Class ValueObserver

src/core/value_observer.ts:6–130

import { capitalize } from "./string_helpers"

export class ValueObserver implements StringMapObserverDelegate {
  readonly context: Context
  readonly receiver: any
  private stringMapObserver: StringMapObserver
  private valueDescriptorMap: { [attributeName: string]: ValueDescriptor }

  constructor(context: Context, receiver: any) {
    this.context = context
    this.receiver = receiver
    this.stringMapObserver = new StringMapObserver(this.element, this)
    this.valueDescriptorMap = (this.controller as any).valueDescriptorMap
  }

  start() {
    this.stringMapObserver.start()
    this.invokeChangedCallbacksForDefaultValues()
  }

  stop() {
    this.stringMapObserver.stop()
  }

  get element() {
    return this.context.element
  }

  get controller() {
    return this.context.controller
  }

  // String map observer delegate

  getStringMapKeyForAttribute(attributeName: string) {
    if (attributeName in this.valueDescriptorMap) {
      return this.valueDescriptorMap[attributeName].name
    }
  }

  stringMapKeyAdded(key: string, attributeName: string) {
    const descriptor = this.valueDescriptorMap[attributeName]

    if (!this.hasValue(key)) {
      this.invokeChangedCallback(key, descriptor.writer(this.receiver[key]), descriptor.writer(descriptor.defaultValue))
    }
  }

  stringMapValueChanged(value: string, name: string, oldValue: string) {
    const descriptor = this.valueDescriptorNameMap[name]

    if (value === null) return

    if (oldValue === null) {
      oldValue = descriptor.writer(descriptor.defaultValue)
    }

    this.invokeChangedCallback(name, value, oldValue)
  }