Consider deprecating this in favor of @reach/component-component

[cloud-walker]

First of all, thanks again for the amazing work on formik, I've recently upgraded it from 0.* to 1.3 without breaking changes 😲!

I think this package brings not so much value considering more generic alternatives, like: https://ui.reach.tech/component-component

I propose to deprecate this redirecting the new users to the alternatives!

Comparison

// withFormikEffect.js
import React from 'react'
import ReactDOM from 'react-dom'
import {Formik, Form, Field} from 'formik'
import {Effect} from 'formik-effect'

const App = () => (
  <div>
    <h1>Formik with formik-effect</h1>
    <Formik onSubmit={console.log} initialValues={{nickname: '', password: ''}}>
      {formik => (
        <Form>
          <Effect
            onChange={(currentFormik, nextFormik) =>
              console.log(currentFormik, nextFormik)
            }
          />

          <Field name="nickname" />
          <Field name="password" />
          <input type="submit" />
        </Form>
      )}
    </Formik>
  </div>
)

const rootElement = document.getElementById('root')
ReactDOM.render(<App />, rootElement)

vs

// withComponentComponent.js
import React from 'react'
import ReactDOM from 'react-dom'
import {Formik, Form, Field} from 'formik'
import Component from '@reach/component-component'

const App = () => (
  <div>
    <h1>Formik with formik-effect</h1>
    <Formik onSubmit={console.log} initialValues={{nickname: '', password: ''}}>
      {formik => (
        <Form>
          <Component
            formik={formik}
            didUpdate={({prevProps, props}) => {
              console.log(prevProps.formik, props.formik)
            }}
          />

          <Field name="nickname" />
          <Field name="password" />
          <input type="submit" />
        </Form>
      )}
    </Formik>
  </div>
)

const rootElement = document.getElementById('root')
ReactDOM.render(<App />, rootElement)

The difference is minimal and u can do it in other ways also (for example passing only the formikBag props you want to Component)

[jedrichards]

@cloud-walker The <Effect/> API explicitly lets you mutate the Formik state as it passes through the onChange handler. What's the technique for doing the same in component-component's didUpdate?

[cloud-walker]

Hi @jedrichards, I'm not sure of what your are talking about, can you provide an example?

[jedrichards]

@cloud-walker Hmm, maybe I'm misunderstanding. As I understand it one of the use cases for <Effect/> was to trigger changes in the form state when a field changes. That is, when one field change should trigger a change in another field ... so changing a startDate field should automatically update an endDate field to be some date to the future of startDate (for example).

How would you do that within didUpdate in your example above?

[cloud-walker]

@jedrichards you mean something like this: https://codesandbox.io/s/ww1lv6386k

[jedrichards]

@cloud-walker Yeah exactly. Got it now - thanks! 🙇

[MikeSuiter]

@cloud-walker I'm trying to use your suggestion in my app to submit whenever a select field changes value and it works with Formik 1.3.X but not with 1.4.X. Somewhere in the Formik validation code (my form has no validation) it is setting isCanceled: true which I'm assuming keeps the handleSubmit() from getting called. More details on what's going on here:

https://github.com/jaredpalmer/formik/issues/1209

Here is the sandbox showing what I'm doing and that handleSubmit() doesn't get called with 1.4.1. If you change the Formik version to 1.3.2 it works.

I posted here in case you might know what's going on. I really want to use Component Component in a few places in our app but this is a blocker.

[cloud-walker]

Hi, why you need to do formik.submitForm manually? I've played with your example and to me it works just fine: https://codesandbox.io/s/p70o0plr4q

[MikeSuiter]

Kind of an edge case to submit a form on a field change but in our real app we have a select field that when changed will make a REST call to filter the grid contents. I think it's a better experience to submit the form on change rather than making them select then hit a button. The sandbox is a dumb example but did show what was going on.

Jared pointed me in a right direction and for this I'm not using Component-Component. There are some places where we need to update a field based on a value from another field so I want to try C-C there. Here is my solution for submitting on a select field change.

https://github.com/jaredpalmer/formik/issues/1209#issuecomment-450027026