adding attributes to html tags
Disadvantagesdecreased accessibilityincreased file sizeharder to update
Embedded style sheets<style> <!--h1 {font-family: arial, sans-serif;} --> </style>
Put rules between style tags Put in head section Add html comment tags Use when single document has unique style
External style sheets<link rel="stylesheet" type="text/css" href="style.css">
Save rules in external file
Advantagesease of maintenance
use less disk space
increase accessibility
Class selector & attributeTo create rules that can be applied to a
variety of html tags<style>.bar {color: maroon; font-size: smaller; background-color: yellow;}</style>
…<p class="bar">text</p>…
<p><a href="url.htm" class="bar">link</a> </p>
CSS: Diagram of Precedence
External
StyleSheet
[call to external stylesheet]
[styles embedded inside the document]
XHTML File
1)
2)
Generalized order of precedence, all other things being equal
Making the Transition: TidyHTML Tidy is free software that can read your HTML and output a much better file by:
Automatically fixing some errorsChanging uppercase tags to lowercaseIndenting your code to make to make it more readableQuote all attribute valuesAnd other things, depends on configuration file
An error report may also be generated that can identify remaining problems
Making the Transition:Migrating an Existing Site
All at once:Copy entire site to another location
Run Tidy; check and re-run as needed
Clean up remaining problems
Transfer back
Gradual:Do all new things in XHTML/CSS
Migrate old files as you update them for other reasons
The Future
Will XML replace HTML?
It already has! That’s why you’re here!
XML will typically not be delivered to web clients; that is what XHTML will be for
So, is this the last markup you have to learn?
No way! Use this as a stepping-stone to XML, for which you will have many additional uses
Remember — Never stop learning!
Adding hit counters to your web-site for free
Just register at www.google.com/analytics
Type in the url of your web-site
You will get a javascript code snippet
Just add the code to your index page
You get daily reports about user activity
on your site
Good web-design practices:Comment your code!Use XHTML rules and CSSUse AJAX to enhance user interaction and increase speedArchive code before making any changes to the current web-siteRe-use code: eg: Database connection code, reusable javascript subroutinesUse lower-case more than upper-case, it looks more attractive and subtle
Good database design practices
Comment your code!Don’t store big binary files in the databaseCorrectly identify which fields require dataIf a column storing the same data appears
or is referenced in more than one table (e.g. a foreign key), it should have the same data type throughout the database.
Continued…When running queries on the database, use only the column names that you need to retrieve. This can reduce network traffic and disk operations. When running an insert action query, use the columns list into which to insert instead of the table name (when you want to insert data in all the current columns). This way, if new columns are added to the table, your query will still work.
ReferencesW3C-Introduction to XHTML
http://www.w3schools.com/xhtml/xhtml_intro.asp
NYPL Online Style Guide: XHTML and CSS
http://www.nypl.org/styleguide/xhtml/index.html
Better Living through XHTML
By, Jeffery Zeldman
http://www.alistapart.com/stories/betterliving/
Good practices in database design
http://www.interaktonline.com/Support/Articles/Details
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