feat(value-accessors): move the value accessors into @ionic/angular

packages/angular/src/directives/ion-select-value-accessor.ts

@@ -0,0 +1,41 @@
+import { Directive, ElementRef, HostListener, Renderer2 } from '@angular/core';
+import { ControlValueAccessor, NG_VALUE_ACCESSOR } from '@angular/forms';
+
+// NOTE: May need to look at this to see if we need anything else:
+// https://github.com/angular/angular/blob/5.0.2/packages/forms/src/directives/select_control_value_accessor.ts#L28-L158
+@Directive({
+  /* tslint:disable-next-line:directive-selector */
+  selector: 'ion-select, ion-radio-group, ion-segment, ion-datetime',
+  providers: [{ provide: NG_VALUE_ACCESSOR, useExisting: IonSelectValueAccessor, multi: true }]
+})
+export class IonSelectValueAccessor implements ControlValueAccessor {
+  constructor(private element: ElementRef, private renderer: Renderer2) {
+    this.onChange = () => {};
+    this.onTouched = () => {};
+  }
+
+  onChange: (value: any) => void;
+  onTouched: () => void;
+
+  writeValue(value: any) {
+    this.renderer.setProperty(this.element.nativeElement, 'value', value);
+  }
+
+  @HostListener('ionChange', ['$event.target.value'])
+  _handleChangeEvent(value: any) {
+    this.onChange(value);
+  }
+
+  @HostListener('ionBlur')
+  _handleBlurEvent() {
+    this.onTouched();
+  }
+
+  registerOnChange(fn: (value: any) => void) {
+    this.onChange = fn;
+  }
+
+  registerOnTouched(fn: () => void) {
+    this.onTouched = fn;
+  }
+}