Mixing code and attributes in TypeScript class
I have a simple TypeScript class defined like this:
export class Piece {
Qty: number;
Weight: number;
Type: string;
totalWeight() {
return Qty * Weight;
}
}
And, I have an Angular 5 service that has a method like this:
get(id: number) {
return this.http.get<Piece>(myAPIURL + id);
}
And my Angular code calls this as follows:
const myPiece: Piece;
this.myService.get(2).subscribe(data => myPiece = data);
When all is said and done, the variable 'myPiece' contains the correct data; however, there is no totalWeight() method attached to it. I think I understand why (because the server returned the data/attributes, but obviously no code). But is there a way to somehow unite the data and the code/methods again?
My background is with C# objects, and I'm still new to Java/TypeScript. I'm guessing this may have something to do with the prototypical inheritance in JavaScript?
Any help?
angular typescript
asked Nov 23 '18 at 21:29
Rob SchripsemaRob Schripsema
135
add a comment |
I have a simple TypeScript class defined like this:
export class Piece {
Qty: number;
Weight: number;
Type: string;
totalWeight() {
return Qty * Weight;
}
}
And, I have an Angular 5 service that has a method like this:
get(id: number) {
return this.http.get<Piece>(myAPIURL + id);
}
And my Angular code calls this as follows:
const myPiece: Piece;
this.myService.get(2).subscribe(data => myPiece = data);
When all is said and done, the variable 'myPiece' contains the correct data; however, there is no totalWeight() method attached to it. I think I understand why (because the server returned the data/attributes, but obviously no code). But is there a way to somehow unite the data and the code/methods again?
My background is with C# objects, and I'm still new to Java/TypeScript. I'm guessing this may have something to do with the prototypical inheritance in JavaScript?
Any help?
angular typescript
asked Nov 23 '18 at 21:29
Rob SchripsemaRob Schripsema
135
add a comment |
I have a simple TypeScript class defined like this:
export class Piece {
Qty: number;
Weight: number;
Type: string;
totalWeight() {
return Qty * Weight;
}
}
And, I have an Angular 5 service that has a method like this:
get(id: number) {
return this.http.get<Piece>(myAPIURL + id);
}
And my Angular code calls this as follows:
const myPiece: Piece;
this.myService.get(2).subscribe(data => myPiece = data);
When all is said and done, the variable 'myPiece' contains the correct data; however, there is no totalWeight() method attached to it. I think I understand why (because the server returned the data/attributes, but obviously no code). But is there a way to somehow unite the data and the code/methods again?
My background is with C# objects, and I'm still new to Java/TypeScript. I'm guessing this may have something to do with the prototypical inheritance in JavaScript?
Any help?
angular typescript
asked Nov 23 '18 at 21:29
Rob SchripsemaRob Schripsema
135
I have a simple TypeScript class defined like this:
export class Piece {
Qty: number;
Weight: number;
Type: string;
totalWeight() {
return Qty * Weight;
}
}
And, I have an Angular 5 service that has a method like this:
get(id: number) {
return this.http.get<Piece>(myAPIURL + id);
}
And my Angular code calls this as follows:
const myPiece: Piece;
this.myService.get(2).subscribe(data => myPiece = data);
When all is said and done, the variable 'myPiece' contains the correct data; however, there is no totalWeight() method attached to it. I think I understand why (because the server returned the data/attributes, but obviously no code). But is there a way to somehow unite the data and the code/methods again?
My background is with C# objects, and I'm still new to Java/TypeScript. I'm guessing this may have something to do with the prototypical inheritance in JavaScript?
