Handling Forms

vee-validate makes it easy to handle form submissions, resets, and DX to make your forms much easier to reason about and less of a burden to maintain. The useForm function allows you to easily handle:

Form Metadata

Forms have a meta object value containing useful information about the form, it acts as an aggregation of the metadata for the fields inside that form.

jsconst { meta } = useForm();

meta.value.dirty;
meta.value.pending;
meta.value.touched;
meta.value.valid;
meta.value.initialValues;

• valid: The form’s validity status, will be true if the errors array is empty initially, but will be updated once the form is mounted.
• touched: If at least one field was blurred (unfocused) inside the form.
• dirty: If at least one field’s value was updated.
• pending: If at least one field’s validation is still pending.
• initialValues: All fields’ initial values, this is an object where the keys are the field names.

Here is a simple example where we disable the form’s submit button unless a field was touched.

Handling Submissions

vee-validate exposes useful defaults to help you handle form submissions whether you submit them using JavaScript or native HTML submissions.

JavaScript Submissions (AJAX)

To handle submissions, you can use the handleSubmit function to create submission handlers for your forms, the handleSubmit function accepts a callback that receives the final form values.

jsconst { handleSubmit } = useForm({
  validationSchema: yup.object({
    email: yup.string().email().required(),
    password: yup.string().min(6).required(),
  }),
});

// Creates a submission handler
// It validates all fields and doesn't call your function unless all fields are valid
// You can bind `onSubmit` to a form element's submit event, or call it directly to submit the current data.
const onSubmit = handleSubmit(values => {
  alert(JSON.stringify(values, null, 2));
});

Here is an example that makes use of handleSubmit to validate before submitting the form.

The handleSubmit function will only execute your callback once the returned function (onSubmit in the example) if all fields are valid, meaning you don’t have to handle if the form is invalid in your logic.

You can call the returned function either manually or via an event like @submit and it will validate all the fields and execute the callback if everything passes validation.

As a bonus, when the returned function is used as an event handler (like in the previous example) it will automatically prevent the default submission of the form so you don’t need to use the prevent modifier like you normally would.

Full-Page Submissions (non-AJAX)

For non-ajax submissions that trigger a full page reload, you can use the submitForm function instead of handleSubmit. You normally would use this if you are not building a single-page application. In the following example, we submit the form to another tab using the get form method.

In that case YOU MUST use submitForm as an event handler for the submit event for a native form element, otherwise, it would have no effect.

Handling Invalid Submissions

Sometimes you want to perform some logic after a form fails to submit due to validation errors (e.g. focusing the first invalid field), you can pass a callback as the second argument to the handleSubmit function.

jsconst { handleSubmit } = useForm();

function onSuccess(values) {
  alert(JSON.stringify(values, null, 2));
}

function onInvalidSubmit({ values, errors, results }) {
  console.log(values); // current form values
  console.log(errors); // a map of field names and their first error message
  console.log(results); // a detailed map of field names and their validation results
}

// This handles both valid and invalid submissions
const onSubmit = handleSubmit(onSuccess, onInvalidSubmit);

Here is a quick example of how to scroll to and focus the first invalid field after a failed submission attempt.

Submission Progress

Quite often you need to show your users a submission indicator, or you might want to disable the submit button entirely until the submission attempt is done. The useForm function exposes an isSubmitting ref that you can use.

The isSubmitting state will be set to true once the validation of the form starts (as a result of a submit event) and will keep track of the submission handler you passed to either onSubmit or until it calls submitForm. If the submission handler throws any errors or completes successfully it will be set to false afterward.

jsconst { isSubmitting } = useForm();

Submit Count

The useForm function also exposes a submitCount ref that you can use to track the number of submissions attempted by the user. The count is incremented regardless of the validation result.

jsconst { submitCount } = useForm();

Maybe you want to lock the form if too many attempts were made, or you want to show a message after the first submission attempt.

Submission Behavior

vee-validate does the following when calling submission handlers created by handleSubmit or when calling submitForm as a result of the user submitting the form.

Before validation stage

• Sets all fields touched meta to true
• Sets isSubmitting form state to true
• Increments the submitCount form state by 1

Validation stage

• Sets form and individual fields meta pending to true to indicate validation is in progress
• Runs the validation function/schema/rule against the current form values asynchronously
• Checks for any errors in the validation result
  • If there are errors then it will skip the next stage and update the validation state (meta, errors) for the form and fields
  • If there aren’t any errors then it will set the pending meta flag to false and proceed to the next stage

After validation stage

• Calls the handleSubmit handler you passed
• After the callback finishes (it will wait if the result is asynchronous), then it will set isSubmitting to false

Note that there isn’t a need to have isSubmitting set back to false if you’ve used submitForm, as this submission method will perform a full-page refresh (native forms behavior).

Form Values

You may have noticed in the earlier examples that you can access all fields’ values using the values reactive object returned by useForm.

jsconst { values } = useForm();

The values object is read-only and should not be mutated with a v-model or by assigning a value to it. This is because all mutations are done through the vee-validate API, this is because mutations to form state need to have a context.

For example:

jsconst { values } = useForm();

// ❌ Do not do that!
values.email = '';

In order for the form UX to be stable, we need to understand why the email value was set to ''. Was it being reset? should we run validation again? This is the type of small differences that are a result of vee-validate’s design choice based on fields and forms, not values.

Initial Values

Since you don’t have to use v-model to track your values, the useForm function allows you to define the starting values for your fields, by default all fields start with undefined as a value.

Using the initialValues option you can send an object that contains the field names as keys and their values:

jsconst { defineInputBinds } = useForm({
  initialValues: {
    email: 'test@example.com',
    password: 'p@$$w0rd',
  },
});

You can reset initial values at any time using the resetForm function returned by useForm.

