Form validation with template attributes in Angular - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of template-driven form validation in Angular?

Template-driven form validation lets you add simple validation rules directly in your HTML templates using attributes. It helps check user input before sending data.

beginner

How do you mark an input field as required using template attributes in Angular?

Add the required attribute to the input element. Angular will check if the user has entered a value and mark the field invalid if empty.

beginner

What does the ngModel directive do in template-driven forms?

ngModel binds the input field to a variable in your component and tracks its value and validation status automatically.

intermediate

How can you check if a form control is valid or invalid in the template?

Use the template reference variable with #name="ngModel" and check name.valid or name.invalid to show messages or styles.

beginner

What attribute helps validate the minimum length of an input in Angular template forms?

The minlength attribute sets the minimum number of characters required. Angular marks the field invalid if the input is shorter.

Which attribute makes an input field mandatory in Angular template-driven forms?

A readonly

B minlength

C required

D pattern

The 'required' attribute ensures the user must enter a value for the field to be valid.

What directive binds input data to the component in template-driven forms?

A ngModel

B ngClass

C ngIf

D ngFor

ngModel connects the input field to the component variable and tracks changes.

How do you access the validity state of an input in the template?

A Using a service

B Using a template reference variable with ngModel

C Using a pipe

D Using a component method

A template reference variable like #field="ngModel" lets you check field.valid or field.invalid.

Which attribute validates the minimum number of characters in an input?

A maxlength

B required

C pattern

D minlength

minlength sets the minimum length required for the input value.

What happens if a required input field is left empty in a template-driven form?

A The form control is invalid

B The form control is valid

C The form submits anyway

D Angular ignores the field

If a required field is empty, Angular marks it as invalid and prevents form submission if validation is checked.

Explain how to add and check validation for a required input field using Angular template attributes.

Think about how HTML attributes and Angular directives work together in the template.

Describe how Angular template-driven forms track and show validation status to users.

Focus on the flow from user input to validation feedback in the template.