js-102/030_functional_flow_control/030_000_inversion_of_control.js

JS-102 helps you learn JavaScript (the right way) so that you can confidently use higher-level libraries and frameworks. — Let’s reveal the magic!

/*
 *                    the devil is in the details
 *      .--. __--__  (`-')    .--.  .----.  .----.
 *      | ,|/    _ / ( OO).->/_  | /  ..  \\_,-.  |
 *      |(_|\_..`--.(,------. |  ||  /  \  .  .' .'
 * ,--. |  |.-._)   \`------' |  |'  \  /  '.'  /_
 * |  '-'  /\       /         |  | \  `'  /|      |
 *  `-----'  `-----'          `--'  `---'' `------'
 *
 * This project is a part of the “Byte-Sized JavaScript” videocasts.
 *
 * You can watch “Byte-Sized JavaScript” at: https://bytesized.tv/
 *
 * MIT Licensed — See LICENSE.md
 *
 * Send your comments, suggestions, and feedback to me@volkan.io
 */

/* eslint-ignore */

// ## Note
//
// The code you see here is just a pseudocode to show different programming
// paradigms. When you try to run it, it will not run.
//
// Watch (Episode 18)* for the screncast that covers this topic.
//
// * https://bytesized.tv/episodes/18/byte-sized-javascript-episode-18-all-the-promises-we-made/FiTXJQWilDM

//
// This is how you bake a cake sequentially:
//

const bakeCheesecake = () => {
    const ingredients = fetchIngredients();
    const oven = locateOven();

    oven.heat( '325F' );

    waitUntil( oven.ready );

    const batter = join( ingredients.grahamCrumbs, ingredients.sugar.take( '3tbsp' ) );

    saucepan.spread( batter );

    mixture = beat( ingredients.creamCheese, ingredients.vanilla, ingredients.sugar.take( '1cup' ) );

    waitUntil( mixture.blended );

    oven.put( mixture );
    oven.bake( '55m' );

    waitUntil( oven.timer.remaining.equals( 0 ) );

    console.log( 'Your cheesecake is ready. Yum!' );
}

//
// This is how you bake a cake using continuation-passing style:
//

const bakeCheesecakeCps = ( cb ) => {
    const oven = locateOven();

    fetchIngredients( err, ( ingredients ) => {
        if ( err ) { cb( 'Error' ); return; }

        heat( oven, '325f', ( err ) => {
            if ( err ) { cb( 'Error'); return; }

            const batter = join( ingredients.grahamCrumbs, ingredients.sugar.take( '3tbsp' ) );

            spread( saucepan, batter, ( err ) => {
                if ( err ) { cb( 'Error' ); return; }

                beat(
                    ingredients.creamCheese, ingredients.vanilla, ingredients.sugar.take( '1cup' ),

                    ( err, mixture ) => {
                        if ( err ) { cb( 'Error' ); return; }

                        bake( oven, mixture, '55m', ( err ) =>  {
                            if ( err ) { cb( 'Error' ); return; }

                            cb( 'Your cheesecake is ready. Yum!' );
                        } );
                    }
                );
            } );
        } );
    } );
}

//
// This is how you bake a cake using promises:
//

const bakePromise = () => {
    const oven = locateOven();

    fetchIngredients()
        .then(
            ( ingredients ) =>
            spread( saucepan, join( ingredients.grahamCrumbs, ingredients.sugar.take( '3tbsp' ) ) )
        )
        .then( ( mixture ) => bake( oven, mixture, '55m' ) )
        .then( () => console.log( 'Your cheesecake is ready. Yum!' ) )
        .catch( () => console.error( 'Oh poop!' ) );
}

//
// This is how you bake a cake using async/await:
//

const bakeAwait = () => {
    try {
        const oven = locateOven();

        const ingredients = await fetchIngredients();

        const mixture = await = spread(
            saucepan,
            join( ingredients.grahamCrumbs, ingredients.sugar.take( '3tbsp' ) )
        );

        await bake( oven, mixture, '55m' );

        console.log( 'Your cheesecake is ready. Yum!' );
    } catch ( err ) {
        console.err( 'Oh poop!' );
    }
}