HTML Forms and Scripts

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HTML Forms and Scripts

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Session overview

• What are forms?
• Static vs dynamic
• Client-side scripts
• JavaScript

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HTML Forms

• HTML Forms were the first way for users to
  interact with the Web
• controls (input fields)
• form submission
• form processing (nothing to do with HTML!)

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HTML Forms

• ltFORMgt
• action
• method
• enctype
• accept
• accept-charset

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Static vs Dynamic

• Static
• page appears exactly as it was encoded, nothing
  changes
• Dynamic
• page is compiled, or able to be changed

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Scripts server-side vs client-side

• Server-side
• the first type possible on the Web
• action occurs at the server
• Client-side
• generally easier to implement
• may be prepared and implemented offline
• action occurs on the client side (browser)

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Examples of client-side scripts

• JavaScript (most common)
• VBScript (Microsoft)
• Java applets - can be server-side or client-side

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Embedding scripts in HTML

• ltSCRIPTgt
• can appear anywhere in the HTML document (but
  best in the ltHEADgt)
• the script can be linked (like a separate style
  sheet)
• ltscript typetext/javascript languageJavaScrip
  t srcrollovers.jsgt

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JavaScript

• Can be used to make Web page tricks like image
  rollovers, form validation, calculations etc
• Developed by Netscape to be simple, cross-browser
  scripting language for Web
• Syntax based on C - a good starting point to
  learn other programming languages
• JavaScript is not Java

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Example JavaScript rollover...

• Satellite Dispatch (http//www.toysatellite.org/ne
  ws)

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Dynamic HTML / dHTML / DHTML

• HTML elements (or objects) that can change after
  the document has loaded in browser
• DHTML HTMLCSS scripts (generally, JavaScript)

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Example Dynamic HTML

• Auslaender Micro http//www.toysatellite.org/agart
  on/MA/project/micro02/splash.htm