bf-separation-of-concerns
Separation of Concerns
“The most important principle in Software Engineering is the Separation of Concerns (SoC): The idea that a software system must be decomposed into parts that overlap in functionality as little as possible.”
Learning Objectives
- event-driven programming: identify the concept in a JS program via listeners & handlers
- entry points: describe what an entry point is, there are 2 kinds in the programs for this module - initialization & interaction. identify them in a program
- function roles: describe what function roles are and why they’re important. they can identify a function’s role given checklists for each role covered in this module:
- listeners: functions that attach event listeners to the DOM
- handlers: entry point for user interactions
- utils (utilities): pure functions to help do things with data
- components: render data into DOM elements to display for the user
- custom events: create custom events events in your components, passing useful data between components and handlers
- DOM access: You read and write values from the DOM in an event handler
- es5 vs. es6: You can demonstrate the change in developer-experience pre and post es6 by stepping through in the debugger and explaining differences in scoping (global vs. script, block vs. local, modules) between two programs with identical user experience but different implementations.
- Scope Hierarchy: You is comfortable navigating different scopes in the browser’s debugger to understand an existing application (script, module, closure, local, block)
- Code Splitting: You can use ES Modules to split your code into multiple files & folders according to function role, data, listeners and initialization. They can use generated dependency diagrams and documentation to understand and navigate this folder structure.
- Dependency Graphs: You can use a project’s dependency graph to understand how it is organized and to navigate the source code.
- Development Strategies: You can write development strategies that have all of the program’s state defined at the beginning, and separate each user story into interface and interaction tasks.
- Naming Functions: You can come up with clear and helpful names for the functions in your program. A good function name will take into account the function’s role and the program’s domain, like in the
/naming-variablesexercises from Debugging. - DOM manipulation: You can manipulate the DOM when implementing level-appropriate user interactions
- Isolating Components: You can use a
test.htmlfile to render your components with different inputs - Forms: You can do basic handling of form data via
event.target.form - Handling events: You can use the
eventargument to process user interactions, including bubbled events usingevent.target - Passing Component Unit Tests: You can write vanilla DOM component functions to pass provided unit tests
- refactoring: refactor a single-script tutorial-style web page into multiple files using imports and exports
- reverse-engineering: You can incrementally reverse-engineer a level-appropriate user interaction following these steps:
- init
- Listeners
- Handlers
- (possibly): Utils, Components, Custom Events
- From Spec: given user stories, You can develop a site from scratch using a template repository.
- Writing Component Unit Tests: You can write unit tests to validate your component functions using BDD syntax
Getting Started
How to study the code in this repo.
run scripts
### `npm run test -- path/to/file.spec.js` You can run tests in this repository using the `test` script, it will run all the tests in the path you provide. If you do `npm run test` or `npm run test -- ./` it will run every test in this repository. (there are a lot) ### `npm run format -- path` This script will format all of the code in the path you provide. ### Linting There is no linting script in this repository. It's for practice only, no need to check every detail. Your project starter repositories will have linting scripts.
Class recording
expand/collapse
### Week1 - [day1](https://youtu.be/IDCeq2z-_6Y) - [day3](https://youtu.be/wP3mCjZzHa8) - [day4](https://youtu.be/1RizIxUqeLE) - [day5](https://youtu.be/RieEjZMUTc4) ### Week2 - [day7](https://youtu.be/YOwPioc7mVo) - [day9](https://youtu.be/syvQtBaV36g) - [day10](https://youtu.be/RlrLe630-XE)