Angular quick notes


FAQ

I regularly look for solutions to the following problems. For this reason I collected here questions and answers.
There is no logic in the order and the solution is more a quick note than a full article, if many questions are about the same subject I will create a separate page.

You are welcome to add questions / answers in the comments.

Node.js: I need multiple versions of Node.js installed on my machine ...

Use nvm

If you are using MacOS, https://formulae.brew.sh/formula/nvm:
brew install nvm
If you are using zsh (MacOS 10.15) you have to update .zshrc according to the documentation of Homebrew.

Commands

  • Install the latest node version: nvm install node
  • Use the latest node version: nvm use node
  • Install the latest LTS version: nvm install --lts
  • Install a specific version (e.g.): nvm install 10.10

List of node.js releases:
https://nodejs.org/en/download/releases/

NgRX: Can I Dispatch an event inside a reducer? How can I subscribe an action?

It should be avoided, this is an antipattern: https://stackoverflow.com/questions/36730793/can-i-dispatch-an-action-in-reducer

In my case the question come often because when I need to chain the events the 'shortcut' would be to start them in the reducer and not in the business code.

Example solution, in this case after an event occurred I want to load some data from the store and call a new action with this data:

constructor(public actions$: Actions, public store: Store<AppState>) { 
 
const observableOfTheEventToStart$ )  store.select(state => state.yourState); 
 
actions$.pipe( 
    ofType(YourActions.ActionSuccess), 
    mergeMap(() => observableOfTheEventToStart$), 
    map(resultEventToStart => this.store.dispatch(new SeconfActionToCall(resultEventToStart))) 
).subscribe(); 
 
} 

Drag Drop and Shift

This is usually used in tree structures / catalogs

insertAndShift(originalArray, fromIndex, toIndex) { 
    const cutFrom = originalArray.splice(fromIndex, 1)[0]; 
    originalArray.splice(toIndex, 0, cutFrom); 
 } 

How to check Angular CLI version

npm @angular/cli -v

How to check Angular version

npm @angular -v

How to uninstall Angular CLI

npm uninstall @angular/cli