Features

• Keeps form's state and validation results
• Supports any kind of validation functions
• Dirty checking
• Separates data from view
• Relies on hooks, but can easily be used with class components

Installation

Package can be installed with one of the following commands (depending on whether you prefer npm, yarn or pnpm)

npm install @enterwell/react-form-validation

yarn add @enterwell/react-form-validation

pnpm add @enterwell/react-form-validation

Usage

Two quick steps to validate any kind of input.

Step 1:

• Define custom validation (or use some of predefined) and use it to initialize validation hook

import { isValidEmail, useValidation } from '@enterwell/react-form-validation';

const email = useValidation('[email protected]', isValidEmail);

Step 2:

• Pass the email data to your input

<div>
    <input
        className={email.error ? 'error' : 'no-error'}
        {...email.props} // This is shorthand for passing the `value`, `onChange` and `onBlur` properties
    />
    {email.error && (
        <span className="error-message">Incorrect email!</span>
    )}
</div>

And thats all!

API

useValidation(initialValue, validationFn, config?)

Hook that keeps on form field's data.

Params

| Name | Type | Required | Description | | ---- | ---- | ---- | ----------- | | initialValue | any | yes | Field's initial value | | validationFn | (any) => boolean or Promise<boolean> | yes | Function for validating the field's value | | config | {   receiveEvent?: boolean,   reversed?: boolean   ignoreDirtiness?: boolean} | no | Additional hook configuration.receiveEvent inidicates whether onChange callback will receive whole event or just target's valuereversed indicates whether reversed error logic should be applied (error being false when present, instead of true)ignoreDirtiness indicating whether field's dirtiness should be ignored (by default, field is validate on blur, but only if field is dirty ie. if its value has been changed)|

Returns

| Type | Description | |---- | ----------- | | {   value: any,   error: boolean   onChange: (any, config?) => void   onBlur: (event, config?) => void   setValue: (value: any) => void   validate: (any, config?) => boolean or Promise<boolean>   reset: () => void,   props: {      value: any,      onChange: (any, config?) => void      onBlur: (event, config?) => void   }} | Object with field's data and callbacks.value - field's current valueerror - is error present flag (true if value was validated and didn't pass validation, false otherwise)onChange - callback for change event (changes the value and validates it if previous value wasn't correct)onBlur - callback for blur event (validates the value)setValue - function for setting the internal value (does not validate the input, enabling support for async data loading)validate - function for validating field's valuereset - function for resetting field's dataprops - set of props that can be spread on standard input elements (same as props in root object, just grouped for better DX)onChange, onBlur and validate functions accept config as last parameter - this will override config from useValidation if provided. |

Usage example

import { useValidation, isNonEmptyString } from '@enterwell/react-form-validation';

/* Some code... */

const userFormData = {
    name: useValidation(name, isNonEmptyString),
    age: useValidation(age, () => true)
};
console.log(userFormData.name) // {value: "Matej", error: false, onChange: ƒ, onBlur: ƒ, validate: ƒ, reset: f}"

extractValues(fields)

Util function for extracting values from fields' data objects.

Params

| Name | Type | Required | Description | | ---- | ---- | ---- | ----------- | | fields | {  key: { value: any },  ...} | yes | Form field's data (each field must have value property - other properties are not important) |

Returns

| Type | Description | |---- | ----------- | | Object | Object with fields' names as keys, and their values as values |

Usage example

import { ..., extractValues } from '@enterwell/react-form-validation';

/* useValidation example's code... */

const data = extractValues(userFormData);
//    ^ { name: "Matej", age: 10 }

setValues(fields, values)

Util function for setting field's values from provided data objects.

Params

| Name | Type | Required | Description | | ---- | ---- | ---- | ----------- | | fields | {  key: { value: any },  ...} | yes | Form field's data. | | values | {  key: any,  ...} | yes | Form field's values to be set to fields. |

Usage example

import { ..., setValues } from '@enterwell/react-form-validation';

const formData = {
    name: useValidation('', isNonEmptyString)
};

const item = useItem();
useEffect(() => {
    if (item) {
        setValues(formData, {
            name: item.name
        });
    }
}, [item]);

validateFields(fields)

Util function for validating values of all fields

Params

| Name | Type | Required | Description | | ---- | ---- | ---- | ----------- | | fields | {  key: {    value: any    validate: (any) => boolean  },  ...] | yes | Form field's data (each field must have value and validate properties - other properties are not important) |

Returns

| Type | Description | |---- | ----------- | | boolean or Promise<boolean> | false if form data is correct, true otherwise. Promise with same result when at least one validation function resolved to Promise. |

Usage example

import { ..., validateFields } from '@enterwell/react-form-validation';

/* useValidation example's code... */

const hasError = validateFields(userFormData);
console.log(hasError) // false

resetFields(fields)

Util function for resetting all fields' data.

