Lazy property for http get request
I would like to create a lazy property in a service, meaning - I would like to have a (lets say) boolean member which should be initialized by a get request.
The property checks whether the member is already initialized:
1. If so - it returns the value or an observable of the value.
2. If not - the get request is executed, the member is being initialed and then the value (or an observable) is being rerturned.
this.getIsTrue is an http get request.
See my code in the service:
isTrue: boolean = null;
get IsTrue() : Observable<boolean> // It can return even boolean and not
observablle
{
if (this.isTrue!= null)
{
return of(this.ifTrue); // can return even boolean and not
observablle
}
else
{
this.getIsTrue().subscribe(result => {
this.isTrue = result;
return of(this.isTrue);});
}
}
rxjs angular2-services angular-observable
asked Nov 14 '18 at 11:54
Guy EGuy E
13517
add a comment |
I would like to create a lazy property in a service, meaning - I would like to have a (lets say) boolean member which should be initialized by a get request.
The property checks whether the member is already initialized:
1. If so - it returns the value or an observable of the value.
2. If not - the get request is executed, the member is being initialed and then the value (or an observable) is being rerturned.
this.getIsTrue is an http get request.
See my code in the service:
isTrue: boolean = null;
get IsTrue() : Observable<boolean> // It can return even boolean and not
observablle
{
if (this.isTrue!= null)
{
return of(this.ifTrue); // can return even boolean and not
observablle
}
else
{
this.getIsTrue().subscribe(result => {
this.isTrue = result;
return of(this.isTrue);});
}
}
rxjs angular2-services angular-observable
asked Nov 14 '18 at 11:54
Guy EGuy E
13517
add a comment |
I would like to create a lazy property in a service, meaning - I would like to have a (lets say) boolean member which should be initialized by a get request.
The property checks whether the member is already initialized:
1. If so - it returns the value or an observable of the value.
2. If not - the get request is executed, the member is being initialed and then the value (or an observable) is being rerturned.
this.getIsTrue is an http get request.
See my code in the service:
isTrue: boolean = null;
get IsTrue() : Observable<boolean> // It can return even boolean and not
observablle
{
if (this.isTrue!= null)
{
return of(this.ifTrue); // can return even boolean and not
observablle
}
else
{
this.getIsTrue().subscribe(result => {
this.isTrue = result;
return of(this.isTrue);});
}
}
rxjs angular2-services angular-observable
asked Nov 14 '18 at 11:54
Guy EGuy E
13517
I would like to create a lazy property in a service, meaning - I would like to have a (lets say) boolean member which should be initialized by a get request.
The property checks whether the member is already initialized:
1. If so - it returns the value or an observable of the value.
2. If not - the get request is executed, the member is being initialed and then the value (or an observable) is being rerturned.
this.getIsTrue is an http get request.
See my code in the service:
isTrue: boolean = null;
get IsTrue() : Observable<boolean> // It can return even boolean and not
observablle
{
if (this.isTrue!= null)
{
return of(this.ifTrue); // can return even boolean and not
observablle
}
else
{
this.getIsTrue().subscribe(result => {
this.isTrue = result;
return of(this.isTrue);});
}
}
rxjs angular2-services angular-observable
rxjs angular2-services angular-observable
asked Nov 14 '18 at 11:54
Guy EGuy E
13517
asked Nov 14 '18 at 11:54
Guy EGuy E
13517
asked Nov 14 '18 at 11:54
Guy EGuy E
13517
asked Nov 14 '18 at 11:54
Guy EGuy E
13517
asked Nov 14 '18 at 11:54
Guy EGuy E
13517
13517
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
You can use tap if you need to make side-effects instead of subscribing to it:
return this.getIsTrue().pipe(
tap(result => this.isTrue = result),
);
answered Nov 14 '18 at 12:01
martinmartin
43.6k1187131
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
You can use tap if you need to make side-effects instead of subscribing to it:
return this.getIsTrue().pipe(
tap(result => this.isTrue = result),
);
answered Nov 14 '18 at 12:01
martinmartin
43.6k1187131
add a comment |
You can use tap if you need to make side-effects instead of subscribing to it:
return this.getIsTrue().pipe(
tap(result => this.isTrue = result),
);
answered Nov 14 '18 at 12:01
martinmartin
43.6k1187131
add a comment |
You can use tap if you need to make side-effects instead of subscribing to it:
return this.getIsTrue().pipe(
tap(result => this.isTrue = result),
);
answered Nov 14 '18 at 12:01
martinmartin
43.6k1187131
You can use tap if you need to make side-effects instead of subscribing to it:
return this.getIsTrue().pipe(
tap(result => this.isTrue = result),
);
answered Nov 14 '18 at 12:01
martinmartin
43.6k1187131
answered Nov 14 '18 at 12:01
martinmartin
43.6k1187131
answered Nov 14 '18 at 12:01
martinmartin
43.6k1187131
answered Nov 14 '18 at 12:01
martinmartin
43.6k1187131
43.6k1187131
add a comment |
add a comment |
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