7.03 Splitting App Into Components

Refactor App.js

App.js

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

...

  render() {
    let persons = null;

    if (this.state.showPersons) {
      persons = (
        <Persons
          persons={this.state.persons}
          clicked={this.deletePersonHandler}
          changed={this.nameChangedHandler}
        />
      );
    }

    return (
      <div className={classes.App}>
        <Cockpit
          persons={this.state.persons}
          showPersons={this.state.showPersons}
          clicked={this.togglePersonsHandler}
        />
        {persons}
      </div>
    );
  }
}

export default App;

New Persons.js

Persons.js

import React from "react";
import Person from "./Person/Person";

const persons = (props) =>
  props.persons.map((person, index) => {
    return (
      <Person
        click={() => props.clicked(index)}
        name={person.name}
        age={person.age}
        key={person.id}
        changed={(event) => props.changed(event, person.id)}
      />
    );
  });

export default persons;

New Cockpit.js

Cockpit.js

import React from "react";
import classes from "./Cockpit.css";

const cockpit = (props) => {
  const assignedClasses = [];
  let btnClass = "";
  if (props.showPersons) btnClass = classes.Red;
  if (props.persons.length <= 2) {
    assignedClasses.push(classes.red); // classes = ['red']
  }
  if (props.persons.length <= 1) {
    assignedClasses.push(classes.bold); // classes = ['red', 'bold']
  }
  return (
    <div className={classes.Cockpit}>
      <h1>Hi, I'm a React app!</h1>
      <p className={assignedClasses.join(" ")}>This is really working!</p>
      <button className={btnClass} onClick={props.clicked}>
        Toggle Persons
      </button>
    </div>
  );
};

export default cockpit;

Refactor App.css

App.css

.App {
  text-align: center;
}

New Cockpit.css

Cockpit.css

.red {
  color: red;
}

.bold {
  font-weight: bold;
}

.Cockpit button {
  background-color: green;
  color: white;
  font: inherit;
  border: 1px solid blue;
  padding: 8px;
  cursor: pointer;
}

.Cockpit button:hover {
  background-color: lightgreen;
  color: #333;
}

.Cockpit button.Red {
  background-color: red;
}

.Cockpit button.Red:hover {
  background-color: salmon;
}