ReactFormBuilder
# React JSON Form Builder See example page: [https://alexanderweigelt.github.io/ReactFormBuilder/](https://alexanderweigelt.github.io/ReactFormBuilder/) ## The Task 1. Create a new React component called `FormBuilder` that will be responsible for rendering the form fields based on the provided data schema. 2. The `FormBuilder` component should accept a `schema` prop, which is a JSON object that describes the data schema. The schema should specify the types of fields that should be rendered, along with any validation rules or other requirements. 3. The `FormBuilder` component should parse the `schema` prop and generate the appropriate form fields based on the specified types. For example, if the schema specifies a text input field, the component should render an `<input>` element with the appropriate attributes and validation rules. 4. To keep the component lightweight, you can use existing React form libraries like `react-hook-form` or `formik` to handle form validation and submission. Decide which library is appropriate. 5. Use `Yup` to generate a validation schema based on the `schema` prop. 6. You can also add additional features like conditional logic, custom field types, and styling options to make the form builder more flexible and customizable. Here's some sample code to get you started: Example schema file content for the component props to generate a form with the following fields: - first name - last name - street name - street number - postal code - city - country: ```js const schema = { fields: [ { name: 'firstName', label: 'First Name', type: 'text', validation: yup.string().required('First name is required'), }, { name: 'lastName', label: 'Last Name', type: 'text', validation: yup.string().required('Last name is required'), }, { name: 'streetName', label: 'Street Name', type: 'text', validation: yup.string().required('Street name is required'), }, { name: 'streetNumber', label: 'Street Number', type: 'number', validation: yup.number().required('Street number is required'), }, { name: 'postalCode', label: 'Postal Code', type: 'text', validation: yup.string().required('Postal code is required'), }, { name: 'city', label: 'City', type: 'text', validation: yup.string().required('City is required'), }, { name: 'country', label: 'Country', type: 'text', validation: yup.string().required('Country is required'), }, ], }; ``` In this schema file, we're defining an array of field objects, where each object represents a form field. Each field object has a `name` property, which is used as the `name` attribute of the form field, a `label` property, which is used as the label of the form field, a `type` property, which is used as the `type` attribute of the form field, and a `validation` property, which is used as the validation schema for the form field. In this example, we're using the Yup validation library to define the validation schema for each field. We're using the `required` method to ensure that each field is required. For the `streetNumber` field, we're using the `number` method to ensure that the field value is a number. ## Variant 1: `react-hook-form` This variant was created with react-hook-form and yup-schema form validation. ### What is react-hook-form? `react-hook-form` is a library for managing forms in React using hooks. It has a small API and is focused on performance. `react-hook-form` uses uncontrolled components, which means that it doesn't store the form data in state. Instead, it uses `ref`s to access the form data directly. ### Code example Code example with `react-hook-form` that uses Yup for validation: ```jsx import React from 'react'; import { useForm } from 'react-hook-form'; import * as yup from 'yup'; const FormBuilder = ({ schema }) => { const validationSchema = yup.object().shape( schema.fields.reduce((schemaObj, field) => { schemaObj[field.name] = field.validation || yup.string(); return schemaObj; }, {}) ); const { register, handleSubmit, errors } = useForm({ validationSchema, }); const onSubmit = (data) => { console.log(data); }; const renderField = (field) => { switch (field.type) { case 'text': return ( <div> <label>{field.label}</label> <input type="text" name={field.name} ref={register} /> {errors[field.name] && <span>{errors[field.name].message}</span>} </div> ); case 'number': return ( <div> <label>{field.label}</label> <input type="number" name={field.name} ref={register} /> {errors[field.name] && <span>{errors[field.name].message}</span>} </div> ); // Add additional field types as needed default: return null; } }; return ( <form onSubmit={handleSubmit(onSubmit)}> {schema.fields.map((field) => renderField(field))} <button type="submit">Submit</button> </form> ); }; export default FormBuilder; ``` In this code, we're using Yup to generate a validation schema based on the `schema` prop. We're also passing the validation schema to `useForm` to handle form validation. Note that we're using the `validation` property of each field in the `schema` prop as the validation schema for that field. If the `validation` property is not specified for a field, we're defaulting to a `yup.string()` validation schema. ## Variant 2: `Formik` Use Formik instead of react-hook-form and Yup schema form validation ### What is Formik? `Formik` is a library for managing forms in React. It uses controlled components, which means that it stores the form data in state. `Formik` provides a set of components and hooks to help you manage form state, validation, and submission. ### Code example Code example with `Formik` that uses Yup for validation: ```jsx import React from 'react'; import { Formik, Field, Form } from 'formik'; import * as yup from 'yup'; const FormBuilder = ({ schema }) => { const validationSchema = yup.object().shape( schema.fields.reduce((schemaObj, field) => { schemaObj[field.name] = field.validation || yup.string(); return schemaObj; }, {}) ); const initialValues = schema.fields.reduce((valuesObj, field) => { valuesObj[field.name] = field.value || ''; return valuesObj; }, {}); const onSubmit = (values) => { console.log(values); }; const renderField = (field) => { switch (field.type) { case 'text': return ( <div> <label>{field.label}</label> <Field type="text" name={field.name} /> <ErrorMessage name={field.name} /> </div> ); case 'number': return ( <div> <label>{field.label}</label> <Field type="number" name={field.name} /> <ErrorMessage name={field.name} /> </div> ); // Add additional field types as needed default: return null; } }; return ( <Formik initialValues={initialValues} onSubmit={onSubmit} validationSchema={validationSchema} > {({ errors }) => ( <Form> {schema.fields.map((field) => renderField(field))} <button type="submit">Submit</button> </Form> )} </Formik> ); }; export default FormBuilder; ``` In this updated code, we're using Formik to handle form validation and submission. We're also using the `Field` and `ErrorMessage` components provided by Formik to render the form fields and error messages. **Note that we're using the `validation` property of each field in the `schema` prop as the validation schema for that field.** If the `validation` property is not specified for a field, we're defaulting to a `yup.string()` validation schema. We're also using the `value` property of each field in the `schema` prop as the initial value for that field. If the `value` property is not specified for a field, we're defaulting to an empty string. ## Decision for a library React has a plethora of libraries and frameworks for form management, but two of the most popular are `react-hook-form` and `Formik`. Both libraries provide similar functionality, but they approach form management in different ways. In this article, we'll compare `react-hook-form` and `Formik` and make a decision on which one to use. ### Comparing `react-hook-form` and `Formik` #### API `react-hook-form` has a smaller and simpler API than `Formik`. `react-hook-form` provides a `useForm` hook, which returns a set of functions and values that you can use to manage your form. `Formik` provides a `Formik` component and a set of hooks that you can use to manage your form state, validation, and submission. #### Performance `react-hook-form` is focused on performance and has a small bundle size. It uses uncontrolled components, which means that it doesn't store the form data in state. Instead, it uses `ref`s to access the form data directly. This approach avoids the performance overhead of controlled components. `Formik` uses controlled components, which means that it stores the form data in state. This approach can lead to performance issues, especially with large forms. However, `Formik` provides a `shouldUpdate` prop that you can use to optimize performance. #### Validation Both `react-hook-form` and `Formik` provide validation functionality. `react-hook-form` uses the `yup` library for validation, while `Formik` provides its own validation API. #### Community and Documentation Both libraries have a large and active community, and both have comprehensive documentation. However, `Formik` has been around longer and has a more mature ecosystem, which means that it has more third-party integrations and plugins. #### Learning Curve `react-hook-form` has a smaller and simpler API than `Formik`, which makes it easier to learn. However, `Formik` has more features and functionality, which means that it has a steeper learning curve. ### Which one should we use? Both `react-hook-form` and `Formik` are solid choices for managing forms in React. `react-hook-form` is focused on performance and simplicity, while `Formik` provides more features and functionality. If you're building a small form or a form with simple validation, `react-hook-form` is a good choice. It has a small API and is focused on performance. However, if you're building a large and complex form, `Formik` is a better choice. It provides more features and functionality, and has a more mature ecosystem. In summary, the choice between `react-hook-form` and `Formik` depends on the size and complexity of your form. Since we want to implement large and complex forms it is a good decision to use `Formik`. ## Development In the project directory, you can run: #### `npm start` Runs the app in the development mode.\ Open [http://localhost:3000](http://localhost:3000) to view it in the browser. The page will reload if you make edits.\ You will also see any lint errors in the console. #### `npm test` Launches the test runner in the interactive watch mode.\ See the section about [running tests](https://facebook.github.io/create-react-app/docs/running-tests) for more information. #### `npm run build` Builds the app for production to the `build` folder.\ It correctly bundles React in production mode and optimizes the build for the best performance. The build is minified and the filenames include the hashes.\ Your app is ready to be deployed! See the section about [deployment](https://facebook.github.io/create-react-app/docs/deployment) for more information. #### `npm run eject` **Note: this is a one-way operation. Once you `eject`, you can’t go back!** If you aren’t satisfied with the build tool and configuration choices, you can `eject` at any time. This command will remove the single build dependency from your project. Instead, it will copy all the configuration files and the transitive dependencies (webpack, Babel, ESLint, etc) right into your project so you have full control over them. All of the commands except `eject` will still work, but they will point to the copied scripts so you can tweak them. At this point you’re on your own. You don’t have to ever use `eject`. The curated feature set is suitable for small and middle deployments, and you shouldn’t feel obligated to use this feature. However we understand that this tool wouldn’t be useful if you couldn’t customize it when you are ready for it. ## Deployment Deploy React app to GitHub Pages #### `npm run deploy` We can deploy our React application by simply running: `npm run deploy`. This will create a bundled version of our React application and push it to a gh-pages branch in our remote repository on GitHub.