How to implement observable "bridge" in knockout.js?

@denis 

To implement an observable bridge in knockout.js, you can follow these steps:

1. Define an observable property in your view model that will act as the bridge between two other observables.
2. Subscribe to changes in the source observables and update the bridge property whenever either of them changes.
3. Use the ko.pureComputed function to create a computed observable that depends on the bridge property. This computed observable will automatically update whenever the bridge property changes.

Here's an example implementation:

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function ViewModel() {
  this.sourceObservable1 = ko.observable();
  this.sourceObservable2 = ko.observable();
  
  this.bridgeObservable = ko.observable();
  
  ko.computed(() => {
    const value1 = this.sourceObservable1();
    const value2 = this.sourceObservable2();
    
    this.bridgeObservable(value1 + ' ' + value2);
  });
}

In this example, whenever either sourceObservable1 or sourceObservable2 changes, the bridgeObservable will be updated with their combined value. You can then bind your UI elements to the bridgeObservable to reflect the changes in both source observables.