WebFund 2024F Lecture 3 - Revision history

Soma at 02:49, 17 September 2024

2024-09-17T02:49:24Z

← Older revision		Revision as of 02:49, 17 September 2024
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	==Video==		==Video==

	Video from the lecture given on September 12, 2024 is ~~NOT YET~~ available ~~but will be shortly here~~:		Video from the lecture given on September 12, 2024 is now available:
	* [https://homeostasis.scs.carleton.ca/~soma/webfund-2024f/lectures/comp2406-2024f-lec03-20240912.m4v video]		* [https://homeostasis.scs.carleton.ca/~soma/webfund-2024f/lectures/comp2406-2024f-lec03-20240912.m4v video]
	* [https://homeostasis.scs.carleton.ca/~soma/webfund-2024f/lectures/comp2406-2024f-lec03-20240912.cc.vtt auto-generated captions]		* [https://homeostasis.scs.carleton.ca/~soma/webfund-2024f/lectures/comp2406-2024f-lec03-20240912.cc.vtt auto-generated captions]

Soma: /* Notes */

2024-09-12T17:04:00Z

Notes

← Older revision		Revision as of 17:04, 12 September 2024
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	<pre>		<pre>
			Lecture 3
			---------

			Deno & JavaScript

			Technologies of the web: HTML, CSS, JavaScript
			- HTML is for defining the structure of a page, providing content
			- CSS is for styling
			- JavaScript is for interactivity (code) in a page

			==> this is all "frontend stuff"

			Originally, the web was just HTML & HTTP
			- with HTTP being the networking protocol


			So the web is a client-server architecture
			- web servers & web clients
			- a browser is a web client
			- web server is the "backend"
			- web client is the "frontend"

			So when you type in a URL or click on a link
			- the client opens a connection to the designated server
			- it then requests a resource from the server

			Structure of a URL

			https://homeostasis.scs.carleton.ca/wiki
			^^^^^^^^ Protocol
			^^^^^^^^^^^^^^^^^^^^^^^^^^^ Hostname
			^^^^^ Resource
	Hostname is defined by DNS <--- can talk about later		Hostname is defined by DNS <--- can talk about later

Soma at 17:03, 12 September 2024

2024-09-12T17:03:34Z

← Older revision		Revision as of 17:03, 12 September 2024
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	~~Note that this~~ lecture will be ~~asynchronous~~ for ~~most~~ of you, as it is ~~being recorded earlier~~ due ~~to Anil~~'s ~~travel schedule~~.		==Video==

			Video from the lecture given on September 12, 2024 is NOT YET available but will be shortly here:
			* [https://homeostasis.scs.carleton.ca/~soma/webfund-2024f/lectures/comp2406-2024f-lec03-20240912.m4v video]
			* [https://homeostasis.scs.carleton.ca/~soma/webfund-2024f/lectures/comp2406-2024f-lec03-20240912.cc.vtt auto-generated captions]

			==Notes==

			<pre>
			Hostname is defined by DNS <--- can talk about later

			GET <URL> <---- that's 90+% of HTTP requests


			Really, HTTP was designed as a file transfer protocol
			- connect to a host, ask for a file
			- request and response can contain some metadata, e.g. what type of file is it

			The cool thing about the web was that it could combine multiple files into one document
			- HTML file could have <img> tags which included images
			- so you had text + images


			For the modern web, you're sometimes downloading files, but for dynamic content you're downloading the output of a program

			So, to do modern web dev, you need to have a programming language for the server (backend) along with a programming language + content for the client (HTML, CSS, JavaScript)

			So what language for the server (backend)? There have been many:
			- Perl
			- PHP
			- Python
			- Ruby
			- Java
			- C#

			and many more. Basically any programming language can be used for web server side code.

			But we have to cover JavaScript in this course, because it is the language of the client. Why not also use it for the server? That's what we are doing in this class.
			- has some other benefits beyond us just having to learn 1 vs 2 languages for programming here

			So, when we want a server-side language, we want a language for generating HTML (basically).
			- so needs to be good at dealing with text

			Should also probably be more "dynamic", i.e., not need to be compiled
			(but that is no longer the case)


			(Coffeescript), typescript - used in the client rather than JavaScript
			- but these compile down to JavaScript

			There's also a way to run arbitrary code in the browser
			- webassembly, i.e., compile code to webassembly
			- but webassembly code still needs some JavaScript currently to work in a browser


			I had mentiend SQL before, where does that fit into this picture?

			So, we have many frontends (browsers) connecting to a backend, requesting content
			- if it is just static files, no problem
			- but what if it is data that changes?

			Concurrency becomes an issue
			- ever had two programs try to change the same file on disk?
			- so, so easy for there to be different versions, for one to save the file
			and the other to lose its changes

			Idea: use a technology that has been developed for dealing with concurrent access to data - databases

			frontend <->
			frontend <-> backend server <-> backend database
			frontend <->

			relational databases
			- first big application: airline reservations
			- make sure payments, customer info, and flight manifests are in sync

			SQL is the language of relational databases

			When are tutorials due?
			- must be finished by the associated assignment

			So A1 will require T1, T2, so T1, T2, & A1 must all be completed by A1's due date.
			- but you really don't want to fall behind
			- can only get checked off by talking to a TA
			</pre>

Soma: Created page with "Note that this lecture will be asynchronous for most of you, as it is being recorded earlier due to Anil's travel schedule."

2024-09-12T17:01:20Z

Created page with "Note that this lecture will be asynchronous for most of you, as it is being recorded earlier due to Anil's travel schedule."

New page

Note that this lecture will be asynchronous for most of you, as it is being recorded earlier due to Anil's travel schedule.