formsy-react
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    2.2.5 • Public • Published

    formsy-react

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    A form input builder and validator for React.

    Quick Start API 1.x API

    Background

    christianalfoni wrote an article on forms and validation with React, Nailing that validation with React JS, the result of that was this library.

    The main concept is that forms, inputs, and validation are done very differently across developers and projects. This React component aims to be that “sweet spot” between flexibility and reusability.

    This project was originally located at christianalfoni/formsy-react if you're looking for old issues.

    What You Can Do

    1. Build any kind of form element components. Not just traditional inputs, but anything you want, and get that validation for free
    2. Add validation rules and use them with simple syntax
    3. Use handlers for different states of your form. (onSubmit, onValid, etc.)
    4. Pass external errors to the form to invalidate elements (E.g. a response from a server)
    5. Dynamically add form elements to your form and they will register/unregister to the form

    Install

    yarn add formsy-react react react-dom and use with webpack, browserify, etc.

    Formsy component packages

    1.x to 2.x Upgrade Guide

    The 2.0 release fixed a number of legacy decisions in the Formsy API, mostly a reliance on function props over value props passed down to wrapped components. However, the API changes are minor and listed below.

    • getErrorMessage() => errorMessage
    • getErrorMessages() => errorMessages
    • getValue() => value
    • hasValue() => hasValue
    • isFormDisabled(): => isFormDisabled
    • isFormSubmitted() => isFormSubmitted
    • isPristine() => isPristine
    • isRequired() => isRequired
    • isValid(): => isValid
    • showError() => showError
    • showRequired() => showRequired

    Quick Start

    1. Build a Formsy element

    // MyInput.js
    import { withFormsy } from 'formsy-react';
    import React from 'react';
    
    class MyInput extends React.Component {
      constructor(props) {
        super(props);
        this.changeValue = this.changeValue.bind(this);
      }
    
      changeValue(event) {
        // setValue() will set the value of the component, which in
        // turn will validate it and the rest of the form
        // Important: Don't skip this step. This pattern is required
        // for Formsy to work.
        this.props.setValue(event.currentTarget.value);
      }
    
      render() {
        // An error message is passed only if the component is invalid
        const errorMessage = this.props.errorMessage;
    
        return (
          <div>
            <input onChange={this.changeValue} type="text" value={this.props.value || ''} />
            <span>{errorMessage}</span>
          </div>
        );
      }
    }
    
    export default withFormsy(MyInput);

    withFormsy is a Higher-Order Component that exposes additional props to MyInput. See the API documentation to view a complete list of the props.

    2. Use your Formsy element

    import Formsy from 'formsy-react';
    import React from 'react';
    import MyInput from './MyInput';
    
    export default class App extends React.Component {
      constructor(props) {
        super(props);
        this.disableButton = this.disableButton.bind(this);
        this.enableButton = this.enableButton.bind(this);
        this.state = { canSubmit: false };
      }
    
      disableButton() {
        this.setState({ canSubmit: false });
      }
    
      enableButton() {
        this.setState({ canSubmit: true });
      }
    
      submit(model) {
        fetch('http://example.com/', {
          method: 'post',
          body: JSON.stringify(model),
        });
      }
    
      render() {
        return (
          <Formsy onValidSubmit={this.submit} onValid={this.enableButton} onInvalid={this.disableButton}>
            <MyInput name="email" validations="isEmail" validationError="This is not a valid email" required />
            <button type="submit" disabled={!this.state.canSubmit}>
              Submit
            </button>
          </Formsy>
        );
      }
    }

    This code results in a form with a submit button that will run the submit method when the form is submitted with a valid email. The submit button is disabled as long as the input is empty (required) and the value is not an email (isEmail). On validation error it will show the message: "This is not a valid email".

    3. More

    See the API for more information.

    Contribute

    • Fork repo
    • yarn
    • yarn lint runs lint checks
    • yarn test runs the tests
    • npm run deploy build and release formsy

    Changelog

    Check out our Changelog and releases

    License

    The MIT License (MIT)

    Install

    npm i formsy-react

    DownloadsWeekly Downloads

    35,072

    Version

    2.2.5

    License

    MIT

    Unpacked Size

    354 kB

    Total Files

    28

    Last publish

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