Mat date picker custom value in Angular getting error

Question

I am working on Mat date picker custom value. Here is my code which I am trying

      <div class="form-group" *ngIf="selectVal.value == 'Date'">
                <mat-form-field>
                <input matInput [matDatepicker]="picker" (dateChange)="formatDate(dateValue.value)" #dateValue  formControlName="assumptionValueInDatetime" class="form-control" placeholder="Choose a date" >
                    <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
                    <mat-datepicker #picker></mat-datepicker>
                </mat-form-field>
            </div>

Here is my ts code. Here is the format I want 07-JUL-2020

    formatDate(value) {
        const months = ['JAN','FEB','MAR','APR','MAY','JUN','JUL','AUG', 'SEP', 'OCT', 'NOV', 'DEC'];
        let formatDate = ('0' + value.getDate()).slice(-2) + "-" + months[value.getMonth()] + "-" + (value.getFullYear());
        return formatDate;
    }

This is what my payload looks like:

    initassumpationForm() {
        this.assumptionDesignForm = this.fb.group({
            assumptionValueInDatetime: this.formatDate(this.assumptionValueInDatetime)
        });     
    }

Getting error as:

ERROR TypeError: Cannot read property 'getDate' of undefined

@Chellappanவ if i use this format how that will convert in to 12-JUN-2020 any idea — Mr.M, Mar 08 '20 at 09:21
Have you checked this: https://material.angular.io/components/datepicker/overview#choosing-a-date-implementation-and-date-format-settings — Chellappan வ, Mar 08 '20 at 09:28

julianobrasil · Answer 1 · 2020-03-26T09:46:05.153

The best way you can do it is by building a custom date adapter (it's a service). As you're using JavaScript Date object as your underlying date format, you can just extend the NativeDateAdapter provided in @angular/material/core and override two methods: parse and format. The former gets a Date object out of your string format (eg.: 01-MAR-2020), and the latter gets a string object out of a Date object (like your formatDate function, provided in the question text, does).

After building your custom native date adapter class, just provide it in your AppModule using the token DateAdapter:

import {DateAdapter} from '@angular/material/core';
...

@NgModule({
  ...
  providers: [{provide: DateAdapter, useClass: CustomNativeDateAdapter}]
  ...
})
export class AppModule {}

Concerning the CustomNativeDateAdapter class, in your case it'll be something like:

import { Injectable } from '@angular/core';
import { NativeDateAdapter } from '@angular/material/core';

@Injectable()
export class CustomNativeDateAdapter extends NativeDateAdapter {
  months: string[] = [ 'JAN', 'FEB', 'MAR', 'APR',  'MAY', 
    'JUN', 'JUL', 'AUG', 'SEP', 'OCT', 'NOV', 'DEC' ];

  monthsObj: { [key: string]: number } = { JAN: 0, FEB: 1, MAR: 2, APR: 3, 
    MAY: 4, JUN: 5, JUL: 6, AUG: 7, SEP: 8, OCT: 9, NOV: 10, DEC: 11 };

  parse(value: any): Date | null {
    if (typeof value == 'number') {
      return new Date(value);
    }

    const dateRegex: RegExp = /^(0|1)[1-9]-[A-Z]{3}-(1|2)[0-9]{3}$/;
    if (typeof value == 'string' && dateRegex.test(value)) {
      const dateSplit = value.split('-');
      return new Date(+dateSplit[2], this.monthsObj[dateSplit[1]],
        +dateSplit[0], 12, 0, 0, 0);
    }

    return null;
  }

  format(date: Date, displayFormat: Object): string {
    if (!this.isValid(date)) {
      throw Error('NativeDateAdapter: Cannot format invalid date.');
    }

    let formatDate = ('0' + date.getDate()).slice(-2) +
      '-' + this.months[date.getMonth()] + '-' + date.getFullYear();
    return formatDate;
  }
}

Mat date picker custom value in Angular getting error

1 Answers1