I'm building a project with react styled components, And I need to check if checkbox is checked.
Now I'm doing it with react hook (usestate).
I would love to know if there is a built-in method that returns true or false
The two ways of handling forms with React are described (and documentation linked) below:
Controlled Components
In HTML, form elements such as , , and typically maintain their own state and update it based on user input. In React, mutable state is typically kept in the state property of components, and only updated with setState().
Uncontrolled Components
To write an uncontrolled component, instead of writing an event handler for every state update, you can use a ref to get form values from the DOM.
And also from the React documentation:
If you’re looking for a complete solution including validation, keeping track of the visited fields, and handling form submission, Formik is one of the popular choices. However, it is built on the same principles of controlled components and managing state — so don’t neglect to learn them.
Related
I'm wanting to migrate our front-end infrastructure off redux-form which seems to be largely abandoned now. We have projects with multiple forms that utilise the destroyOnUnmount={false} option set on the (redux-form) Form.
We have wizard type processes, and other CRUD type apps where a record is displayed across multiple tabs with a distinct form used on each tab, with react-router determining which form component is being rendered. Our custom field components use the field's meta information to visually display a fields validation state & error message based also on whether the field has been visited. When viewing a record that is split across multiple form components (in a multi-tab UI), a user needs to see the same form state when they switch back to a previously visited form.
In redux-form, the complete form state persists in the redux store when destroyOnUnmount={false} is set, which means when remounting the form component the complete state is rehydrated (visited, touched, error, etc). This is really useful as form component state is rehydrated when the component remounts.
I've looked at react-final-form & formik, and they don't appear to provide a way to save/restore the full form state across unmounting/remounting of the form component.
Are there other libraries that support this (and are well maintained), or perhaps there's a way to achieve this in formik/react-final-form that I'm missing?
It seems that you can achieve this using final-form
Create an instance of final-form:
import { createForm } from "final-form";
const form = createForm({onSubmit: fn});
Then, you can pass that form instance to the Form component:
<Form form={form}>
afaik, this way you can preserve form state across renders.
You can checkout react-hook-form.
Also, check out the wizard type process example here.
I working on a project that need to upgrade redux-form to react-final-form. I just wonder that is there any documentation for that task.
EDIT: 🎉🎉🎉 There is now a Migration Guide!! 🎉🎉🎉
I meant to make a migration guide, but it's just so easy that I never found the motivation to do it. But I'll write a little here for all of the people who find this excellent SEO-bait via Google.
Rather than "decorate" your form component with a HOC, you use 🏁 React Final Form's <Form> component inside your form component to give you all of your form state via a render prop. Most of the config stuff from Redux Form maps directly onto props to <Form>, e.g. initialValues, onSubmit, etc.
The <Field> API is nearly identical, but with the added benefit that you can define how your field is rendered inline via a render prop (using a "fat arrow" function as your component prop in Redux Form was forbidden and a common pitfall). 🏁 React Final Form has a few extra bits of field state, like dirtySinceLastSubmit, which can come in handy.
By default, Redux Form would not rerender your entire form on every value change, forcing you to use a getFormValues() selector if you needed them in realtime. React Final Form does rerender on every value change by default because for most small forms, this is just fine. But 🏁 React Final Form allows fine tuning of rerendering via providing a subscription prop to <Form>, specifying exactly which pieces (slices) of form state you want to rerender for. Then, any time you were using a selector in Redux Form, you would use a <FormSpy> component in 🏁 React Final Form, which allows you to subscribe ("select") parts of the form state to rerender for.
As linked in the other answer, this talk explains the difference pretty well. More talks will be given later in 2019.
I am trying to find a lib to use for my forms, to handle validation and stuff, and I come across redux-form which seems to be the most popular one.
There is one thing that troubles me with it though. In FieldArray example https://redux-form.com/7.2.3/examples/fieldarrays/ they modify props to add/remove fields. Isn't that actually anti-pattern which conflicts with functional programming principles?
From the docs: https://redux-form.com/7.3.0/docs/api/fieldarray.md/
fields.push(value:Any) : Function
Adds a value to the end of the array. Returns nothing.
This is not a mutator; it dispatches an action which updates the state in Redux, which will cause your component to rerender.
I am using SurveyJS to quickly build a survey form in React/Redux.
I implemented a custom widget using a React component for Google Maps Places Autocomplete. My problem is that once suggestions appear and the field state changes, the contents of all the other survey fields get cleared. Is there a way to prevent it?
Here's what I did to integrate React Places Autocomplete into the survey as a custom widget.
As soon as you select the Address field the onChange is called, the component loses the state for the other fields.
"setState() will always lead to a re-render unless shouldComponentUpdate() returns false. If mutable objects are being used and conditional rendering logic cannot be implemented in shouldComponentUpdate(), calling setState() only when the new state differs from the previous state will avoid unnecessary re-renders." from reactjs.org
I am new on react. I am working on react application with redux. I have a form (I am using redux-form) by which I can save data or edit data.
my problem is , In edit mode I populate data using componentWillReceiveProps. and populated perfectly, now when I try to clear any field on form its again fill.
componentWillReceiveProps(nextProps){
this.props.dispatch(initialize('NewProject', nextProps.project.project[0]));
}
I would be grateful for any help.
Is there a reason you're not dispatching this action somewhere else, like in componentDidMount? I can't say without seeing more code, but it's possible that whenever you edit your form, React again calls componentWillReceiveProps and overwrites whatever you did with the behavior you've given your component.
Per the React documentation:
Note that React may call this method even if the props have not changed, so make sure to compare the current and next values if you only want to handle changes. This may occur when the parent component causes your component to re-render.
It may be a good idea for you to move your dispatch to a more predictable event if possible, like componentDidMount. Typically, your render method should be capable of handling different cases if a component has multiple possible states. You could also create an edit and save version of your component, and render one or the other based on the props you receive. The best way to "populate" data, as you put it, is to define propTypes for your component, and then use your props to insert that data into elements in the render method.