Params

| Name | Type | Required | Description | | ---- | ---- | ---- | ----------- | | fields | {  key: { reset: () => void },  ...} | yes | Form field's data (each field must have reset property - other properties are not important) |

Usage example

import { ..., resetFields } from '@enterwell/react-form-validation';

/* useValidation example's code... */

resetFields(userFormData);

submitForm(fields, onSubmit)

Util function for handling the form submit. Form's fields are first validated. If all values are correct, they are extracted to data object and passed to onSubmit callback. Returns value of onSubmit callback.

Params

| Name | Type | Required | Description | | ---- | ---- | ---- | ----------- | | fields | {  key: {    value: any    validate: (any) => boolean  },  ...} | yes | Form field's data (each field must have value and validate properties - other properties are not important) | | onSubmit | (any) => object or void | yes | On submit callback |

Returns

| Type | Description | |---- | ----------- | | object or Promise<object> or undefined | Return value of onSubmit callback, wrapped in promise with same result when at least one validation function resolved to Promise. Returns undefined if validation fails or onSubmit is of return type void. |

Usage example

import { ..., submitForm } from '@enterwell/react-form-validation';

/* useValidation example's code... */

const onSubmit = (data) => fetch("www.some-url.com/post", {
    method: 'POST',
    data: JSON.stringify(data)
});
submitForm(userFormData, onSubmit);

cancelForm(fields, onCancel)

Util function for handling the form cancel. Form's fields are reset and onCancel callback is called.

Params

| Name | Type | Required | Description | | ---- | ---- | ---- | ----------- | | fields | {  key: { reset: () => void },  ...} | yes | Form field's data (each field must have reset property - other properties are not important) | | onCancel | (any) => void | yes | On cancel callback |

Usage example

import { ..., cancelForm } from '@enterwell/react-form-validation';

/* useValidation example's code... */

const onCancel = (data) => alert("Form has been reset");
cancelForm(userFormData, onCancel);

Unless otherwise stated, each validation function will have the following #### Params and #### Returns.

Params

| Name | Type | Required | Description | | ---- | ---- | ---- | ----------- | | value | any | no | Form field's value |

Returns

| Type | Description | |---- | ----------- | | boolean | true if field's value is correct, false otherwise |

noError()

No error validation. Value of the field with this validation function will always be correct.

areEqual(value, other)

Are values equal validation. Value of the field with this validation function will be correct if it is equal to some other value (e.g. some other field's value).

Params

| Name | Type | Required | Description | | ---- | ---- | ---- | ----------- | | value | any | no | Form field's value | | other | any | no | Some other value |

Returns

| Type | Description | |---- | ----------- | | boolean | true if field's value is correct, false otherwise |

isTrue(value)

Is true validation. Value of the field with this validation function will be correct only if it is true.

isNotNull(value)

Is not null validation. Value of the field with this validation function will be correct only if it is not null.

isNonEmptyString(value)

Is non-empty string validation. Value of the field with this validation function will be correct if it is not an empty string.

isValidNumber(value)

Is valid number validation. Value of the field with this validation function will be correct if it represents the valid number (as number or as string).

isPositiveNumber(value)

Is positive number validation. Value of the field with this validation function will be correct if it is the positive number.

isNegativeNumber(value)

Is negative number validation. Value of the field with this validation function will be correct if it is the negative number.

isNonEmptyArray(value)

Is non-empty array validation. Value of the field with this validation function will be correct if it is the non-empty array.

isValidEmail(value)

Is valid email validation. Value od the field with this validation function will be correct if it is non-empty string with valid email address.

isValidIpAddress(value)

Is valid IP address validation. Value od the field with this validation function will be correct if it is a non-empty string with valid IPv4 or IPv6 address.

Future plans

We noticed that there are few things which could be added to our package in order to make it more flexible and easy to use. Here is what you can expect in the future:

• additional config which will enable to change when value is validate (e.g. only in onChange, in onBlur but only if current value is not valid and so on)
• more validation functions