Drew13 Drew13 - 21 days ago 14
TypeScript Question

Angular2 manually implement change detection using ApplicationRef

Getting a change detection error


Expression has changed after it was checked. Previous value: 'true'. Current value: 'false'


so I want to manually run another round of change detection. Found information about using
ApplicationRef.tick()
but currently getting error


ERROR in [default] C:\development\SolarUI11\src\app\update\update.component.ts:8
:11
Argument of type '{ selector: string; styles: any[]; template: any; providers: (
typeof ApplicationRef | typeof Date...' is not assignable to parameter of type '
Component'.
Types of property 'providers' are incompatible.
Type '(typeof ApplicationRef | typeof DatePipe)[]' is not assignable to type
'Provider[]'.
Type 'typeof ApplicationRef | typeof DatePipe' is not assignable to type '
Provider'.
Type 'typeof ApplicationRef' is not assignable to type 'Provider'.
Type 'typeof ApplicationRef' is not assignable to type 'FactoryProvide
r'.
Property 'provide' is missing in type 'typeof ApplicationRef'.`


I think I'm just stuck on the syntax of implementing this, couldn't find enough information myself to be able to use it.

Typescript:

import { Component, Input, ApplicationRef } from '@angular/core';
import { FormGroup, FormBuilder, Validators } from '@angular/forms';
import {NgbDateStruct} from '@ng-bootstrap/ng-bootstrap';
import {DatePipe} from "@angular/common";
import { DataTable } from '../data/datatable';
import { DPS } from '../data/datainfo.ts';

@Component({
selector: 'update-validation',
styleUrls: ['../app.component.css'],
templateUrl: 'update.component.html',
providers: [DatePipe, ApplicationRef]
})
export class UpdateComponent {
@Input() receivedRow:DataTable;
public dt: NgbDateStruct;
public dt2: NgbDateStruct;
public startCheck: boolean = false;
public endCheck: boolean = false;
updateForm : FormGroup;

constructor(fb: FormBuilder, private datePipe: DatePipe, private appref: ApplicationRef){
this.updateForm = fb.group({
'dataPoint' : [null, Validators.required],
'ICCP' : [null, Validators.required],
'startDate' : [null, Validators.required],
'endDate' : [null, Validators.required]
}, {validator: this.endDateAfterOrEqualValidator})
}

ngOnChanges(){
if(this.receivedRow){
this.updateForm.controls['dataPoint'].setValue(this.receivedRow.tDataPoint);
this.updateForm.controls['ICCP'].setValue(this.receivedRow.tICCP);
this.updateForm.controls['startDate'].setValue(this.receivedRow.tStartDate);
this.updateForm.controls['endDate'].setValue(this.receivedRow.tEndDate);
}
}

resetForm(){
location.reload();
//this.updateForm.reset();
}

submitForm(value: any, originalRow: any){
var dataPointID = originalRow.receivedRow.tDataPoint;
for (let entry in DPS) {
if (DPS[entry].tDataPoint === dataPointID) {
DPS[entry].tDataPoint = String((<HTMLInputElement>document.getElementById("dataPoint")).value);
DPS[entry].tICCP = String((<HTMLInputElement>document.getElementById("ICCP")).value);
DPS[entry].tStartDate = String((<HTMLInputElement>document.getElementById("startDate")).value);
DPS[entry].tEndDate = String((<HTMLInputElement>document.getElementById("endDate")).value);
}
}
}

getStartDate(){
var month = this.receivedRow.tStartDate.substring(0,2);
var day = this.receivedRow.tStartDate.substring(3,5);
var year = this.receivedRow.tStartDate.substring(6,10);
var dateToUse = new Date(Number(year),Number(month)-1,Number(day));
let timestamp = this['startDate'] != null ? new Date(this['startDate'].year, this['startDate'].month-1, this['startDate'].day).getTime() : dateToUse.getTime();
this.updateForm.controls['startDate'].setValue(this.datePipe.transform(timestamp, 'MM/dd/yyyy'));
this.appref.tick();
}

getEndDate(){
var month = this.receivedRow.tEndDate.substring(0,2);
var day = this.receivedRow.tEndDate.substring(3,5);
var year = this.receivedRow.tEndDate.substring(6,10);
var dateToUse = new Date(Number(year),Number(month)-1,Number(day));
let timestamp = this['endDate'] != null ? new Date(this['endDate'].year, this['endDate'].month-1, this['endDate'].day).getTime() : dateToUse.getTime();
this.updateForm.controls['endDate'].setValue(this.datePipe.transform(timestamp, 'MM/dd/yyyy'));
this.appref.tick();
}

public showDatePick(selector):void {
if(selector === 0) {
this.startCheck = !this.startCheck
} else {
this.endCheck = !this.endCheck;
}
}

endDateAfterOrEqualValidator(formGroup): any {
var startDateTimestamp, endDateTimestamp;
for(var controlName in formGroup.controls) {
if (controlName.indexOf("startDate") !== -1) {
startDateTimestamp = Date.parse(formGroup.controls[controlName].value);
}
if (controlName.indexOf("endDate") !== -1) {
endDateTimestamp = Date.parse(formGroup.controls[controlName].value);
}
}
return (endDateTimestamp < startDateTimestamp) ? { endDateLessThanStartDate: true } : null;
}
}

Answer

Inject

constructor(private cdRef:ChangeDetectorRef) {}

and use it

ngOnChanges(){
if(this.receivedRow){
  this.updateForm.controls['dataPoint'].setValue(this.receivedRow.tDataPoint);
  this.updateForm.controls['ICCP'].setValue(this.receivedRow.tICCP);
  this.updateForm.controls['startDate'].setValue(this.receivedRow.tStartDate);
  this.updateForm.controls['endDate'].setValue(this.receivedRow.tEndDate);
  this.cdRef.detectChanges();
  }
}

This should fix the first error message.