After exploring options with knockout-decorators and knockout-es5, I have come to the conclusion that using any as the type for widget options would be the simplest solution for your issue.
The template for both approaches remains the same:
<div data-bind="dxButton: buttonOptions"></div>
Using knockout-es5
This method involves creating a computed property separately, which may lead to loss of some strong typing benefits due to lack of well-typed creation process.
// Import necessary modules from DevExtreme.
import "devextreme/ui/button";
import DevExpress from "devextreme/bundles/dx.all";
import * as ko from "knockout";
// Import knockout-es5 for track and defineProperty functionality
import "knockout-es5";
// Util function to enhance compute creation using keyof
const createComputed = <T>(prototype: T, key: keyof T, computedFunc: Function): void => {
ko.defineProperty(prototype, key, computedFunc);
}
class DevextremeTestViewModel {
clickCounter: number = 0;
buttonOptions: DevExpress.ui.dxButtonOptions;
constructor() {
this.buttonOptions = {
text: "Start",
onClick: this.increaseCounter
};
// Make clickCounter observable
ko.track(this, ["clickCounter"]);
// Assign computed value to text property in widget options
createComputed(this.buttonOptions, "text", () => {
return `Clicked ${this.clickCounter} times`;
});
}
increaseCounter(): void {
this.clickCounter++;
}
}
Using knockout-decorators
This approach also requires creating a computed property separately within the viewModel. It involves a "hack" to copy the getter of the computed property to the widget options:
import "devextreme/ui/button";
import DevExpress from "devextreme/bundles/dx.all";
// Include required decorators
import { observable, computed } from "knockout-decorators";
// Function to copy getter from one property to another
const copyGetter = <T, TProp>(prototype: T, key: keyof T, propProto: TProp, propertyKey: keyof TProp) => {
let getter = Object.getOwnPropertyDescriptor(propProto, propertyKey).get;
Object.defineProperty(prototype, key, {
get: getter
});
}
class DevextremeTestViewModel {
// Create observable
@observable clickCounter: number = 0;
// Create computed based on observable
@computed({ pure: true }) get buttonText(): string {
return `Clicked ${this.clickCounter} times`;
};
buttonOptions: DevExpress.ui.dxButtonOptions;
constructor() {
this.buttonOptions = {
text: this.buttonText,
onClick: this.increaseCounter
};
// Copy getter from computed to options property
copyGetter(this.buttonOptions, "text", this, "buttonText");
}
increaseCounter(): void {
this.clickCounter++;
}
}
Using any
Given the limitations in changing the interface of widget's options, utilizing any seems like the cleanest way forward:
import "devextreme/ui/button";
import DevExpress from "devextreme/bundles/dx.all";
import { observable, computed } from "knockout-decorators";
import * as ko from "knockout";
class DevextremeTestViewModel {
// Create observable
@observable clickCounter: number = 0;
buttonOptions: any = {
text: ko.pureComputed(()=> {
return `Clicked ${this.clickCounter} times`;
}),
onClick: this.increaseCounter
};
increaseCounter(): void {
this.clickCounter++;
}
}