Any help?
angular typescript
angular typescript
asked Nov 23 '18 at 21:29
Rob SchripsemaRob Schripsema
135
asked Nov 23 '18 at 21:29
Rob SchripsemaRob Schripsema
135
asked Nov 23 '18 at 21:29
Rob SchripsemaRob Schripsema
135
asked Nov 23 '18 at 21:29
Rob SchripsemaRob Schripsema
135
asked Nov 23 '18 at 21:29
Rob SchripsemaRob Schripsema
135
135
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
you need to actually instantiate the class from the http call. TypeScript is just javascript with type hinting, not actual casting can be done, because javascript doesn't have this. So to make something a certain class, you really have to instantiate this with the new keyword
get(id: number) {
return this.http.get<Piece>(myAPIURL + id).pipe(
map((data) => ({ ...new Piece(), ...data}))
)
}
or
map((data) => Object.assign(new Piece(), data))
Whatever you find more legible
answered Nov 23 '18 at 21:44
PierreDucPierreDuc
30.2k56078
Exactly what I was looking for! I'll give it a try and see how it goes.
– Rob Schripsema
Nov 23 '18 at 22:38
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 need to actually instantiate the class from the http call. TypeScript is just javascript with type hinting, not actual casting can be done, because javascript doesn't have this. So to make something a certain class, you really have to instantiate this with the new keyword
get(id: number) {
return this.http.get<Piece>(myAPIURL + id).pipe(
map((data) => ({ ...new Piece(), ...data}))
)
}
or
map((data) => Object.assign(new Piece(), data))
Whatever you find more legible
answered Nov 23 '18 at 21:44
PierreDucPierreDuc
30.2k56078
Exactly what I was looking for! I'll give it a try and see how it goes.
– Rob Schripsema
Nov 23 '18 at 22:38
add a comment |
you need to actually instantiate the class from the http call. TypeScript is just javascript with type hinting, not actual casting can be done, because javascript doesn't have this. So to make something a certain class, you really have to instantiate this with the new keyword
get(id: number) {
return this.http.get<Piece>(myAPIURL + id).pipe(
map((data) => ({ ...new Piece(), ...data}))
)
}
or
map((data) => Object.assign(new Piece(), data))
Whatever you find more legible
answered Nov 23 '18 at 21:44
PierreDucPierreDuc
30.2k56078
Exactly what I was looking for! I'll give it a try and see how it goes.
– Rob Schripsema
Nov 23 '18 at 22:38
add a comment |
you need to actually instantiate the class from the http call. TypeScript is just javascript with type hinting, not actual casting can be done, because javascript doesn't have this. So to make something a certain class, you really have to instantiate this with the new keyword
get(id: number) {
return this.http.get<Piece>(myAPIURL + id).pipe(
map((data) => ({ ...new Piece(), ...data}))
)
}
or
map((data) => Object.assign(new Piece(), data))
Whatever you find more legible
answered Nov 23 '18 at 21:44
PierreDucPierreDuc
30.2k56078
you need to actually instantiate the class from the http call. TypeScript is just javascript with type hinting, not actual casting can be done, because javascript doesn't have this. So to make something a certain class, you really have to instantiate this with the new keyword
get(id: number) {
return this.http.get<Piece>(myAPIURL + id).pipe(
map((data) => ({ ...new Piece(), ...data}))
)
}
or
map((data) => Object.assign(new Piece(), data))
Whatever you find more legible
answered Nov 23 '18 at 21:44
PierreDucPierreDuc
30.2k56078
answered Nov 23 '18 at 21:44
PierreDucPierreDuc
30.2k56078
answered Nov 23 '18 at 21:44
PierreDucPierreDuc
30.2k56078
answered Nov 23 '18 at 21:44
PierreDucPierreDuc
30.2k56078
30.2k56078
Exactly what I was looking for! I'll give it a try and see how it goes.
– Rob Schripsema
Nov 23 '18 at 22:38
add a comment |
Exactly what I was looking for! I'll give it a try and see how it goes.
– Rob Schripsema
Nov 23 '18 at 22:38
Exactly what I was looking for! I'll give it a try and see how it goes.
– Rob Schripsema
Nov 23 '18 at 22:38
Exactly what I was looking for! I'll give it a try and see how it goes.
– Rob Schripsema
Nov 23 '18 at 22:38
add a comment |
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