Manually Setting Form Values

You can set any field’s value using either setFieldValue or setValues returned by useForm.

jsconst { setFieldValue, setValues } = useForm();

// Sets a value of a specific field in the form values
setFieldValue('fieldName', 'value');

// Merges the given object with the current form values
setValues({
  fieldName: 'value',
});

Controlled Values

The form values can be categorized into two categories:

• Controlled values: values that have a form input controlling them via defineInputBinds or defineComponentBinds or useField or <Field />.
• Uncontrolled values: values that are inserted dynamically with setFieldValue or inserted initially with initial values.

Sometimes you maybe only interested in controlled values. For example, your initial data contains noisy extra properties from your API and you wish to ignore them when submitting them back to your API.

When accessing values from useForm result or the submission handler you get all the values, both controlled and uncontrolled values. To get access to only the controlled values you can use controlledValues from the useForm result:

jsconst { handleSubmit, controlledValues } = useForm();

const onSubmit = handleSubmit(async () => {
  // Send only controlled values to the API
  const response = await client.post('/users/', controlledValues.value);
});

Alternatively, for less verbosity, you can create submission handlers with only the controlled values with handleSubmit.withControlled which has the same API as handleSubmit:

jsconst { handleSubmit } = useForm();

const onSubmit = handleSubmit.withControlled(async values => {
  // Send only controlled values to the API
  const response = await client.post('/users/', values);
});

Here is an example that filters out some noisy initial values when submitting the form using the withControlled modifier.

Setting initial values asynchronously

Sometimes your data is fetched asynchronously from an API and you want to set the initial values or the current values after the data is fetched. You can do that by using resetForm to set both current and initial data.

You could alternatively use setValues but note that setValues can trigger validation and do not reset the meta state for the fields like dirty or touched.

Handling Resets

vee-validate also handles form resets in a similar way to submissions. When resetting the form, all fields’ errors will be cleared, meta info will be reset to defaults and the values will be reset to their original or initial values.

To reset forms you can use the resetForm function returned by useForm. You can also reset the form to a new state by passing a FormState object to the resetForm function. You can then set errors, touched meta, and the values.

jsconst { resetForm } = useForm();

// Rests the form
resetForm();

//
resetForm({
  touched: {
    email: false,
  },
  errors: {
    email: 'custom error',
  },
  values: {
    email: 'newvalue@email.com',
  },
});

This is the shape of the FormState object:

tsinterface FormState {
  // any error messages
  errors: Record<string, string>;
  // touched meta flags
  touched: Record<string, boolean>;
  // Form Values
  values: Record<string, any>;
}

Here is an example where a full form is being reset:

Resetting Forms After Submit

Usually, you will reset your forms after successful submission. For convenience, the onSubmit handler receives an additional FormActions object in the second argument that allows you to do some actions on the form after submissions, this is the shape of the FormActions object:

tsexport interface FormActions {
  setFieldValue: (field: T, value: any) => void;
  setFieldError: (field: string, message: string | undefined) => void;
  setErrors: (fields: Partial<Record<string, string | undefined>>) => void;
  setValues: (fields: Partial<Record<T, any>>) => void;
  setFieldTouched: (field: string, isTouched: boolean) => void;
  setTouched: (fields: Partial<Record<string, boolean>>) => void;
  resetForm: (state?: Partial<FormState>) => void;
}

This is an example of using the form actions object to reset the form:

Errors

As you have previously seen in some examples, you have access to errors with useForm that contains a mapping of each field’s path and its error message.

jsconst { errors } = useForm();

However, if you want to display multiple errors for your fields then you can use errorBag which is a mapping of each field’s path and an array of error messages for that field.

jsconst { errorBag } = useForm();

Here is an example that displays multiple errors for a field:

Initial Errors

If you are building a non-SPA application it is very common to pre-fill form errors using server-side rendering, frameworks like Laravel and Rails make this very easy to do. vee-validate supports filling the errors initially before any validation is done using the initialErrors option.

The initialErrors option accepts an object containing the field names as keys with their corresponding error message string.

jsuseForm({
  initialErrors: {
    email: 'This email is already taken',
    password: 'The password is too short',
  },
});

Setting Errors Manually

Quite often you will find yourself unable to replicate some validation rules on the client-side due to natural limitations. For example, unique email validation is complex to implement on the client side. So the ability to set errors manually can be useful.

You can set messages for fields by using either setFieldError which sets an error message for one field at a time, or by using the setErrors function which allows you to set error messages for multiple fields at once.

Both functions are available as a return value from useForm. In the following example, we check if the server response contains any validation errors and we set them on the fields:

jsconst { handleSubmit, setFieldError, setErrors } = useForm();

const onSubmit = handleSubmit(async values => {
  // Send data to the API
  const response = await client.post('/users/', values);

  // all good
  if (!response.errors) {
    return;
  }

  // set single field error
  if (response.errors.email) {
    setFieldError('email', response.errors.email);
  }

  // set multiple errors, assuming the keys are the names of the fields
  // and the key's value is the error message
  setErrors(response.errors);
});

Alternatively, you can use the FormActions passed as the second argument to the handleSubmit callback which contains both functions for convenience:

jsconst onSubmit = handleSubmit(async (values, actions) => {
  // Send data to the API
  const response = await client.post('/users/', values);
  // ...

  // set single field error
  if (response.errors.email) {
    actions.setFieldError('email', response.errors.email);
  }

  // set multiple errors, assuming the keys are the names of the fields
  // and the values is the error message
  actions.setErrors(response.errors);
});

Here is an example that sets form errors after submission, usually you will have a backend API that returns the errors: