codeup-web-exercises/promise-lecture.html at main · marcusmz/codeup-web-exercises · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Promises Lecture</title>

    <!--    To color the code in the page-->
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>

    <style>
        body {
            background-color: #9ca3af;
        }

        #pokemon {
            width: 80%;
            display: flex;
            gap: 10px;
            flex-wrap: wrap;
            margin: auto;
            justify-content: space-around;
        }

        .pokemon {
            border-radius: 5px;
            background-color: white;
            padding: 10px;
        }


        #disney {
            margin-right: auto;
            margin-left: auto;
            width: 80%;
        }

        #disney ul {
            padding: 0;
            list-style: none;
            display: flex;
            flex-wrap: wrap;
            justify-content: space-evenly;
            gap: 20px;
            text-align: center;

        }

        #disney ul li {
            background-color: white;
        }

        #disney ul img {
            min-width: 200px;
            min-height: 200px;
            max-width: 200px;
            max-height: 200px;
        }

        #disneyButtons {
            display: flex;
            justify-content: space-evenly;
        }
    </style>
</head>

<body>

<header>
    <!--Search for Pokemon-->
    <label for="search">Search:</label> <input id="search" type="text">
</header>

<div id="pokemon">
    <!--    Div to hold returned pokemon from api-->
</div>

<div id="disney">
    <!--    Div to hold returned characters from api-->
</div>

<div id="disneyButtons">
    <button id="prev" value="prev">Prev</button>
    <div id="current">0</div>
    <button id="next" value="next">Next</button>
</div>

</body>

<script>

    // TODO: Promises Lecture

    // Promise States
    // wait for something to happen multiple events can happen at the same time.


    // Define: Pending - in this state as soon as you create it.

    // Define: Resolved - resolve() is called by the internal function. Is in this state when it is complete.

    // Define: Rejected - reject() is called by the internal function, error handling goes here. Happens when it
    // is rejected by the function


    // TODO: Explain Async vs Sync

    // Define: Async - Asynchronous - without being in sync with other things. multiple running at once, they can
    // finish at different times as well.

    // Define: Sync - write a line then the next line then the next. a,b,c Locking

    // ASK: What are potential pitfalls doing things each way?  they can run out of order, can mess each other up.
    // data you need doesent exist yet.

    // TODO: Creating our first promises


    // Example:
    const getRandom = (resolve, reject) => {
        const isResolved = (Math.random() > 0.6)

        if(isResolved) {
            resolve("Resolved!"); // IF something went well ->  resolve
        } else {
            reject("Rejected!"); // IF Something went bad  ->  reject
        }
    }

    const getResolved = (resolve) => {
        return resolve("Resolved!")
    }

    const getRejected = (resolve, reject) => {
        return reject("Rejected!!s");
    }

    const myFirstPromise = new Promise(getRandom);

    console.log("myFirstPromise:", myFirstPromise)

    // Explain: then and catch

    myFirstPromise.then(
        (response) => {
            console.log("inline handler: response :", response);
            // what am i going to do next?
        } ).catch((response) => {
        console.log("inline handler: response bad : ", response);
    })

    const handlerGood = (res) => console.log("res :", res);
    const handlerBad = (res) => console.log("res bad:", res);

    myFirstPromise.then(handlerGood).catch(handlerBad);

    myFirstPromise.then(handlerGood, handlerBad);


    // TODO: Chaining

    // Explain: Promise Chaining
    // This allows us to ensure one promise completes before another one.
    // Promise A, followed by Promise B, ...
    // We might need to get something from Promise A as a requirement for promise B

    // Example:

    const myNewFirstPromise = new Promise(getResolved);

    myNewFirstPromise.then((res) => {
        console.log("first response:", res);
        const mySecondPromise = new Promise(getResolved)
        // we ensure the second promise happens after the first.
        return mySecondPromise;
    }).then((res) => {
        //to do another thing with it
        console.log("second response", res);
    }).catch();


    // TODO: .all vs .race (Smarter chaining)

    // Define: .all
    // .all () -> accepts an array of promises! returns an array of responses

    // Define: .race
    // accepts an array of promises, returns when first promise resolves.

