Based on selection of card type conditional validation is applied
{{userFormGroup.controls.cardType.errors.creditCard.message}}
If you want to apply conditional validation on 'Visa Card' then you need to add 'card type' input as 'Visa'.
It shows custom message
Conditional Expression with type 'string'
{{userFormGroup.controls.otherVisaCard.errors.creditCard.message}}
If you want to apply conditional validation on 'American Express' then you need to add 'card type' input as 'AmericanExpress'.
Message comes from Reactive Form Config
{{userFormGroup.controls.americanExpressCard.errors.creditCard.message}}
If you want to apply conditional validation on 'MaestroCard Card' then you need to add 'card type' input as 'Maestro'.
{{userFormGroup.controls.maestroCard.errors.creditCard.message}}
If you want to apply conditional validation on 'JCB Card' then you need to add 'card type' input as 'JCB'.
{{userFormGroup.controls.jcbCard.errors.creditCard.message}}
If you want to apply conditional validation on 'Discover Card' then you need to add 'card type' input as 'Discover'.
{{userFormGroup.controls.discoverCard.errors.creditCard.message}}
If you want to apply conditional validation on 'Master Card' then you need to add 'card type' input as 'MasterCard'.
{{userFormGroup.controls.masterCard.errors.creditCard.message}}
If you want to apply conditional validation on 'Diners Club Card' then you need to add 'card type' input as 'DinersClub'.
{{userFormGroup.controls.dinersClubCard.errors.creditCard.message}}
If you want to apply conditional validation on 'Visa Card' then you need to add 'card type' input as 'Visa'.
It shows custom message
Conditional Expression with type 'function'
{{userFormGroup.controls.visaCard.errors.creditCard.message}}