INFO 1012 Chap.6 HTML, CSS and the Document Object Model

HTML, CSS and the Document Object Model

Define HTML

The course material gives this chapter a concrete anchor: The web sequence progresses from HTML to JavaScript and DOM manipulation. That HTML anchor controls how CSS is explained and how DOM is tested in changed practice.

HTML, CSS and the Document Object Model turns HTML, CSS and DOM into executable reasoning.

The chapter's practical target is to build a structured page whose presentation and scripted behaviour remain separable, so every explanation should connect syntax to program state, control flow and observable output.

Treat HTML as a precise program object, not a loose label. Identify the value or responsibility of HTML before execution, then trace what can read it, change it or depend on it.

This makes state changes visible before they become debugging guesses.

Use CSS to explain the program's next move. Work through one representative CSS input by hand and name the branch, iteration or call that follows. If the CSS trace cannot be stated, the code may run by accident rather than by understood design.

Trace CSS

Bring in DOM as the test of structure.

Compare normal, boundary and invalid inputs for DOM; state the expected behaviour first; then use the mismatch between expectation and result to localise the defect.

For the application — build a structured page whose presentation and scripted behaviour remain separable — write the smallest complete example that exposes the rule.

Explain why the DOM result works, what would break it and how the program should signal or recover from that failure.

Before running an example involving HTML, make a trace table with the important state before and after each operation. Include the value associated with HTML, the control decision governed by CSS and the output or object affected by DOM.

The HTML table turns an unexplained result into a sequence that can be tested one transition at a time.

Test three inputs: an ordinary case, a boundary case and an invalid case. State the expected DOM result for each before execution, then compare it with what the program actually does.

A useful test of CSS isolates one rule; changing several conditions at once cannot reveal which condition caused the failure.

Test with DOM

Practise explaining the solution without reading the code.

For INFO 1012, name the data representation, the control flow, the responsibility of each function or class and the reason the chosen design supports build a structured page whose presentation and scripted behaviour remain separable.

This DOM rehearsal matters when a written test or interview asks why the program works rather than whether it produces one correct output.

A complete response should make the task visible before the detail: identify what must be decided, define the relevant terms, connect the evidence to CSS, and use DOM to test the result.

The final sentence about DOM should answer the question actually asked rather than merely repeat the topic.

The controlling limit is specific: visual resemblance does not prove semantic structure, accessibility or robust behaviour.

Keep that DOM limit beside the worked example, because it separates a careful INFO 1012 answer from one that sounds confident but claims more than the task or evidence supports.

For revision, retrieve HTML, CSS and DOM without notes, explain their relationship aloud, then complete a changed version of the application: build a structured page whose presentation and scripted behaviour remain separable.

Record the first failed CSS reasoning move and repair it before attempting another case.

What this chapter covers

• 01

  HTML

• 02

  CSS

• 03

  DOM

• 04

  Applying HTML

• 05

  Limits of CSS and DOM

Repair an interactive heading

Key terms

HTML

Markup defining document structure and semantics. This chapter uses the concept when students build a structured page whose presentation and scripted behaviour remain separable. Use this definition when the task is to build a structured page whose presentation and scripted behaviour remain separable.

CSS

Rules controlling presentation of selected document elements. It helps explain the reasoning required to build a structured page whose presentation and scripted behaviour remain separable. Use this definition when the task is to build a structured page whose presentation and scripted behaviour remain separable.

DOM

Programmable tree representation of a loaded document. Its limit matters because visual resemblance does not prove semantic structure, accessibility or robust behaviour. Use this definition when the task is to build a structured page whose presentation and scripted behaviour remain separable.

HTML, CSS and the Document Object Model FAQ

Exam move

Reconstruct the relationship among HTML, CSS and DOM; complete the chapter application without notes; then test the result against this limit: visual resemblance does not prove semantic structure, accessibility or robust behaviour.

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