Aurelia refresh property dependencies - aurelia

Question

Validate if checkbox should be displayed in html page:
get canPerformCommand() {
let r = false;
let valids = ['Success', 'Error'];
if (this.requests.length == 0) return false;
if (valids.indexOf(this.myresult[0].requestStatus) > 0) {
r = true;
}
return r;
}
Html page:
<span if.bind="canPerformCommand" class="panel-heading-buttons">
<button click.trigger="confirm()">Confirm</button>
</span>
Search:
return this.myService.getRequests()
.then(data => {
this.requests = data
//Somehow refresh canPerformCommand here?
});
this.requests will be empty on first page load, resulting in canPerformCommand = false.
I want to refresh canPerformCommand when using the search function.
Currently canPerformCommand will not refresh itself after a search has been done.
How do I refresh canPerformCommand after search using Property Dependencies?

Answer 1

Solution:
The easiest and most logical solution would be to change canPerformCommand into two separate entities -- a flag variable and a function. Make the flag variable be canPerformCommand and keep the if.bind=canPerformCommand but change the name of your function to updateCanPerformCommand() so that you can easily call this function from your return this.myService.getRequests() .then function.
Details:
Set up your view-model like this:
export class App { // <-- (or whatever yours is called)
canPerformCommnad = false;
constructor() {
// ...
}
updateCanPerformCommand() {
let r = false;
let valids = ['Success', 'Error'];
if (this.requests.length == 0) {
this.canPerformCommand = false;
} else if (valids.indexOf(this.myresult[0].requestStatus) > 0) {
this.canPerformCommand = true;
}
}
}

Answer 2

I believe you need to change myresult to requests in the canPerformCommand getter:
get canPerformCommand() {
let r = false;
let valids = ['Success', 'Error'];
if (this.requests.length == 0) return false;
if (valids.indexOf(this.requests[0].requestStatus) > 0) {
r = true;
}
return r;
}
Since this getter will be dirty checked by Aurelia, it will be called every 200ms. To avoid that, you can add a computedFrom decorator:
import {computedFrom} from 'aurelia-framework';
export class MyClass {
....
#computedFrom('requests')
get canPerformCommand() { ....

Answer 3

I replaced:
if (valids.indexOf(this.myresult[0].requestStatus) > 0) {
r = true;
}
With
if (valids.includes(this.requests[0].requestStatus)) {
r = true;
}
And now it works. I was using the indexOf function on other pages aswell, and strangely enough it worked on most of them. Must have been something wrong in my model.
Also, I agree that it would be better to use computedFrom.