CODEWITHSUNDEEP
angulartypescriptionic4
aleksejjj
aleksejjj

Reputation: 1565

Ionic pipe TypeError: Cannot read property 'toString' of undefined

I have an Ionic 4 news reader app. Property pubDate of class UutinenPage is asynchronously being assigned a value data.items[this.id].pubDate in uutinen.page.ts. The value should look something like 2019-02-19 04:02:00. I need to print out this string with toLocaleDateString() so that the result is 19.2.2019. I am getting the following error:

TypeError: Cannot read property 'toString' of undefined
at JulkaisuaikaPipe.push../src/app/julkaisuaika.pipe.ts.JulkaisuaikaPipe.transform (julkaisuaika.pipe.ts:10)

uutinen.page.html:

<ion-header>
  <ion-toolbar>
    <ion-title>Yle Uutiset</ion-title>
    <ion-buttons slot="start">
      <ion-button (click)="meneTakaisin()">
        <ion-icon slot="start" name="arrow-back"></ion-icon>
      </ion-button>
    </ion-buttons>
  </ion-toolbar>
</ion-header>

<ion-content padding>
  <h1>{{ uutinen?.title }}</h1>
  <p>{{ uutinen?.description }}</p>
  <p><b>{{ uutinen?.categories[0] }}</b> {{ pubDate | julkaisuaika }}</p>
  <img [src]="uutinen?.thumbnail">
  <div [innerHTML]="uutinen?.content"></div>
</ion-content>

uutinen.page.ts:

import { Pipe, PipeTransform } from '@angular/core';
import { uutissyote } from './uutissyote.interface';

@Pipe({
  name: 'julkaisuaika'
})
export class JulkaisuaikaPipe implements PipeTransform {

  transform(pubDate?: uutissyote): any {
    let pvm = new Date(pubDate.toString());
    return pvm.toLocaleDateString();
  }

}

julkaisuaika.pipe.ts:

import { Pipe, PipeTransform } from '@angular/core';
import { uutissyote } from './uutissyote.interface';

@Pipe({
  name: 'julkaisuaika'
})
export class JulkaisuaikaPipe implements PipeTransform {

  transform(pubDate?: uutissyote): any {
    let pvm = new Date(pubDate.toString());
    return pvm.toLocaleDateString();
  }

}

Upvotes: 0

Views: 690

Answers (1)

Sajeetharan
Sajeetharan

Reputation: 222722

This could happen if the pubDate is null , you should add a null check before converting it to string,

 if(pubDate){
   let pvm = new Date(pubDate.toString());

Upvotes: 2

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