Feeling lost with the syntax provided below:
constructor(controls: {[key: string]: AbstractControl}, optionals?: {[key: string]: boolean}, validator?: ValidatorFn, asyncValidator?: AsyncValidatorFn)
I'm curious about the type of the controls (first parameter). Is it a data structure that consists of key-value pairs where the key is a string and the value is an AbstractControl? Thank you!
Aha, just as you suspected, it is indeed a JavaScript object where the keys are strings and the values are instances of AbstractControl.
Here's an example:
{
"control1": new Control(),
"control2": new Control()
}
To define a variable of this type, you have two options:
let controls: { [key: string]: AbstractControl };
or
interface ControlsMap {
[key: string]: AbstractControl;
}
let controls: ControlsMap;
or perhaps even more elegantly:
interface ControlsMap<T extends AbstractControl> {
[key: string]: T;
}
let controls1: ControlsMap<AbstractControl>;
let controls2: ControlsMap<MyControl>;
Another option to consider in addition to the previous solution is utilizing the Record<Keys,Type> utility type for handling this scenario.
type DataMap = Record<string, AbstractDataStructure>;
const dataMapping: DataMap = {
keyX: new Structure(),
keyY: new Structure(),
};
An alternative approach using generics:
type DataMap<D extends AbstractDataStructure> = Record<string, D>;
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