async.js (yes, another one!)
This is a light-weight approximate implementation of ES7's async-await pattern.
Install it
You can npm install it.
npm install marcosc-async --savePlay with it!
You can play with the async API through gh-pages.
API
Once you import it (using either a script tag or require), there will be an "async" function you can use on the global object.
The async function takes generator, and returns a function that you can call as needed. It returns a promise.
const doAsyncThing = async(function*(args) {
var result = yield Promise.resolve(1);
return result;
});
doAsyncThing()
.then(value => console.log(value)); // 1Examples
You can create simple async functions like so:
const async = require("marcosc-async");
var doSomethingAsync = async(function*(){
return yield Promise.resolve("hi")
});
doSomethingAsync()
.then(value => console.log(value)); // "hi"Simple example for downloading a list of URLs.
const urls = ["/a", "/b"];
const doAsyncThing = async(function*(listOfURLs) {
let responses = [];
for (let url of listOfURLs) {
responses.push(yield fetch(url));
}
return yield Promise.all(responses.map(res => res.toJSON()));
});
doAsyncThing(urls)
.then(doSomethingElse)
.catch(err => console.error(error));It allows for simple creation of async function and "tasks". For example:
const async = require("marcosc-async");
const myThinger = {
doAsynThing: async(function*(url) {
const response = yield fetch(url);
const text = yield response.text();
return process(result);
}),
};And task-like things can be created as follows:
const async = require("marcosc-async");
// Run immediately
const myTask = async.task(function*(url) {
const response = yield fetch(url);
const text = yield response.text();
return process(result);
}).then(doSomethingElse);
Binding this
You can also correctly bind this like so:
const async = require("marcosc-async");
const myThinger = {
someValue: "value",
asyncTaskA(...args) {
return async(function*() {
return yield this.asyncTaskB(...args)
}, this);
},
asyncTaskB(...args) {
async(function*() {
return this.value;
}, this);
},
};
