RxJS–Unsubscribe automatically –part 47

I am searching for a simple method to unsubscribe from Observables. Some of methods are detailed here : https://blog.bitsrc.io/6-ways-to-unsubscribe-from-observables-in-angular-ab912819a78f

I do not want

  1. remember to unsubscribe
  2. being forced to use html ( the async pipe)
  3. take operator – I want later to cache first data and then make the http call
  4. first operator – same with 3
  5. decorator – seems ok.
  6. tsLint – no, can be easy to disable

 

So Decorator it is. More reading

https://www.typescriptlang.org/docs/handbook/decorators.html

https://netbasal.com/automagically-unsubscribe-in-angular-4487e9853a88

Added code the autoUnsub

export function AutoUnsub( constructor ) {

const original = constructor.prototype.ngOnDestroy;

console.log(‘from unsubscribe’);

constructor.prototype.ngOnDestroy = function() {

// tslint:disable-next-line: forin

for ( const prop in this ) {

const property = this[ prop ];

if ( property && (typeof property.unsubscribe === ‘function’) ) {

console.log(‘unsubscribe !’);

property.unsubscribe();

}

}

console.log(‘finish unsub’);

// tslint:disable-next-line: no-unused-expression

original && typeof original === ‘function’ && original.apply(this, arguments);

};

}

Modified code to make property of unsubscribe, e.g. from

this.banksService.GetBanksIds().subscribe(

it=>{

console.log(it.length);

this.banks=it;

},

err=> window.alert(“error:”+ JSON.stringify(err))

)

}

to

banksObs: Observable<string[]>;

//ommitted code

this.banksObs = this.banksService.GetBanksIds();

this.banksObs.subscribe(

it => {

console.log(it.length);

this.banks = it;

},

err => window.alert(‘error:’ + JSON.stringify(err))

);

Created also a new component, for programmers, in order to observe the unsubscribe moving from component to component,

See commit https://github.com/ignatandrei/InfoValutar/commit/66e358848652ce761cb6ef2d69a460f052b12e09

Infovalutar

And one hour passes...
(This is the result of 1 hour per day auto-challenge as a full cycle developer for an exchange rates application)
( You can see the sources at https://github.com/ignatandrei/InfoValutar/ )