perl_24_HTML_1.pptVIP

Chapter 24 — Bonus: Introduction to HyperText Markup Language 4: Part I 24.1 Introduction Hypertext Markup Language (HTML) Markup Language Identifies elements of a page Rendered by Web Browser 24.2 Markup Languages HTML Markup Elements Delimited by tags Keywords enclosed by angle brackets All tags must be closed Not Case Sensitive All lowercase recommended 24.3 Editing HTML HTML Source Code HTML documents Created in text editor Notepad in Windows Vi or Emacs in UNIX Saved as .html or .htm file extension Errors Not Fatal Rendered page may display incorrectly 24.3 Editing HTML (cont.) HTML Source Code Home Page Named index.html Browser automatically loads index.html First page user sees 24.4 Common Elements HTML Elements Upcoming Example Fig. 24.1 Basic HTML file.Line 1Line 3 Lines 5-6Line 8Line 9Line 12Line 14 Fig 24.1 Output 24.5 Headers Header Elements Delineate page sections and sub-sections Elements h1 – h6 define headers Sizes vary between browsers Fig. 24.2 Header elements h1 through h6.Lines 14-19 Output for Fig. 24.2 24.6 Linking Hyperlinks Anchors Text or images Requires attribute href Demonstrated in upcoming example Fig. 24.3 Linking to other Web pages.Line 19Line 19Line 19 Output for Fig. 24.3 mailto: tells Web browser to load default e-mail client with given address Fig. 24.4 Linking to an email address.Line 14 Output for Fig. 24.4 24.7 Images Images May be hyperlink anchors Element img attributes Attribute src Image location Attribute height Image height Attribute width Image width Attribute alt Defines text if image cannot be displayed Fig. 24.5 Placing images in HTML files.Line 14 Output for Fig. 24.5 Fig. 24.6 Using images as link anchors.Line 16Line 17 Fig. 24.6 Using images as link anchors. (Part 2) Output for Fig. 24.6 24.8 Special Characters and More Line Breaks Special Characters Format: code; code is abbreviated name or hex code Examples: amp; = copy; = ? 24.8 Special Characters and Mor