Chapter 4 HTML
Objectives Explain how HTML/XHTML are used and describe the difference between them Interpret HTML code Explain how HTML Forms are used in web applications Interpret HTML Forms Explain the purpose Cascading Style Sheets (CSS) Describe the different formats for CSS code Interpret CSS code
HTML HyperText Markup Language (HTML) is the language for writing web pages HTML/4 is the current version HTML/4 versions include –strict:strictly enforces syntax rules –traditional:allows informally accepted syntax –frameset:allows the use of HTML frames
XHTML XHTML is HTML expressed as an XML document Compared to HTML –XHTML has a more rigorous syntax, which is more machine-readable –XHTML contains more meta-information, i.e., information about the HTML document
HTML Syntax Each HTML element is defined by a tag, or pair of tags –tags are delimited by angle brackets: –tags may include attributes( name=“value” ) Paired tags have content –e.g., paragraph: Hello! Empty tags contain nothing –e.g.,,
Sample Web Page
XHTML Headings XHTML documents start in this form (version XHTML/1-strict) <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" " <html xmlns=" xml:lang="en" lang="en"> define XML version define XML document type start HTML document
element The first element of an HTML document is the element –defines a document title, among other things –document title appears in the browser title bar Eastern Hills Soccer League
Headings and Paragraphs Eastern Hills Soccer League EHSL Mission: to serve all children in the Hills area by providing an opportunity for them to grow up healthy, happy, and strong through participation in the world's greatest competitive sport. heading, level1 (1-6 available ) horizontal rule image paragraph (text)
Lists unordered (bullet) list ordered (numbered) list list item Current Team Standings This Week's Matches Contact Us
Hyperlinks Hyperlinks take the browser to other documents when clicked Format: …link text… –e.g., Current Team Standings
Tables An HTML table presents data in a grid format Table Caption R1,C1 R1,C2 R1,C3 R2,C1 R2,C2 R2,C3 R1,C1R1,C2R1,C3 R2,C1R2,C2R2,C3 Table Caption
HTML Forms An HTML Form presents a fill-in form for entering data Form controls include –text box, text area, and password box –check box –radio buttons –drop-down menus –submit buttons
Form tag
Text and Passwords
Check-box and Radio-Buttons
Drop-Down Menus
Submit Buttons
CSS Cascading Style Sheets is a technique for changing the appearance, or style, of web page elements Style may be defined in three ways: –in-line: along with an HTML element –internal style sheet:within an HTML document –external style sheet:outside of an HTML document
Style Elements The “style” of an element can include many visible attributes: –Color –Size –Font –Alignment –Decoration (underline, bold, etc.) –etc.
Style Definition Style attributes are defined as a set of “name: value” pairs, separated by “;” color: red; background: blue; align: left Each HTML element has its own set of relevant style attributes
In-Line Style In-line style is defined using the “style” attribute of an HTML element This paragraph is centered in blue
Internal Style Sheet An internal style sheet is defined in the heading of an HTML document –Delimited by …... p{ color: blue; text-align: center }
Internal Style Sheet An internal style sheet consists of a set of descriptors Each descriptor defines the style for one HTML element Descriptor format: h1{ text-align: center; color: brown } selector declaration block property name / value
Internal Style Sheet h1{ text-align: center; color: brown } The selector identifies one or more HTML elements to which the rule applies –multiple elements are comma-separated Property values in the declaration block apply to each instance of the selected HTML element(s) selector declaration block property name / value
Selectors Descriptors starting with "." define classes that can be referenced in document elements using the class attribute. number { text-align: right } 1234
Selectors Descriptors may also identify established psuedoclasses –e.g., a:hover is applied to hyperlinks only while under the cursor a:hover{ background: white }
Internal Style Sheet Example... h1 { color: brown; background-color: lightgray; border: solid gray; text-align:center; padding:.5em; }.strong { font-weight: bold; }.quote { margin-left: 1em; margin-right: 1em; } li { padding-top: 1ex; } a:hover { background-color: lightgray; }
External Style Sheet An external style sheet has the same format as an internal style sheet, but is stored in a separate document It is imported into a document with a tag...
CSS - Precedence When conflicting style attributes apply to an element, the closest one takes precedence External Style Sheet Internal Style Sheet In-line Style Attribute HTML Element
Review HTML XHTML HTML Forms Cascading Style Sheets In-line, internal, and external style sheets