通过仅传递一次道具多次执行状态和数组操作

Question

I am new to React and this thing is confusing me a lot. I have root component that has an array and I am passing functions ADD and DELETE as props to the child component ui_forms . In the child component, I am taking input parameters and pushing or deleting from array depending on the button pressed. However, I cannot seem to perform push/delete operation more than once because I guess I am injecting the child component only once in the root component.

Is there by any chance a way to perform push or delete as many times a user wants by sending props only once?

Thank you

App.js

import FormsMap from './form_map';

class App extends Component {
  state = {
    maps : [
      {'regno' : 'Karan', 'id' : 1},
      {regno : 'Sahil', 'id' : 2},
      {'regno' : 'Rahul', id : 4},
      {regno : 'Mohit', id : 5},
      {regno : 'Kartik', id : 3}
    ]
  };

   function_as_props(list1) {
      console.log(this.state.maps);
      let ninja = [...this.state.maps];
      console.log(ninja);
      ninja.push({"regno" : list1, "id" : Math.random()*10});

      this.setState({
        maps : ninja 
      });
    console.log(ninja);


    function_as_props1(name) {
       let t = this.state.maps.indexOf(name);  
       let x = this.state.maps.splice(t,1);
       console.log(x);
       this.setState({
         maps : x
       });
       console.log(this.state.maps);
    }
  }

  render() {
      const p = this.state.maps.map(list => {
        return(
           <div key={list.id}> {list.regno} </div>
        );
       })

 return(
   <FormsMap transpose = {this.function_as_props.bind(this)}  traverse ={this.function_as_props1.bind(this)} /> <br />
 );


} 
}

export default app;

form_map.js

import React, { Component } from 'react';

class FormsMap extends Component {
    state = {
        name : null,
        age : null,
        hobby : null
    };

    changes(e) {
        this.setState({
            [e.target.id] : e.target.value
        });
    }

    handle = (e) => {
        e.preventDefault();
        console.log(this.state);
        this.props.transpose(this.state.name);
    }

    dels = (e) => {
        this.setState({
            [e.target.id] : e.target.value
        });
    }

    del_button(e) {
        e.preventDefault();
        //console.log(this.state.name);
        this.props.traverse(this.state.name);
    }
    render() {
        return(
            <React.Fragment>
            <form onSubmit={this.handle}>   {/* After entering all info, Press Enter*/}
                <label htmlFor="labels"> Name : </label>  
                <input type="text" id="name" placeholder="Your name goes here..." onChange={this.changes.bind(this)} />
                <label htmlFor="labels"> Age : </label>  
                <input type="text" id="age" placeholder="Your age goes here..." onChange={this.changes.bind(this)} />
                <label htmlFor="labels"> Hobby : </label>  
                <input type="text" id="hobby" placeholder="Your hobby goes here..." onChange={this.changes.bind(this)} /> <br /><br />
                <input type="submit" value="SUBMIT" /><br /><br />
            </form>

            <input type="text" id="name" placeholder="Enter name to delete..." onChange={this.dels} />   <button onClick={this.del_button.bind(this)}> DELETE </button>
            </React.Fragment>

        );
    }
}

export default FormsMap;

Answer 1

Try this

---

App.js

import React, { Component } from "react";
import FormsMap from "./components/FormsMap";

class App extends Component {
  constructor(props) {
    super(props);
    this.state = {
      maps: [
        { regno: "Karan", id: 1 },
        { regno: "Sahil", id: 2 },
        { regno: "Rahul", id: 4 },
        { regno: "Mohit", id: 5 },
        { regno: "Kartik", id: 3 }
      ]
    };
  }
  function_as_props(list1) {
    let ninja = this.state.maps.concat({
      regno: list1,
      id: Math.random() * 10
    });
    this.setState({ maps: ninja });
  }
  function_as_props1(name) {
    let x = this.state.maps.filter(
      list => list.regno.toLocaleLowerCase() !== name.toLocaleLowerCase()
    );
    this.setState({
      maps: x
    });
  }
  render() {
    return (
      <React.Fragment>
        {this.state.maps.map(list => <div key={list.id}>{list.regno}</div>)}
        <FormsMap
          transpose={this.function_as_props.bind(this)}
          traverse={this.function_as_props1.bind(this)}
        />
      </React.Fragment>
    );
  }
}

export default App;

---

FormsMap.js

import React, { Component } from "react";

class FormsMap extends Component {
  state = {
    name: null,
    age: null,
    hobby: null
  };

  changes(e) {
    this.setState({
      [e.target.id]: e.target.value
    });
  }

  handle = e => {
    e.preventDefault();
    this.props.transpose(this.state.name);
  };

  dels = e => {
    this.setState({
      [e.target.id]: e.target.value
    });
  };

  del_button(e) {
    e.preventDefault();
    this.props.traverse(this.state.name);
  }
  render() {
    return (
      <React.Fragment>
        <form onSubmit={this.handle}>
          {" "}
          {/* After entering all info, Press Enter*/}
          <label htmlFor="labels"> Name : </label>
          <input
            type="text"
            id="name"
            placeholder="Your name goes here..."
            onChange={this.changes.bind(this)}
          />
          <label htmlFor="labels"> Age : </label>
          <input
            type="text"
            id="age"
            placeholder="Your age goes here..."
            onChange={this.changes.bind(this)}
          />
          <label htmlFor="labels"> Hobby : </label>
          <input
            type="text"
            id="hobby"
            placeholder="Your hobby goes here..."
            onChange={this.changes.bind(this)}
          />{" "}
          <br />
          <br />
          <input type="submit" value="SUBMIT" />
          <br />
          <br />
        </form>
        <input
          type="text"
          id="name"
          placeholder="Enter name to delete..."
          onChange={this.dels}
        />{" "}
        <button onClick={this.del_button.bind(this)}> DELETE </button>
      </React.Fragment>
    );
  }
}

export default FormsMap;

---

This is the demo: https://codesandbox.io/s/xl97xm6zpo