MERN Stack Build Part 2

Setup

Open terminal in frontend folder
Install react router and sass npm install react-router-dom sass
Create a file called styles.scss in the /src folder

Installing Router and Sass

Update index.js to like like so:

import React from "react";
import ReactDOM from "react-dom";
// IMPORT SCSS FILE TO BE SOURCE OF STYLING
import "./styles.scss";
// IMPORT ROUTER
import { BrowserRouter as Router } from "react-router-dom";
import App from "./App";
import reportWebVitals from "./reportWebVitals";

ReactDOM.render(
  <Router>
    <React.StrictMode>
      <App />
    </React.StrictMode>
  </Router>,
  document.getElementById("root")
);

// If you want to start measuring performance in your app, pass a function
// to log results (for example: reportWebVitals(console.log))
// or send to an analytics endpoint. Learn more: https://bit.ly/CRA-vitals
reportWebVitals();

Scoping Out Our Components

Create a components and pages folder
In the components folder create a Header.js and Main.js file
In the pages folder create a Index.js and Show.js folder
Write the component boilerplate and export the component in all the created files:

function Component(props){
  return <h1>Component Name</h1>;
} 

export default Component;

`App.js`

Our desired component Architecture:

-> App
  -> Header
  -> Main |state: people|
    -> Switch
      -> Route |path: "/"|
        -> Index |Props: people, createPeople|
      -> Route |path="/people/:id|
        -> Show |Props: people, updatePeople, deletePeople|

Let's add the following to App.js:

import "./App.css";
import Header from "./components/Header";
import Main from "./components/Main";

function App() {
  return (
    <div className="App">
      <Header />
      <Main />
    </div>
  );
}

export default App;

Setting up router in `Main.js`

Let's create our routes:

import { Route, Switch } from "react-router-dom";
import Index from "../pages/Index";
import Show from "../pages/Show";

function Main(props) {

  return (
    <main>
      <Switch>
        <Route exact path="/">
          <Index/>
        </Route>
        <Route
          path="/people/:id"
          render={(rp) => (
            <Show
              {...rp}
            />
          )}
        />
      </Switch>
    </main>
  );
}

export default Main;

Let's put the following in Header.js:

import { Link } from "react-router-dom";

function Header(props) {
  return (
    <nav className="nav">
      <Link to="/">
        <div>People App</div>
      </Link>
    </nav>
  );
}

export default Header;

Sass

Sass is a CSS pre-compiler that allows us some new tricks in writing CSS including...

Nesting
Mixin
Variables

Let's write some Sass in our styles.scss:

// --------------------------
// VARIABLES
// --------------------------
$maincolor: black;
$contrastcolor: white;

@mixin white-text-black-bg {
  color: $contrastcolor;
  background-color: $maincolor;
}

@mixin black-test-white-bg {
  color: $maincolor;
  background-color: $contrastcolor;
}

// --------------------------
// Header
// --------------------------

nav {
  @include white-text-black-bg;
  display: flex;
  justify-content: flex-start;

  a {
    @include white-text-black-bg;

    div {
      margin: 10px;
      font-size: large;
    }
  }
}

Displaying People in Index

We need the state to exist in Main so it can be shared between Index and Show.

So let's update Main to have:

State to hold our list of people
Function to make the api call for people
Function to create a new person
useEffect to make initial call for people list
Pass the people state and the create function to Index

Main.js

import { useEffect, useState } from "react";
import { Route, Switch } from "react-router-dom";
import Index from "../pages/Index";
import Show from "../pages/Show";

function Main(props) {
  const [ people, setPeople ] = useState(null);

  const URL = "http://localhost:4000/people/";

  const getPeople = async () => {
    const response = await fetch(URL);
    const data = await response.json();
    setPeople(data);
  };

  const createPeople = async (person) => {
    // make post request to create people
    await fetch(URL, {
      method: "POST",
      headers: {
        "Content-Type": "Application/json",
      },
      body: JSON.stringify(person),
    });
    // update list of people
    getPeople();
  };

  useEffect(() => getPeople(), []);

  return (
    <main>
      <Switch>
        <Route exact path="/">
          <Index people={people} createPeople={createPeople} />
        </Route>
        <Route
          path="/people/:id"
          render={(rp) => (
            <Show
              {...rp}
            />
          )}
        />
      </Switch>
    </main>
  );
}

export default Main;

Let's now display the people in Index.js:

import { Link } from "react-router-dom"

function Index(props) {

  // loaded function
  const loaded = () => {
    return props.people.map((person) => (
      <div key={person._id} className="person">
        <Link to={`/people/${person._id}`}><h1>{person.name}</h1></Link>
        <img src={person.image} alt={person.name} />
        <h3>{person.title}</h3>
      </div>
    ));
  };

  const loading = () => {
    return <h1>Loading...</h1>;
  };

  return props.people ? loaded() : loading();
}

export default Index;

Creating People

Let's now add a form to our Index.js:

State to hold the form data
Form inputs in our JSX
handleChange function to allow our state to control the form
handleSubmit function handle form submisssion

import { useState } from "react";
import { Link } from "react-router-dom"

function Index(props) {
  // state to hold formData
  const [ newForm, setNewForm ] = useState({
    name: "",
    image: "",
    title: "",
  });

  // handleChange function for form
  const handleChange = (event) => {
    setNewForm({ ...newForm, [event.target.name]: event.target.value });
  };

  // handle submit function for form
  const handleSubmit = (event) => {
    event.preventDefault();
    props.createPeople(newForm);
    setNewForm({
      name: "",
      image: "",
      title: "",
    });
  };

  // loaded function
  const loaded = () => {
    return props.people.map((person) => (
      <div key={person._id} className="person">
        <Link to={`/people/${person._id}`}><h1>{person.name}</h1></Link>
        <img src={person.image} alt={person.name} />
        <h3>{person.title}</h3>
      </div>
    ));
  };

  const loading = () => {
    return <h1>Loading...</h1>;
  };

  return (
    <section>
      <form onSubmit={handleSubmit}>
        <input
          type="text"
          value={newForm.name}
          name="name"
          placeholder="name"
          onChange={handleChange}
        />
        <input
          type="text"
          value={newForm.image}
          name="image"
          placeholder="image URL"
          onChange={handleChange}
        />
        <input
          type="text"
          value={newForm.title}
          name="title"
          placeholder="title"
          onChange={handleChange}
        />
        <input type="submit" value="Create Person" />
      </form>
      {props.people ? loaded() : loading()}
    </section>
  );
}

export default Index;

Conclusion

You should now be able to see all the people and create people.

Lab

Begin the frontend for your Cheese app, and create the ability to display and create cheeses like our People app.