如何'重置'ReactJS元素？

Question

I'm trying to 'reset' a ReactJS element.

In this case, the element is 90%+ of the contents of the page.

I'm using replaceState to replace the state of the element with with its initial state.

Unfortunately, sub-elements which have their own 'state' do not reset. In particular, form fields keep their contents.

Is there a way of forcing a re-render of an element, which will also cause sub-elements to re-render, as if the page had just loaded?

Answer 1

Adding a key to the element forces the element (and all its children) to be re-rendered when that key changes.

(I set the value of 'key' to simply the timestamp of when the initial data was sent.)

render: function() {
  return (
    <div key={this.state.timestamp} className="Commissioning">
      ...

Answer 2

The this.replaceState(this.getInitialState()) method doesn't actually reset children that are inputs, if that's what you're looking for. For anyone looking to just reset their form fields, there is a standard DOM reset() function that will clear all the inputs in a given element.

So with React, it'd be something like this:

this.refs.someForm.getDOMNode().reset();

Doumentation:

https://developer.mozilla.org/en-US/docs/Web/API/HTMLFormElement/reset

Answer 3

If it is a form you want to reset, you simply can use this

// assuming you've given {ref: 'form'} to your form element
React.findDOMNode(this.refs.form).reset();

Answer 4

While I don't personally think you should store local, interim component state (like in-progress input boxes) in a centralized location (like a flux store) in most cases, here it may make sense, depending on how many you have, especially since it sounds like the inputs already have some server interaction/validation around them. Pushing that state up the component hierarchy or into some other central location may help a lot in this case.

One alternative idea off the top of my head is to use a mixin in components that might need to reset local state, and do some kind of event triggering, etc. to make it happen. For example, you could use Node's EventEmitter or a library like EventEmitter3 with a mixin like this (warning: not tested, maybe best this as pseudocode :)

var myEmitter = new EventEmitter(); // or whatever

var ResetStateMixin = {
  componentWillMount: function() {
    myEmitter.on("reset", this._resetState);
  },

  componentWillUnmount: function() {
    myEmitter.off("reset", this._resetState);
  },

  _resetState: function() {
    this.replaceState(this.getInitialState());
  },

  triggerReset: function() {
    myEmitter.emit("reset");
  }
};

Then you could use it in components like so:

React.createClass({
  mixins: [ResetStateMixin],

  getInitialState: function() {
    return { ... };
  },

  onResetEverything: function() {
    // Call this to reset every "resettable" component
    this.triggerReset();
  }
});

This is very basic and pretty heavy handed (you can only reset all components, every component calls replaceState(this.getInitialState()) , etc.) but those problems could be solved by extending the mixin a bit (eg having multiple event emitters, allowing component-specific resetState implementations, and so forth).

It's worth noting that you do have to use controlled inputs for this to work; while you won't need to push your state all the way up the component hierarchy, you'll still want all your inputs to have value and onChange (etc.) handlers.

Answer 5

You could also use

document.forms[0].reset()