reactjs

问题 I am trying to post the states as data to MongoDB through Express and Node with Axios. class App extends React.Component { constructor(props){ super(props) this.state={ items: [{ desc:"Manage", price: 5000, purchased: false, }, { desc:"Deliver", price: 2000, purchased: false, }, { desc:"Market", price: 4000, purchased: false, } ], data:null, DisabledButton: true } } getAddedItems(){ return this.state.items.filter(item => item.purchased) } componentDidMount() { this.callApi() .then(res => this

问题 I am trying to post the states as data to MongoDB through Express and Node with Axios. class App extends React.Component { constructor(props){ super(props) this.state={ items: [{ desc:"Manage", price: 5000, purchased: false, }, { desc:"Deliver", price: 2000, purchased: false, }, { desc:"Market", price: 4000, purchased: false, } ], data:null, DisabledButton: true } } getAddedItems(){ return this.state.items.filter(item => item.purchased) } componentDidMount() { this.callApi() .then(res => this

问题 I am trying to post the states as data to MongoDB through Express and Node with Axios. class App extends React.Component { constructor(props){ super(props) this.state={ items: [{ desc:"Manage", price: 5000, purchased: false, }, { desc:"Deliver", price: 2000, purchased: false, }, { desc:"Market", price: 4000, purchased: false, } ], data:null, DisabledButton: true } } getAddedItems(){ return this.state.items.filter(item => item.purchased) } componentDidMount() { this.callApi() .then(res => this

问题 I'm writing a React.js application where I want to use Link component from react-router package in order to conditionally redirect a user to another page. If some condition doesn't hold I set the to prop to empty string which works and doesn't cause page reload and the page stays in the exact same place it was. But I'm wondering if this is the best practice? This is my solution: import { Link } from 'react-router'; <Link to={condition === true ? '/some/other/url' : ''}> <div> my content </div

问题 I'm trying to render a component recursively. On each recursive call I subtract 10 px from the dimensions. I expect a series of nested divs, each one 10px smaller. When the height and width reach 10px, the component should return null, so that is my base case. Instead of expected result, I've got nothing. No errors in the terminal, no errors in the dev tools, just a page that is frozen. Any thoughts? RecurentDiv.js : const RecurentDiv = ({ width, height }) => { const style = { width: `${width

问题 I am trying to get real-time data using Server-Sent Events from the Database Mysql and sending the value to the client Reactjs. Here is the code: server.js const mysql = require('mysql'); const app = require('express')() const fetch = require('node-fetch'); const con = mysql.createConnection({ host: 'localhost', user: 'root', password: 'root', database: 'databasetest', }); var increment = 0; app.get('/stream/:abc/:qwe', (request, response) => { console.log(`Request url: ${request.url}`); var

问题 I am trying to center an fab inside the circular progress bar. I was told I could use relative position for the parent and the children have absolute position. I would like to keep it responsive so if the screen is scaled down it will look the same. These are both Material UI components. <div className="event-dialog-header"> <DialogTitle id="form-dialog-title">Event Details</DialogTitle> <div className="event-dialog-delete"> { props.selectedEvent && <Fab aria-label="delete" size="small"

问题 I got a React functional Component with a callback inside. I want to define a struct outside the Component with a field which holds a reference to the callback, but not just the first definition it got, but it should hold every time the latest rendering of that callback to avoid closure issues. psuedo code of what I mean: let someStruct = { field: MyComponent.callback } const MyComponent = props => { const callback = () => { ...some code that depends on the state of MyComponent } } How can I

问题 I’m very much new to React Native currently i'm building a small app using expo. Currenttly i'm facing an issue when we type in the text fields continously the textinput slowing ie, in my project if the user enters 3 numbers in first field automatically it'll move on to next field. But if we do continous data submitting the switching of input from first one to second one is bit too slow. I could'nt find any solution for this. This is the working snack Snack This is the code that i've tried

问题 Has anyone successfully implemented CSRF protection for a form submitted with React (as a controlled component) to a Flask back-end (ideally with WTForms)? I've seen a lot of partial answers, and one with Django, but couldn't find anything definitive for Flask. My big issue seems to be that I don't know how to send the csrf token to my react front end, store it as a header before submitting my form, then submit my form with the correct token. Any direction would be really helpful. 回答1: So,