this might seem a silly question but I am a newbie in this topic. I am working on promises on node js. And I want to pass parameter to a promise function. However I could not figure it out.
someModule.someFunction.then(username, password,function(uid) {
/*stuff */
}
and the function is something like
var someFunction = new Promise(username, password, function(resolve, reject) {
/*stuff using username, password*/
if ( /* everything turned out fine */ ) {
resolve("Stuff worked!");
} else {
reject(Error("It broke"));
}
});
This question is related to
javascript
node.js
promise
parameter-passing
es6-promise
Even shorter
var foo = (user, pass) =>
new Promise((resolve, reject) => {
if (/* condition */) {
resolve("Fine");
} else {
reject("Error message");
}
});
foo(user, pass).then(result => {
/* process */
});
Try this:
function someFunction(username, password) {
return new Promise((resolve, reject) => {
// Do something with the params username and password...
if ( /* everything turned out fine */ ) {
resolve("Stuff worked!");
} else {
reject(Error("It didn't work!"));
}
});
}
someFunction(username, password)
.then((result) => {
// Do something...
})
.catch((err) => {
// Handle the error...
});
You can use .bind() to pass the param(this) to the function.
var someFunction =function(resolve, reject) {
/* get username, password*/
var username=this.username;
var password=this.password;
if ( /* everything turned out fine */ ) {
resolve("Stuff worked!");
} else {
reject(Error("It broke"));
}
}
var promise=new Promise(someFunction.bind({username:"your username",password:"your password"}));
Another way(Must Try):
var promise1 = new Promise(function(resolve, reject) {_x000D_
resolve('Success!');_x000D_
});_x000D_
var extraData = 'ImExtraData';_x000D_
promise1.then(function(value) {_x000D_
console.log(value, extraData);_x000D_
// expected output: "Success!" "ImExtraData"_x000D_
}, extraData);
_x000D_
Source: Stackoverflow.com