CS257 Software Design
Monday, 12 May 2025

+ Web page sequence of events
When you point your browser at an index.html URL
- Browser connects to web server (TCP connection)
- Browser sends GET /path/to/index.html
- Server sends the requested file index.html back
- Browser parses the index.html file
    i.e. determines the structure of the file
    - Identifies other resources it needs to retrieve from the server
    - Issues GET requests for those resources
    - Builds a data structure called the Document Object Model (DOM)
- Rendering the page starts early, gets updated as new info arrives
    from later GET requests

- Fetch, parse, act, render
- Construction of the DOM
- Multi-threaded retrieval of other resources
- Role of CSS

+ HTML/CSS lab
- CSS structure
    selector { style; style; style; ... }
- Keep working on this!
- Play around.

+ Warning
- Professional web dev often doesn't use CSS as directly as this
    (sometimes it does...)
- Ditto for HTML and Javascript

+ SQL injection
- Easy to demo: data leak
- BUT: you can often also use a SQL injection to login to the server
    without a username and password

+ Next assignment