Calling (and catching) multiple promises
0
I am trying to run below code (modified from this link):
let cnt = 1;
var prom = () => new Promise(
function (resolve, reject) {
try {
console.log('enter promise ' + cnt);
if (Math.random() < 0.5) throw new Error('error in promise ' + cnt);
resolve('done in promise ' + cnt);
}
catch (e) {
reject(e);
}
finally{
cnt++;
}
}
);
prom()
.then(prom())
.then(function (fulfilled) {
console.log('all done: ' + fulfilled);
})
.catch(function (error) {
console.log(error.message);
});
Basically I am trying to achieve a catch-all behaviour, i.e. if either promise fails, catch and stop processing. However can't achieve. What am I missing?
node.js promise
asked Nov 21 '18 at 22:47
paul simmonspaul simmons
2,503104672
add a comment |
0
I am trying to run below code (modified from this link):
let cnt = 1;
var prom = () => new Promise(
function (resolve, reject) {
try {
console.log('enter promise ' + cnt);
if (Math.random() < 0.5) throw new Error('error in promise ' + cnt);
resolve('done in promise ' + cnt);
}
catch (e) {
reject(e);
}
finally{
cnt++;
}
}
);
prom()
.then(prom())
.then(function (fulfilled) {
console.log('all done: ' + fulfilled);
})
.catch(function (error) {
console.log(error.message);
});
Basically I am trying to achieve a catch-all behaviour, i.e. if either promise fails, catch and stop processing. However can't achieve. What am I missing?
node.js promise
asked Nov 21 '18 at 22:47
paul simmonspaul simmons
2,503104672
What is happening? Are you getting an error? What error?
– iagowp
Nov 21 '18 at 22:54
Do not pass a promise tothen(). Pass a callback function instead, e.g..then(prom).
– Bergi
Nov 21 '18 at 22:57
this looks like the issue; can you make it an answer?
– paul simmons
Nov 21 '18 at 22:58
Which example exactly from the linked page did you use, and what and why did you modify?
– Bergi
Nov 21 '18 at 22:59
add a comment |
0
0
0
I am trying to run below code (modified from this link):
let cnt = 1;
var prom = () => new Promise(
function (resolve, reject) {
try {
console.log('enter promise ' + cnt);
if (Math.random() < 0.5) throw new Error('error in promise ' + cnt);
resolve('done in promise ' + cnt);
}
catch (e) {
reject(e);
}
finally{
cnt++;
}
}
);
prom()
.then(prom())
.then(function (fulfilled) {
console.log('all done: ' + fulfilled);
})
.catch(function (error) {
console.log(error.message);
});
Basically I am trying to achieve a catch-all behaviour, i.e. if either promise fails, catch and stop processing. However can't achieve. What am I missing?
node.js promise
asked Nov 21 '18 at 22:47
paul simmonspaul simmons
2,503104672
I am trying to run below code (modified from this link):
let cnt = 1;
var prom = () => new Promise(
function (resolve, reject) {
try {
console.log('enter promise ' + cnt);
if (Math.random() < 0.5) throw new Error('error in promise ' + cnt);
resolve('done in promise ' + cnt);
}
catch (e) {
reject(e);
}
finally{
cnt++;
}
}
);
prom()
.then(prom())
.then(function (fulfilled) {
console.log('all done: ' + fulfilled);
})
.catch(function (error) {
console.log(error.message);
});
Basically I am trying to achieve a catch-all behaviour, i.e. if either promise fails, catch and stop processing. However can't achieve. What am I missing?
node.js promise
node.js promise
asked Nov 21 '18 at 22:47
paul simmonspaul simmons
2,503104672
asked Nov 21 '18 at 22:47
paul simmonspaul simmons
2,503104672
asked Nov 21 '18 at 22:47
paul simmonspaul simmons
2,503104672
asked Nov 21 '18 at 22:47
paul simmonspaul simmons
2,503104672
asked Nov 21 '18 at 22:47
paul simmonspaul simmons
2,503104672
2,503104672
What is happening? Are you getting an error? What error?
– iagowp
Nov 21 '18 at 22:54
Do not pass a promise tothen(). Pass a callback function instead, e.g..then(prom).
– Bergi
Nov 21 '18 at 22:57
this looks like the issue; can you make it an answer?
– paul simmons
Nov 21 '18 at 22:58
Which example exactly from the linked page did you use, and what and why did you modify?
– Bergi
Nov 21 '18 at 22:59
add a comment |
What is happening? Are you getting an error? What error?
– iagowp
Nov 21 '18 at 22:54
Do not pass a promise tothen(). Pass a callback function instead, e.g..then(prom).
– Bergi
Nov 21 '18 at 22:57
this looks like the issue; can you make it an answer?
– paul simmons
Nov 21 '18 at 22:58
Which example exactly from the linked page did you use, and what and why did you modify?
– Bergi
Nov 21 '18 at 22:59
What is happening? Are you getting an error? What error?
