setState() has an optional callback parameter that you can use for this. You only need to change your code slightly, to this: // Form Input this.setState( { originId: input.originId, destinationId: input.destinationId, radius: input.radius, search: input.search }, this.findRoutes // here is where you put the callback ); Notice the call to findRoutes is now inside the … Read more
This is a known use case. There are different solutions. For example, one can use vuex-persistedstate. This is a plugin for vuex to handle and store state between page refreshes. Sample code: import { Store } from ‘vuex’ import createPersistedState from ‘vuex-persistedstate’ import * as Cookies from ‘js-cookie’ const store = new Store({ // … … Read more
setState() is usually asynchronous, which means that at the time you console.log the state, it’s not updated yet. Try putting the log in the callback of the setState() method. It is executed after the state change is complete: this.setState({ dealersOverallTotal: total }, () => { console.log(this.state.dealersOverallTotal, ‘dealersOverallTotal1’); });
I think this provides a more thorough approach: button, input[type=”submit”], input[type=”reset”] { background: none; color: inherit; border: none; padding: 0; font: inherit; cursor: pointer; outline: inherit; } <button>Example</button>
I work on React. TLDR: But can you trust React to update the state in the same order as setState is called for the same component? Yes. different components? Yes. The order of updates is always respected. Whether you see an intermediate state “between” them or not depends on whether you’re inside in a batch … Read more
Reducer is never an appropriate place to do this because reducers should be pure and have no side effects. I would recommend just doing it in a subscriber: store.subscribe(() => { // persist your state }) Before creating the store, read those persisted parts: const persistedState = // … const store = createStore(reducer, persistedState) If … Read more
The major difference between React.PureComponent and React.Component is PureComponent does a shallow comparison on state change. It means that when comparing scalar values it compares their values, but when comparing objects it compares only references. It helps to improve the performance of the app. You should go for React.PureComponent when you can satisfy any of … Read more
I think this is a much simpler version. Bundle is a built-in type which implements Parcelable public class CustomView extends View { private int stuff; // stuff @Override public Parcelable onSaveInstanceState() { Bundle bundle = new Bundle(); bundle.putParcelable(“superState”, super.onSaveInstanceState()); bundle.putInt(“stuff”, this.stuff); // … save stuff return bundle; } @Override public void onRestoreInstanceState(Parcelable state) { if … Read more
Or if you play a video game, there are tons of state variables, beginning with the positions of all the characters, who tend to move around constantly. How can you possibly do anything useful without keeping track of changing values? If you’re interested, here’s a series of articles which describe game programming with Erlang. You … Read more
Here’s how you can do it without helper libs: handleChange: function (e) { // 1. Make a shallow copy of the items let items = […this.state.items]; // 2. Make a shallow copy of the item you want to mutate let item = {…items[1]}; // 3. Replace the property you’re intested in item.name=”newName”; // 4. Put … Read more