    const p1 = new Promise((resolve, reject) => {
        setTimeout(() => {
            console.log('The first promise has rejected');
            reject(10);
        }, 1000);
    });
    const p2 = new Promise((resolve, reject) => {
        setTimeout(() => {
            console.log('The second promise has resolved');
            resolve(20);
        }, 2000);
    });
    const p3 = new Promise((resolve, reject) => {
        setTimeout(() => {
            console.log('The third promise has resolved');
            resolve(30);
        }, 3000);
    });

    //Example: Write .all method to collect the results of the 3 promises above

    const handleGoodAll = (responses) => {
        console.log("responses:", responses)
        const total = responses.reduce((p,c) => p + c);
        console.log("total",total);
    }

    const handleBadAll = (responses) => {
        console.log("bad all - responses:", responses)
    }

    Promise.all([p1,p3,p2]).then(
        handleGoodAll, handleBadAll
    ).catch((res) => {
        console.log(res);
    });


    //TODO: Fetch API
    // https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API
    // explain: fetch is the native way to grab data from the web. Its similar to the jquery method $.get()

    // Define: Resource Link

    const resourceLink = "https://someLink.com/endpoint"

    // Define: Settings object

    const potentialSettingsObject = {
        method: "POST", // or get
        headers: "Important headers",
        body: "data in body"
    }

    // fetch(resourceLink, potentialSettingsObject).then(() => {})
    // is a promise!

    //Example:
    //TODO: Get a pokemon from the API using fetch. Add it to the page.

    //https://pokeapi.co/docs/v2#pokemon
    const pokemonAPI = "https://pokeapi.co/api/v2/pokemon/"

    const getSinglePokemon =
        fetch(pokemonAPI + "clefairy")
            .then((res) => res.json())
            .then((res) => createPokemon(res));

    const createPokemon = ({ name, sprites, stats}) => {
        document.getElementById("pokemon").innerHTML +=
            `<div class="pokemon">
                    <h3>${name}</h3>
                    <img src="${sprites.front_default}">
                      <ul>
                        ${stats.map(({base_stat, stat}) => {
                return `<li>${stat.name} - ${base_stat}</li>`}).join("")}
                    </ul>
                </div>`;
    };


    //TODO: Multiple pokemon at once! (All vs Race)

    const clefairy = fetch(pokemonAPI + "clefairy");
    const pikachu = fetch(pokemonAPI + "pikachu");
    const charmander = fetch(pokemonAPI + "charmander");
    const squirtle = fetch(pokemonAPI + "squirtle");

    const arrayOfPokemon = [clefairy, pikachu, charmander, squirtle]; // Promises!

    // Example: .forEach

    // arrayOfPokemon.forEach((name) => {
    //     name.then((res) => res.json())
    //         .then(res => createPokemon(res))
    // })

    // Example: .race

    Promise.race(arrayOfPokemon).then(res => console.log(res)); //all it cares about is one finishing

    // Example: .all

    Promise.all(arrayOfPokemon).then(arrayOfResponses => {
        console.log("arrayOfResponses :", arrayOfResponses);

        arrayOfResponses.forEach((name) => {
            name.json().then((res) => createPokemon(res));
        })

    });


    // TODO: Demo DOM Interaction

    // Example: Show simple pokemon search

    $("#search").keyup((e) => {
        console.log("e.target.value:", e.target.value);
        if(e.key === "Enter") fetch(pokemonAPI + e.target.value)
            .then(res => res.json())
            .then(res => createPokemon(res))
            .catch(res => alert("No results!"));
    })


    // TODO/CLASS: Add disney results to page!
    const disneyAPI = 'https://api.disneyapi.dev/characters';
    //DOCS: "https://disneyapi.dev/docs";

    // ASK:
    // Can you call this api of disney characters and map each of these characters to
    // an unordered list. Attach that list to the page on the #disney id
    // Add the results to the disney div.
    // Include at least the character name in the list item.
    // const disneyAPI = 'https://api.disneyapi.dev/characters';
    //
    // const createCharacter = ({ name, imageUrl}) => {
    //     document.getElementById("disney").innerHTML +=
    //         `<li class="disney">
    //                 <h3>${name}</h3>
    //                 <img src="${imageUrl}">
    //             </li>`;
    // };
    //
    // fetch(disneyAPI).then(res => res.json()).then((res) => {
    //     document.getElementById("disney").innerHTML = '<ul>'
    //     res.data.forEach((char) => {
    //         createCharacter(char);
    //     });
    //     document.getElementById("disney").innerHTML += '</ul>'
    // });

</script>
</html>