– iagowp
Nov 21 '18 at 22:54
What is happening? Are you getting an error? What error?
– iagowp
Nov 21 '18 at 22:54
Do not pass a promise to
then(). Pass a callback function instead, e.g. .then(prom).– Bergi
Nov 21 '18 at 22:57
Do not pass a promise to
then(). Pass a callback function instead, e.g. .then(prom).– Bergi
Nov 21 '18 at 22:57
this looks like the issue; can you make it an answer?
– paul simmons
Nov 21 '18 at 22:58
this looks like the issue; can you make it an answer?
– paul simmons
Nov 21 '18 at 22:58
Which example exactly from the linked page did you use, and what and why did you modify?
– Bergi
Nov 21 '18 at 22:59
Which example exactly from the linked page did you use, and what and why did you modify?
– Bergi
Nov 21 '18 at 22:59
add a comment |
2 Answers
2
active
oldest
votes
0
.then() takes a callback as an argument and you gave it the returned Promise itself.
Use .then(prom) instead.
answered Nov 21 '18 at 23:04
Sebastian SpeitelSebastian Speitel
4,5682627
add a comment |
0
Use Promise.all
return Promise.all([
prom(),
prom()
])
.then(([fullfilled1, fulfilled2]) => {
console.log('all done: ' + fulfilled1 + ' ' + fulfilled2);
})
.catch(err => {
console.log(error.message);
});
If one fails, everyone fails.
answered Nov 21 '18 at 23:37
dvsoukupdvsoukup
1,062923
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
0
.then() takes a callback as an argument and you gave it the returned Promise itself.
Use .then(prom) instead.
answered Nov 21 '18 at 23:04
Sebastian SpeitelSebastian Speitel
4,5682627
add a comment |
0
.then() takes a callback as an argument and you gave it the returned Promise itself.
Use .then(prom) instead.
answered Nov 21 '18 at 23:04
Sebastian SpeitelSebastian Speitel
4,5682627
add a comment |
0
0
0
.then() takes a callback as an argument and you gave it the returned Promise itself.
Use .then(prom) instead.
answered Nov 21 '18 at 23:04
Sebastian SpeitelSebastian Speitel
4,5682627
.then() takes a callback as an argument and you gave it the returned Promise itself.
Use .then(prom) instead.
answered Nov 21 '18 at 23:04
Sebastian SpeitelSebastian Speitel
4,5682627
answered Nov 21 '18 at 23:04
Sebastian SpeitelSebastian Speitel
4,5682627
answered Nov 21 '18 at 23:04
Sebastian SpeitelSebastian Speitel
4,5682627
answered Nov 21 '18 at 23:04
Sebastian SpeitelSebastian Speitel
4,5682627
4,5682627
add a comment |
add a comment |
0
Use Promise.all
return Promise.all([
prom(),
prom()
])
.then(([fullfilled1, fulfilled2]) => {
console.log('all done: ' + fulfilled1 + ' ' + fulfilled2);
})
.catch(err => {
console.log(error.message);
});
If one fails, everyone fails.
answered Nov 21 '18 at 23:37
dvsoukupdvsoukup
1,062923
add a comment |
0
Use Promise.all
return Promise.all([
prom(),
prom()
])
.then(([fullfilled1, fulfilled2]) => {
console.log('all done: ' + fulfilled1 + ' ' + fulfilled2);
})
.catch(err => {
console.log(error.message);
});
If one fails, everyone fails.
answered Nov 21 '18 at 23:37
dvsoukupdvsoukup
1,062923
add a comment |
0
0
0
Use Promise.all
return Promise.all([
prom(),
prom()
])
.then(([fullfilled1, fulfilled2]) => {
console.log('all done: ' + fulfilled1 + ' ' + fulfilled2);
})
.catch(err => {
console.log(error.message);
});
If one fails, everyone fails.
answered Nov 21 '18 at 23:37
dvsoukupdvsoukup
1,062923
Use Promise.all
return Promise.all([
prom(),
prom()
])
.then(([fullfilled1, fulfilled2]) => {
console.log('all done: ' + fulfilled1 + ' ' + fulfilled2);
})
.catch(err => {
console.log(error.message);
});
If one fails, everyone fails.
answered Nov 21 '18 at 23:37
dvsoukupdvsoukup
1,062923
answered Nov 21 '18 at 23:37
dvsoukupdvsoukup
1,062923
answered Nov 21 '18 at 23:37
dvsoukupdvsoukup
1,062923
answered Nov 21 '18 at 23:37
dvsoukupdvsoukup
1,062923
1,062923
add a comment |
add a comment |
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What is happening? Are you getting an error? What error?
– iagowp
Nov 21 '18 at 22:54
Do not pass a promise to
then(). Pass a callback function instead, e.g..then(prom).– Bergi
Nov 21 '18 at 22:57
this looks like the issue; can you make it an answer?
– paul simmons
Nov 21 '18 at 22:58
Which example exactly from the linked page did you use, and what and why did you modify?
– Bergi
Nov 21 '18 at 22:59