Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
Examples referenced in async js blog post
// `series` Method Example
function eatFreeBread (bread, callback) {
setTimeout(function () {
console.log('Just ate some ' + bread + ' bread');
callback(null, {breadRating: 8});
}, 3000);
}
function eatAppetizers (apps, callback) {
setTimeout(function () {
console.log('Just ate these great appetizers ' + apps);
callback(null, {appRating: 9});
}, 3000);
}
function eatMainCourse (mainCourse, callback) {
setTimeout(function () {
console.log('Just ate the ' + mainCourse + ' main course');
callback(null, {mainCourseRating: 9});
}, 3000);
}
function eatDessert (dessert, callback) {
setTimeout(function () {
console.log('Just ate the ' + dessert + ' dessert');
callback(null, {dessertRating: 10});
}, 3000);
}
function handlePoorService () {
console.log('WE ARE DONE WITH THIS NON SENSE AND ARE LEAVING!')
}
function goOutToEatV1 (bread, apps, mainCourse, dessert, restaurantReviewCallback) {
eatFreeBread(bread, function (err, breadResult) {
if (err) {
handlePoorService();
restaurantReviewCallback(err);
} else {
eatAppetizers(apps, function (err, appsResult) {
if (err) {
handlePoorService();
restaurantReviewCallback(err);
} else {
eatMainCourse(mainCourse, function (err, mainCourseResult) {
if (err) {
handlePoorService();
restaurantReviewCallback(err);
} else {
eatDessert(dessert, function (err, dessertResult) {
if (err) {
handlePoorService();
restaurantReviewCallback(err);
} else {
restaurantReviewCallback(null, [
breadResult,
appsResult,
mainCourseResult,
dessertResult
]);
}
});
}
});
}
});
}
});
}
function goOutToEatV2 (bread, apps, mainCourse, dessert, restaurantReviewCallback) {
async.series([
function (callback) {
eatFreeBread(bread, callback);
},
function (callback) {
eatAppetizers(apps, callback);
},
function (callback) {
eatMainCourse(mainCourse, callback);
},
function (callback) {
eatDessert(dessert, callback);
},
], function (err, restaurantResults) {
if (err) {
handlePoorService();
}
restaurantReviewCallback(err, restaurantResults);
})
}
function goOutToEatV3 (bread, apps, mainCourse, dessert, restaurantReviewCallback) {
async.series([
_.curry(eatFreeBread)(bread),
_.curry(eatAppetizers)(apps),
_.curry(eatMainCourse)(mainCourse),
_.curry(eatDessert)(dessert),
], function (err, restaurantResults) {
if (err) {
handlePoorService();
}
restaurantReviewCallback(err, restaurantResults);
})
}
const bread = 'garlic';
const apps = ['rockefeller oysters', 'spinach and artichoke dip', 'bruschetta'];
const mainCourse = 'filet mignon';
const dessert = 'cheesecake';
const restaurantReviewCallback = function (err, results) { console.log('done with our review! ' + JSON.stringify(results)); };
// Uncomment to run different versions of the solution
// goOutToEatV1(bread, apps, mainCourse, dessert, restaurantReviewCallback);
// goOutToEatV2(bread, apps, mainCourse, dessert, restaurantReviewCallback);
// goOutToEatV3(bread, apps, mainCourse, dessert, restaurantReviewCallback);
// `each` Method Example
function sendEmail (emailAddress, email, callback) {
setTimeout(function () {
console.log('Sent the following email ' + email + ' to the following email address ' + emailAddress);
callback(null, {emailId: Math.floor(Math.random() * 10000)});
}, 3000);
}
function sendBatchOfEmailsV1 (emailAddresses, emailBody, callback) {
var emailHasFailed = false,
emailAddressIdx = 0,
emailIds = [];
while (!emailHasFailed && emailAddressIdx < emailAddresses.length) {
sendEmail(emailBody, emailAddresses[emailAddressIdx], function (err, result) {
if (err) {
emailHasFailed = true;
return callback(err);
} else {
emailIds.push(result.emailId);
}
if (emailIds.length === emailAddresses.length) {
callback(null, emailIds);
}
});
emailAddressIdx += 1;
}
}
function sendBatchOfEmailsV2 (emailAddresses, emailBody, callback) {
async.map(emailAddresses, function (emailAddress, asyncCallback) {
