react

import React, { Component } from "react";

class IconList extends Component {
  static defaultProps = {
    options: [
      "angry",
      "anchor",
      "archive",
      "at",
      "archway",
      "baby",
      "bell",
      "bolt",
      "bone",
      "car",
      "city",
      "cloud",
      "couch"
    ]
  };
  constructor(props) {
    super(props);
    this.state = { icons: ["bone", "cloud"] };
    this.addIcon = this.addIcon.bind(this);
  }
  //DON'T DO THIS!!!!
  // addIcon() {
  //   let idx = Math.floor(Math.random() * this.props.options.length);
  //   let newIcon = this.props.options[idx];
  //   let icons = this.state.icons;
  //   icons.push(newIcon);
  //   this.setState({ icons: icons });
  // }

  addIcon() {
    // get random index
    let idx = Math.floor(Math.random() * this.props.options.length);
 	// get new element
    let newIcon = this.props.options[idx];
    // update the state of the icons array (spread icons into new array, add new icon to it)
    this.setState({ icons: [...this.state.icons, newIcon] });
  }
  render() {
    // render newly mapped icons array
    const icons = this.state.icons.map(i => <i className={`fas fa-${i}`} />);
    return (
      <div>
        <h1>Icons: {icons}</h1>
        <button onClick={this.addIcon}>Add New Icon</button>
      </div>
    );
  }
}

export default IconList;

//What are pure functions?
//Pure functions take an input value (a parameter or argument) and produce an output value. //Like with hashing, the same input it will always return the same output 

const myPureFunction = number => return number * 4

//Pure functions must:
//1. Contain no side effects
//2. When given the same input, return the same output.
// A pure component avoids any use of state.
map
filter
reduce

// This is what I've been using, pretty straight forward
// It passes the JSON to the children as props
// Of course, you fetch what you will
 
import React, { Component, Fragment } from 'react';
 
export class FetchJsonController extends Component
{
	constructor(props) {
		super(props);
		this.state = {
			data: null,
		};
	}
 
	componentDidMount() {
		fetch(this.props.src)
			.then(response => response.json())
			.then(data => {
				console.log(data);
				this.setState({ data })
			});
	}
 
	render() {
		const _data = this.state.data;
		const children = React.Children.map(this.props.children, child => {
			return React.cloneElement(child, {
				jsonData: _data
			});
		});
		return (
			<div>{ children }</div>
		)
	}
}
 
// This is how it's used
// SomeCompnent will receive the JSON data
<FetchJsonController src="somefile.json">
  <SomeComponent />
</FetchJsonController>

import React from 'react';

const names = ['James', 'John', 'Paul', 'Ringo', 'George'];

function App() {
  return (
    <div>
      {names.filter(name => name.includes('J')).map(filteredName => (
        <li>
          {filteredName}
        </li>
      ))}
    </div>
  );
}

export default App;

import React from 'react';

const people = [
  {
    name: 'James',
    age: 31,
  },
  {
    name: 'John',
    age: 45,
  },
  {
    name: 'Paul',
    age: 65,
  },
  {
    name: 'Ringo',
    age: 49,
  },
  {
    name: 'George',
    age: 34,
  }
];

function App() {
  return (
    <div>
      {people.filter(person => person.age < 60).map(filteredPerson => (
        <li>
          {filteredPerson.name}
        </li>
      ))}
    </div>
  );
}

export default App;

//app.js
import React, { useState } from 'react';
import './App.css';
import Switch from "./Switch";

function App() {
  const [value, setValue] = useState(false);
  return (
    <div className="app">
      <Switch
        isOn={value}
        onColor="#EF476F"
        handleToggle={() => setValue(!value)}
      />
    </div>
  );
}

export default App;

//Switch.js
import React from 'react';

const Switch = ({ isOn, handleToggle, onColor }) => {
  return (
    <>
      <input
        checked={isOn}
        onChange={handleToggle}
        className="react-switch-checkbox"
        id={`react-switch-new`}
        type="checkbox"
      />
      <label
        style={{ background: isOn && onColor }}
        className="react-switch-label"
        htmlFor={`react-switch-new`}
      >
        <span className={`react-switch-button`} />
      </label>
    </>
  );
};

export default Switch;

//css
.react-switch-checkbox {
  height: 0;
  width: 0;
  visibility: hidden;
}

.react-switch-label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  width: 100px;
  height: 50px;
  background: grey;
  border-radius: 100px;
  position: relative;
  transition: background-color .2s;
}

.react-switch-label .react-switch-button {
  content: '';
  position: absolute;
  top: 2px;
  left: 2px;
  width: 45px;
  height: 45px;
  border-radius: 45px;
  transition: 0.2s;
  background: #fff;
  box-shadow: 0 0 2px 0 rgba(10, 10, 10, 0.29);
}

.react-switch-checkbox:checked + .react-switch-label .react-switch-button {
  left: calc(100% - 2px);
  transform: translateX(-100%);
}

.react-switch-label:active .react-switch-button {
  width: 60px;
}

import React, { Component } from 'react';

class App extends Component {
  constructor(props) {
    super(props);
    this.state = {
      age: 0,
    };
  }
  
  // this.checkAge is passed as the callback to setState
  updateAge = (value) => {
    this.setState({ age: value}, this.checkAge);
  };

  checkAge = () => {
    const { age } = this.state;
    if (age !== 0 && age >= 21) {
      // Make API call to /beer
    } else {
      // Throw error 404, beer not found
    }
  };

  render() {
    const { age } = this.state;
    return (
      <div>
        <p>Drinking Age Checker</p>
        <input
          type="number"
          value={age}
          onChange={e => this.updateAge(e.target.value)}
        />
      </div>
    );
  }

}

export default App;

import React, { useEffect, useState } from 'react';

function App() {
  const [age, setAge] = useState(0);
  
  updateAge(value) {
    setDisplayUsaStudents(
            (prevDisplayUsaStudents) => !prevDisplayUsaStudents
          );
    setAge({prevAge: value});
  };

  useEffect(() => {
    if (age !== 0 && age >= 21) {
      // Make API call to /beer
    } else {
      // Throw error 404, beer not found
    }
//the square parentheses with the age state variable inside is called the dependency array. //it tells the useEffect function to listen for any changes to the state of age.
//when age changes, useEffect executes
  }, [age]);

  return (
    <div>
      <p>Drinking Age Checker</p>
      <input
        type="number"
        value={age} 
        onChange={e => setAge(e.target.value)}
      />
    </div>
  );
}

export default App;

//app.js
import React, { useState } from 'react';
import './App.css';

function App() {
  const [firstDieResult, setFirstDieResult] = useState(1);
  const [secondDieResult, setSecondDieResult] = useState(6);
  //OR
  //const [diceResult, setDiceResult] = useState({
  	//firstDieResult: 1,
  	//secondDieResult: 6,
	//});

  const firstDieImage = require(`./assets/${firstDieResult}.png`);
  const secondDieImage = require(`./assets/${secondDieResult}.png`);

  function rollDice() {
    setFirstDieResult(Math.floor(Math.random() * 6) + 1);
    setSecondDieResult(Math.floor(Math.random() * 6) + 1);
  }

  return (
    <div className="App">
      <header className="App-header">
        <div style={{ display: 'flex', margin: 20 }}>
          <img src={firstDieImage} className="die" alt="Die one" />
          <img src={secondDieImage} className="die" alt="Die two" />
        </div>
        <span>{firstDieResult + secondDieResult}</span>
        <button className="button" onClick={rollDice}>Roll</button>
      </header>
    </div>
  );
}

export default App;

//css

.App {
  text-align: center;
}

.App-header {
  background-color: #282c34;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-size: calc(16px + 2vmin);
  color: white;
}

.die {
  width: 50px;
  height: 50px;
  margin: 10px;
}

.button {
  margin-top: 20px;
  outline: none;
  animation: button-gradient 25s ease infinite;
  background-image: -webkit-linear-gradient(65deg,#21d4fd,#b721ff 50%,#017eff);
  background-image: linear-gradient(25deg,#21d4fd,#b721ff 50%,#017eff);
  background-size: 500%;
  border: none;
  border-radius: 3px;
  box-shadow: 0 3px 0 0 #5664a7;
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  height: 40px;
  width: 150px;
}

.button:hover {
  box-shadow: 0 2px 0 0 #5664a7;
}

.button:active {
  box-shadow: inset 0 2px 4px rgba(0,0,0,0.25), 0 1px 2px rgba(0,0,0,0.05);
}
// get images => https://upmostly.com/wp-content/uploads/react-dice-assets.zip

import React, { useState } from 'react'

const MyComponent = () => {
  const [toggle, setToggle] = useState(false)

  return(
    <>
      <button onClick={() => setToggle(!toggle)}>Toggle Dropdown Markup</button>
      {toggle && (
        <ul>
          <li>Show me</li>
          <li>Only when</li>
          <li>Toggle === true</li>
        </ul>
      )}
    </>
  )
}

//Provider Component
import React, { Component } from 'react';

// Create new context
const MyContext = React.createContext();

// Create the Provider that will pass down state and methods to the rest of the application.
class MyProvider extends Component {
  state = {
    name: 'Dominic',
    age: 28,
  };
  render() {
    return (
      <MyContext.Provider value={{
        state: this.state,
        addYear: () => this.setState({
          age: this.state.age + 1
        })
      }}>
        {this.props.children}
      </MyContext.Provider>
    )
  }
}

// Create the consumer that will consume the data provided by the Provider.
class Company extends Component {
  render() {
    return(
      <div className="company">
        <MyContext.Consumer>
          {(context) => (
            //Fragment added here since you can only return one child
            <>
              <p>Welcome to {context.state.name}</p>
              <p>We are {context.state.age} years old!</p>
              <button onClick={context.addYear}>Add Year</button>
            </>
          )}
        </MyContext.Consumer>
      </div>
    )
  }
}

// We'll nest our Consumer inside another component just to show that we don't need to pass props to each component.
const Companies = () => (
  <div>
    <Company />
  </div>
)

class App extends Component {
  render() {
    return (
      // Ensure the provider wraps all the components you want to share data between.
      <MyProvider>
        <div className="App">
          <Companies />
        </div>
      </MyProvider>
    );
  }
}

export default App;

//Using Inline Styles
import React from 'react';

function App() {
  return (
    <div
      style={{
        backgroundColor: 'blue',
        width: '100px',
        height: '100px'
      }}
    />
  );
}

export default App;

//Conditional Changing the Background Color in React
import React from 'react';

function App() {
  const isBackgroundRed = true;

  return (
    <div
      style={{
        backgroundColor: isBackgroundRed ? 'red' : 'blue',
      }}
    />
  );
}

export default App;

//OR

//App.js
import React from 'react';
import './App.css';

function App() {
  const isBackgroundRed = true;
  
  return (
    <div className={isBackgroundRed ? 'background-red' : 'background-blue'} />
  );
}

export default App;
//App.css
.background-red {
  background-color: red;
}

.background-blue {
  background-color: blue;
}

import React, { useState } from "react";
import "./App.css";

const App = () => {
  const [counterA, setCounterA] = useState(0);
  const [counterB, setCounterB] = useState(0);

  return (
    <div>
      <button
        onClick={() => {
          setCounterA(counterA + 1);
        }}
      >
        Increment A
      </button>
      <button
        onClick={() => {
          setCounterB(counterB + 1);
        }}
      >
        Increment B
      </button>
      <div>counterA: {counterA}</div>
      <div>counterB: {counterB}</div>
    </div>
  );
};

export default App;

const Nav = styled.div`
    div > a.active > div {
        color: ${props => props.color}
     }
`
function Header() {
    const {DefaultColor} = useContext(GlobalContext)
    return <Nav color={DefaultColor?.success} />
}