use-form-validator

Hook for form validation in React

Installation

npm add use-form-validator

Usage

API

import React, { useState, useCallback } from "rect";
import useFormValidator from "use-form-validator";
 
function Form() {
  // data is an object of form field values, .e.g {name: "Bob", email: "[e-mail]"}
  const [data, setData] = useState({});
  const [rules] = useState({
    name: "required|max:255",
    email: "required|max:255|email",
  });
  // Default message overrides
  const [messages] = useState({
    // Override default "required" message
    required: "This field is required",
    // Override "name.required" message
    name: {
      required: "Please enter your name",
    },
  });
  const validator = useFormValidator(data, rules, messages);
 
  // validator.valid => boolean if form validation state
  // validator.errors.all => array of form errors
  // validator.errors.get(name) => array of errors for field
  // validator.errors.first(name) => first error for field or null if there is no error
}

Basic Example

import React, { useState, useCallback } from "rect";
import useFormValidator from "use-form-validator";
 
function Form() {
  const [data, setData] = useState({});
  const [rules] = useState({
    name: "required|max:255",
    email: "required|max:255|email",
  });
  // Default message overrides
  const [messages] = useState({
    // Override default "required" message
    required: "This field is required",
    // Override "name.required" message
    name: {
      required: "Please enter your name",
    },
  });
  const validator = useFormValidator(data, rules, messages);
 
  const onSubmit = useCallback(
    (event) => {
      event.preventDefault();
      if (validator.valid) {
        // Validated data
        console.log(data);
      }
    },
    [validator]
  );
 
  const onChange = useCallback(
    ({ target: { name, value } }) => {
      setData((data) => {
        data[name] = value;
        return data;
      });
    },
    [setData]
  );
 
  return (
    <form onSubmit={onSubmit}>
      <div>
        {/* "name" error message */}
        <input name="name" onChange={onChange} />
        {validator.errors.first("name")}
      </div>
      <div>
        <input name="email" onChange={onChange} />
        {/* "email" error message */}
        {validator.errors.first("email")}
      </div>
      <div>
        <button>submit</button>
      </div>
    </form>
  );
}

Available Rules

Rule	Description
required	Test value has a value
min:min	Test value length or number is >= min
max:max	Test value length or number is <= max
email	Test value email format
between:min,max	Test value length or number between min and max

Contributing

All contributions are welcome, just submit a PR with a clear explanation of your changes.

Changes to the lib are made inside src/lib and changes to examples are made inside src/examples

Running Examples

The following commands will serve the examples on localhost:8081.

npm install
npm run watch-examples

Making a Release

The below script will bump the major, minor, or patch number by one and make a new NPM and Github release.

npm run release {release: ["major", "minor", "patch"]} # e.g. npm run release patch