3.02B Authoring Languages 3.02 Develop webpages.
Authoring Languages Used to control the appearance and functionality of webpages when displayed in a browser Examples include: HTML (HyperText Markup Language) XML (eXtensible Markup Language) XHTML (eXtensible HTML)
HTML HyperText Markup Language Example of HTML code <html> <title>Student Website</title> <b>Welcome to my website!</b> </html> HyperText Markup Language First and still primary language for developing webpages/sites. Uses codes, or tags, to instruct the browser how to display text and images. Is platform independent.
XML Describes data types to facilitate data processing eXtensible Markup Language Describes data types to facilitate data processing Designed to carry data, not to display it Allows the author to define tags to identify each data entry so that the data can be easily imported into other applications Metadata—data about data Example of XML code <weather> <city>Atlanta</city> <state>Georgia</state> <temp>75</temp> </weather>
XHTML eXtensible HyperText Markup Language Combination of HTML and XML Allows the designer to mix HTML and XML so that browsers can display and manage data correctly Originally intended to replace HTML as dominant authoring language Places restrictions on HTML tags so that code is cleaner and can display data as the author intended Requires all HTML tag sets be closed Requires lowercase tags Many devices can’t interpret bad HTML code (mobile phones, PDAs) Teacher Note: The problem was that different browsers began to add HTML tags that only their browser would support. For example, Netscape’s browser would recognize the <blink> tag which would make text blink. Microsoft’s browser (Internet Explorer) did not recognize this tag. Soon, web developers found themselves faced with having to learn which tags would work in which browsers and design their websites with these compatibility issues in mind. This is why the W3C stepped in and began creating standards for web development. They wanted to create guidelines for developing web pages so that pages would display the same in all browsers. XHTML was intended to separate the data (information) from the formatting (styles). Several tags that were used to format text were deprecated (recommended for deletion from future coding languages) in favor of using style sheets to perform the formatting. Even though the upcoming recommendation from the W3C will be HTML 5, it will still follow many of the coding guidelines used in writing XHTML.
Style Sheets Describe how browsers should present or display information on a webpage. Give web developers more control over layout and page formatting. Cascading Style Sheets (CSS) is a popular style sheet language.
CSS Cascading Style Sheets <html> <head> <style type="text/css"> h1 {color: #00ff00} h2 {color: #dda0dd} p {color: rgb(0,0,255)} </style> </head> <body> <h1>This is header 1</h1> <h2>This is header 2</h2> <p>This is a paragraph</p> </body> </html> Cascading Style Sheets Separates content from appearance and gives web authors more control over layout and page format CSS code instructs the Web browser how to format each item.
Pros and Cons of CSS Advantages Disadvantages One style sheet can control the formatting for multiple webpages. An entire website can be reformatted by editing one CSS file. Styles can also be set internally. The CSS code is keyed in the header section of the html document. Disadvantages May alter the ability of some devices to accurately read and display information.
Text Editors Allow developers to write code in plain text. Examples: Notepad Notepad2 Wordpad Microsoft Word should not be used to create webpages.