2. XHTML, CSS, Good web and database design practices Snehal Monteiro For CIS 764

3. Outline What You’re In For Why XHTML & CSS? XHTML CSS Making the Transition The Future Good Web and Database design practices

4. 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

5. Why XHTML & CSS? Garbage code is…uh…garbage! Information encoded in XHTML can be more easily migrated as technology changes XHTML is a good step forward to learning XML You can easily make global changes to how your documents display There are user benefits to separating information from presentation

6. 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

7. 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!!!

8. XHTML Benefits A painless transition to more advanced technology (XML) Clean, more logical markup Increased interoperability Greater accessibility

9. 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 user interface, 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

10. How can I convert to XHTML?? Very few simple rules…that’s it! All tags must be in lowercase: All tags must end: Even empty tags: = All tags must properly nest: This is an anchor. All attribute values must be quoted:

11. XHTML: More Rules Attribute minimization is forbidden: becomes… You must use a document type declaration: Transitional: Strict: And add a namespace declaration to :

12. Evolution of XHTML standards HTML 4.0 Transitional XHTML Basic XHTML Transitional XHTML Strict There are online validation tools available which check conformance to standards-

15. 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

16. Benefits of CSS Conserve 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)

17. CSS: Rule Structure h1 { color: purple; } h1 { font-family: Optima, Arial, sans-serif; } propertyvalue begins and ends the declaration property/valueseparator ends every property/ value pair declarationselector

18. CSS Rule Example body { background: #FFFFFF; color: black; margin-left: 5%; margin-right: 5%; font-family: Tahoma, Optima, Arial, sans-serif; }

19. Where do you put styles? In-line - add to HTML tag Embedded style sheets External style sheets

20. In-line Similar to adding attributes to html tags Disadvantages decreased accessibility increased file size harder to update

21. Embedded style sheets  Put rules between style tags  Put in head section  Add html comment tags  Use when single document has unique style

22. External style sheets Save rules in external file Advantages ease of maintenance use less disk space increase accessibility

23. Class selector & attribute To create rules that can be applied to a variety of html tags.bar {color: maroon; font-size: smaller; background-color: yellow;} … text … link

24. CSS: Diagram of Precedence External Style Sheet [call to external stylesheet] [styles embedded inside the document] XHTML File 1) 2) Generalized order of precedence, all other things being equal

25. http://jigsaw.w3.org/css-validator/

26. Making the Transition: Tidy HTML Tidy is free software that can read your HTML and output a much better file by: Automatically fixing some errors Changing uppercase tags to lowercase Indenting your code to make to make it more readable Quote all attribute values And other things, depends on configuration file An error report may also be generated that can identify remaining problems

27. 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

28. 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!

29. Adding hit counters to your web- site for free Just register at www.google.com/analytics 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

31. Good web-design practices: Comment your code! Use XHTML rules and CSS Use AJAX to enhance user interaction and increase speed Archive code before making any changes to the current web-site Re-use code: eg: Database connection code, reusable javascript subroutines Use lower-case more than upper-case, it looks more attractive and subtle

32. Good database design practices Comment your code! Don’t store big binary files in the database Correctly identify which fields require data If 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.

33. 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.

34. References W3C-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

35. Thank-you! Questions ???