Event listeners

[Andreyco]

Current Behavior

People complain about missing features e.g ability to register form level "on change" handler and so on...
Related issues #731, #669, #271, #231 and so on

Desired Behavior

Make it possible to create solutions in user land if form of "plugins" - components, yay!

Suggested Solution

Add ability to register event handler. This will open possibilities, keep Formik's codebase slim. Win win, I guess.

Who does this impact? Who is this for?

Consumers, package creators.

Describe alternatives you've considered

Your FormikPersist package. Which is great, if you only care about keeping changes in local storage. Speaking from my needs, I need to save changes on server. Throttling is not an option - you are either sending data too often, or not too often :)

Example for FormikUpdated

// Pseudocode

Formik {
  addEventListener(event, handler) {
    // register event handler
  }

  onBlur() {
    // do all stuff
    // call event listeners
  }
}

class FormikUpdated {
  constructor() {
    formik.addEventListener('blur', this.onBlur)
  }

  onBlur() {
    this.props.onUpdate(formik.values)
  }
}


<Formik>
  {() => (
    <FormikUpdated onUpdate={sendToServer} />
  )}
</Formik>

[jaredpalmer]

How is this different from formik-effect?

[Andreyco]

granularity of control. formik-effect runs on every key press. In most cases you only need to know form changed on field submit - blur event. Thus, need to subscribe to events.

[stale]

Hola! So here's the deal, between open source and my day job and life and what not, I have a lot to manage, so I use a GitHub bot to automate a few things here and there. This particular GitHub bot is going to mark this as stale because it has not had recent activity for a while. It will be closed if no further activity occurs in a few days. Do not take this personally--seriously--this is a completely automated action. If this is a mistake, just make a comment, DM me, send a carrier pidgeon, or a smoke signal.

[stale]

ProBot automatically closed this due to inactivity. Holler if this is a mistake, and we'll re-open it.