CODEWITHSUNDEEP
angularcustom-validators
lordkain
lordkain

Reputation: 3109

custom validation acces form components

I want to make a custom validation for angular2. This validation must access another component of the form. Is this possible?

My template

<input type="tekst" id="startDate" name="startDate" [(ngModel)]="model.startDate" #startDate="ngModel" >

<input type="tekst" id="endDate" name="endDate" [(ngModel)]="model.endDate" #endDate="ngModel" customValidator>

My validator

...
@Directive({
    selector: '[customValidator][ngModel][customValidator][formControl]',
    providers: [
        provide : NG_VALIDATORS,
        useExisting : forwardRef(() = > CustomValidator),
        Multi : true
    }]
})

export class CustomValidator impelments Validator {
    constructor(){}

    validate(c : FormControl) : {[key : string] : any} {

        // HOW TO ACCESS startDate CONTROL HERE? OR ITS VALUE? OR THE MODEL
    }

Upvotes: 4

Views: 816

Answers (2)

Robert
Robert

Reputation: 3483

You can like

@Directive({
    selector: '[customValidator][ngModel][customValidator][formControl]',
    providers: [
        provide : NG_VALIDATORS,
        useExisting : forwardRef(() = > CustomValidator),
        Multi : true
    }]
})

export class CustomValidator impelments Validator {
    constructor(){}

    validate(c : FormControl) : {[key : string] : any} {
         let control_value= c.value;
        // HOW TO ACCESS startDate CONTROL HERE? OR ITS VALUE? OR THE MODEL
    }

also refer this link also: custom validator and custom validtor with reverse match

Upvotes: 0

Tomasz Kula
Tomasz Kula

Reputation: 16837

If you want to implement cross validation you should move the validation to the ancestor control.

Then your validate method can look like this:

validate(fg: FormGroup) {
  const start = fg.get('startDate').value;
  const end = fg.get('enDate').value;

  return start !== null && end !== null && start < end 
   ? null 
   : { range: true };
};

Read more about cross validation here.

Upvotes: 1

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