CRUD application with local store
> Author: Thomas Laforge
## Information
Communicating and having a global/local state in sync with your backend is the heart of any application. You will need to master those following best practises to build strong and reliable Angular Application.
## Statement
In this exercice, you have a small CRUD application, which get a list of TODOS, update and delete some todo.
Currently we have a working exemple but filled with lots of bad practices.
### Step 1: refactor with best practices
What you will need to do:
- Avoid **any** as a type. Using Interface to leverage Typescript type system prevent errors
- Use a **separate service** for all your http calls and use a **BehaviourSubject** for your todoList
- Use **AsyncPipe** to suscribe to your todo list. _(Let you handle subscription, unsuscription and refresh of the page when data has changed)_, avoir manual subscribe when it's not needed
- Don't **mutate** data
```typescript
// Avoid this
this.todos[todoUpdated.id - 1] = todoUpdated;
// Prefer something like this, but need to be improved because we still want the same order
this.todos = [
...this.todos.filter((t) => t.id !== todoUpdated.id),
todoUpdated,
];
```
- Use **ChangeDectection.OnPush**
### Step 2: Improve
- Add a **Delete** button: _Doc of fake API_
- Handle **errors** correctly. _(Globaly)_
- Add a Global **loading** indicator. _You can use MatProgressSpinnerModule_
### Step 3: Maintainability!! add some test
- Add 2/3 tests
### Step 4: Awesomeness!!! master your state.
- Use the **component store of ngrx** as a local state of your component. _(or any other 3rd Party lib)_
- Have a **localize** Loading/Error indicator, e.g. only on the Todo being processed and **disable** all buttons of the processed Todo. _(Hint: you will need to create an ItemComponent)_
## Submitting your work
1. Fork the project
2. clone it
3. npm install
4. **nx serve crud**
5. _...work On it_
6. Commit your work
7. Submit a PR with a title beginning with **Answer:3** that I will review and other dev can review.
_You can ask any question on_ 