I am developing a generic dropdown component. If the user enters a value not in the list, I want to return a new object of the same type in the itemSelected event. I need to preserve the methods as well as the properties - so just creating a generic object won't work. This needs to work even if the list is empty so it won't work to do something like Object.create(this.list[0]);
My work-around so far is to just pass a reference object, which I CAN use with Object.create but this seems lame.
The following snippet shows what I'm trying to do. Is there a way to do this or a better way to do what I want? Thanks - Jon
import { Component, OnInit, Input } from '@angular/core';
@Component({
selector: 'app-generic-new',
templateUrl: './generic-new.component.html',
styleUrls: ['./generic-new.component.scss']
})
export class GenericNewComponent implements OnInit {
ngOnInit(): void {}
@Input() type:any
createNewType():any {
// this is what I'm trying to do - but doesn't work
return new this.type();
}
}
Using Generics
class container<T> {
id: T;
key: T;
displayValue: T;
type : T;
}
//allows you to control the type, here we are allowing any, but could be person, address etc.
let myContainer = new container<any>();
myContainer.id = 0;
myContainer.key = "UserEnteredKey";
myContainer.displayValue = "UserEnteredDisplayValue;
myContiner.type //allow access to anything or a specific class type.
Not using generics.
class container{
id:number;
key:number;
displayValue:string;
type:any;
}
let myContainer = new contaier();
myContainer.number = 10;
myContainer.key = "UserEnteredKey";
myContainer.displayValue = "User Entered Display Value";
myContainer.type = {key:myContainer.key, display: myContainer.displayValue, doSomething: function(){//do something here.}}
Note that any of the values above can be computed instead of being static, for example IDs are usually computed.
@Input() type:container
createNewType():any {
// this is what I'm trying to do - but doesn't work
return
let myContainer = new container<any>();
myContainer.id = this.getNextID();
myContainer.key = "UserEnteredKey";
myContainer.displayValue = "UserEnteredDisplayValue;
myContiner.type //allow access to anything or a specific class type.
}
Your form will need to expose all the properties the user needs to change via binding to this cass model.