carbon/build/static/store/SubscribeValue.js

47 lines
762 B
JavaScript

import {Subscribable} from "./Subscribable.js"
class SubscribeValue extends Subscribable {
constructor() {
super()
this.hasData = false
this.data = null
}
exists() {
return this.hasData
}
value() {
if (this.hasData) return this.data
else return null
}
set(data) {
const exists = this.exists()
this.data = data
this.hasData = true
if (exists) {
this.broadcast("editSelf", this.data)
} else {
this.broadcast("addSelf", this.data)
}
return this
}
edit(f) {
if (this.exists()) {
f(this.data)
this.set(this.data)
} else {
throw new Error("Tried to edit a SubscribeValue that had no value")
}
}
delete() {
this.hasData = false
this.broadcast("removeSelf")
return this
}
}
export {SubscribeValue}