sendEmail(emailBody, emailAddress, asyncCallback);
}, callback);
}
function sendBatchOfEmailsV3 (emailAddresses, emailBody, batchCallback) {
async.map(emailAddresses, _.curry(sendEmail)(email), batchCallback);
}
const email = 'Async.js Hello World!';
const emailAddresses = [
'jdoe0@gmail.com',
'jdoe1@gmail.com',
'jdoe2@gmail.com',
'jdoe3@gmail.com',
'jdoe4@gmail.com',
'jdoe5@gmail.com',
'jdoe6@gmail.com',
'jdoe7@gmail.com',
'jdoe8@gmail.com',
'jdoe9@gmail.com'
];
const batchEmailCallback = function (err, emailIds) { console.log('Batch email send result = ' + JSON.stringify(emailIds)); };
// Uncomment to run different versions of the solution
// sendBatchOfEmailsV1(emailAddresses, email, batchEmailCallback);
// sendBatchOfEmailsV2(emailAddresses, email, batchEmailCallback);
// sendBatchOfEmailsV3(emailAddresses, email, batchEmailCallback);
// `waterfall` Method Example
function makeReservation (reservationDetails, callback) {
setTimeout(function () {
console.log('Made the following reservation ' + JSON.stringify(reservationDetails));
callback(null, Math.floor(Math.random() * 10000));
}, 3000);
}
function processCreditCardForReservation (creditCardDetails, reservationId, callback) {
setTimeout(function () {
console.log('Charged the following reservation ' + reservationId + ' to the following card ' + JSON.stringify(creditCardDetails));
callback(null, Math.floor(Math.random() * 10000));
}, 3000);
}
function emailAirlineTicketReceipt (emailAddress, receiptId, callback) {
setTimeout(function () {
console.log('Emailed a receipt for receipt ID ' + receiptId + ' to the following email address ' + emailAddress);
callback(null, Math.floor(Math.random() * 10000));
}, 3000);
}
function bookAirlineTicketV1 (reservationDetails, creditCardDetails, receiptEmailAddress, bookAirlineTicketCallback) {
makeReservation(reservationDetails, function (reservationErr, reservationId) {
if (reservationErr) {
bookAirlineTicketCallback(reservationErr);
} else {
processCreditCardForReservation(creditCardDetails, reservationId, function (creditCardProcessingError, receiptId) {
if (creditCardProcessingError) {
bookAirlineTicketCallback(creditCardProcessingError);
} else {
emailAirlineTicketReceipt(receiptEmailAddress, receiptId, function (emailError, emailId) {
bookAirlineTicketCallback(emailError);
});
}
});
}
});
}
function bookAirlineTicketV2 (reservationDetails, creditCardDetails, receiptEmailAddress, bookAirlineTicketCallback) {
async.waterfall([
function(callback) {
makeReservation(reservationDetails, callback);
},
function(reservationId, callback) {
processCreditCardForReservation(creditCardDetails, reservationId, callback);
},
function(receiptId, callback) {
emailAirlineTicketReceipt(receiptEmailAddress, receiptId, callback);
}
], bookAirlineTicketCallback);
}
function bookAirlineTicketV3 (reservationDetails, creditCardDetails, receiptEmailAddress, bookAirlineTicketCallback) {
async.waterfall([
_.curry(makeReservation)(reservationDetails),
_.curry(processCreditCardForReservation)(creditCardDetails),
_.curry(emailAirlineTicketReceipt)(receiptEmailAddress),
], bookAirlineTicketCallback);
}
const reservationDetails = { destination: 'Cancun, Mexico', departureDate: '05/05/2018', airline: 'Delta' };
const creditCardDetails = { number: '1111111111111111', cvv: '123', zipcode: '12345' };
const receiptEmailAddress = 'jdoe@gmail.com';
const bookingCallback = function (err, results) { console.log('Flight has been booked!'); };
// Uncomment to run different versions of the solution
// bookAirlineTicketV1(reservationDetails, creditCardDetails, receiptEmailAddress, bookingCallback);
// bookAirlineTicketV2(reservationDetails, creditCardDetails, receiptEmailAddress, bookingCallback);
// bookAirlineTicketV3(reservationDetails, creditCardDetails, receiptEmailAddress, bookingCallback);
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment