Verifying currency in mat-input field

Question

Verifying currency in mat-input field

I need help implementing validation for inputting prices on a form. For example, if a user types in $20.0000, I want a validation message to appear marking the input as invalid. Would this type of validation require regex, and if so, how would I go about implementing it? I am unsure of the steps needed to achieve this and would greatly appreciate any guidance or potential solutions.

<mat-form-field appearance="legacy" floatLabel="always">
          <mat-label>Breakfast</mat-label>
          <input
            matInput
            type="number"
            class="example-right-align"
            placeholder="0"
            [formControl]="bfastamountCtrl"
            [value]="bfastamountCtrl.value | number: '1.2-2'"
          />
          <span matPrefix>$&nbsp;</span>
        </mat-form-field>

angular typescript

Answer 1

Answer №1

Are you working with Angular and a reactive form? If that's the case, you have two options:

a. Create a custom Validator for the specific field.

b. Use the pattern-validator.

Here's an example for option a:

const myValidator(control: FormControl) { 
    const value = control.value; 
    if (/* check for invalid value*/) { 
        return /* error object */
    }
    return null;
}

You can use it like this:

...
bfastamountCtrl = 
    new FormControl('', [myValidator]
);

And here's an example for option b:

...
bfastamountCtrl = 
    new FormControl('', [Validators.pattern("/' your regex-pattern */")
]);
...

Answer 2

Are you working with Angular and a reactive form? If that's the case, you have two options:

a. Create a custom Validator for the specific field.

b. Use the pattern-validator.

Here's an example for option a:

const myValidator(control: FormControl) { 
    const value = control.value; 
    if (/* check for invalid value*/) { 
        return /* error object */
    }
    return null;
}

You can use it like this:

...
bfastamountCtrl = 
    new FormControl('', [myValidator]
);

And here's an example for option b:

...
bfastamountCtrl = 
    new FormControl('', [Validators.pattern("/' your regex-pattern */")
]);
...

Answer 3

Answer №2

One way to enhance your form validation is by utilizing the pattern attribute for input controls.

<mat-form-field appearance="legacy" floatLabel="always">
      <mat-label>Lunch</mat-label>
      <input
        matInput
        type="text"
        class="example-center-align"
        pattern="^[a-zA-Z]+$"
        placeholder="Enter lunch item"
        [formControl]="lunchCtrl"
      />
    </mat-form-field>

Answer 4

One way to enhance your form validation is by utilizing the pattern attribute for input controls.

<mat-form-field appearance="legacy" floatLabel="always">
      <mat-label>Lunch</mat-label>
      <input
        matInput
        type="text"
        class="example-center-align"
        pattern="^[a-zA-Z]+$"
        placeholder="Enter lunch item"
        [formControl]="lunchCtrl"
      />
    </mat-form-field>

Verifying currency in mat-input field

Answer №1

Answer №2

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