Set undefined value using *ngIf and ngModelChange

Question

I am using (ngModelChange) with several attribute but one of its attribute can be null for some entry. For now the only solution I have found is to duplicate the input with *ngIf condition to check if attribute is not null.

<input *ngIf="!member.instrument" [(ngModel)]="member.firstname" (ngModelChange)="updateField(member.key,noinstrument,member.firstname)">
<input *ngIf="member.instrument"[(ngModel)]="member.firstname" (ngModelChange)="updateField(member.key,member.instrument.key,member.firstname)">

If I don't do this I have the following error calling the ngModelChange :

ERROR TypeError: Cannot read property 'member.instrument.key' of undefined

I'm sure there is a way to do this with only one input field... Maybe setting the member.instrument.key to null when it's not defined?

`updateField` method is using members from your typescript instance, and can be moved inside the method. If you're using an ngFor then you'll just want to pass in the index to the method. — Z. Bagley, Oct 27 '17 at 14:10

score 2 · Accepted Answer · answered Oct 27 '17 at 14:19

2

Try something like this

updateField(member.key,
            member.instrument?member.instrument.key:undefined,
            member.firstname)"

answered Oct 27 '17 at 14:19

Juli3n

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Set undefined value using *ngIf and ngModelChange

1 Answers1