Firestore - Listen to specific field change?
How can I listen to a specific field change with firestore js sdk ?
In the documentation, they only seem to show how to listen for the whole document, if any of the "SF" field changes, it will trigger the callback.
db.collection("cities").doc("SF")
.onSnapshot(function(doc) {
console.log("Current data: ", doc && doc.data());
});
javascript firebase google-cloud-firestore
edited Dec 18 '17 at 1:52
Frank van Puffelen
242k29387414
asked Dec 17 '17 at 23:40
httpetehttpete
2,60832233
add a comment |
How can I listen to a specific field change with firestore js sdk ?
In the documentation, they only seem to show how to listen for the whole document, if any of the "SF" field changes, it will trigger the callback.
db.collection("cities").doc("SF")
.onSnapshot(function(doc) {
console.log("Current data: ", doc && doc.data());
});
javascript firebase google-cloud-firestore
edited Dec 18 '17 at 1:52
Frank van Puffelen
242k29387414
asked Dec 17 '17 at 23:40
httpetehttpete
2,60832233
add a comment |
How can I listen to a specific field change with firestore js sdk ?
In the documentation, they only seem to show how to listen for the whole document, if any of the "SF" field changes, it will trigger the callback.
db.collection("cities").doc("SF")
.onSnapshot(function(doc) {
console.log("Current data: ", doc && doc.data());
});
javascript firebase google-cloud-firestore
edited Dec 18 '17 at 1:52
Frank van Puffelen
242k29387414
asked Dec 17 '17 at 23:40
httpetehttpete
2,60832233
How can I listen to a specific field change with firestore js sdk ?
In the documentation, they only seem to show how to listen for the whole document, if any of the "SF" field changes, it will trigger the callback.
db.collection("cities").doc("SF")
.onSnapshot(function(doc) {
console.log("Current data: ", doc && doc.data());
});
javascript firebase google-cloud-firestore
javascript firebase google-cloud-firestore
edited Dec 18 '17 at 1:52
Frank van Puffelen
242k29387414
asked Dec 17 '17 at 23:40
httpetehttpete
2,60832233
edited Dec 18 '17 at 1:52
Frank van Puffelen
242k29387414
asked Dec 17 '17 at 23:40
httpetehttpete
2,60832233
edited Dec 18 '17 at 1:52
Frank van Puffelen
242k29387414
edited Dec 18 '17 at 1:52
Frank van Puffelen
242k29387414
edited Dec 18 '17 at 1:52
Frank van Puffelen
242k29387414
242k29387414
asked Dec 17 '17 at 23:40
httpetehttpete
2,60832233
asked Dec 17 '17 at 23:40
httpetehttpete
2,60832233
asked Dec 17 '17 at 23:40
httpetehttpete
2,60832233
2,60832233
add a comment |
add a comment |
3 Answers
3
active
oldest
votes
You can't. All operations in Firestore are on an entire document.
This is also true for Cloud Functions Firestore triggers (you can only receive an entire document that's changed in some way).
If you need to narrow the scope of some data to retrieve from a document, place that in a document within a subcollection, and query for that document individually.
answered Dec 17 '17 at 23:51
Doug StevensonDoug Stevenson
81.6k997115
3
Isn't that a big drawback compared to the firebase realtime database solution ?
– httpete
Dec 20 '17 at 22:19
1
Yes, this is known difference in behavior, and been discussed in various forums. If all you want to do is locate an existing key in the database and listen to changes, that's much easier in RTDB. In fact, there are a bunch of other known advantages (currently), documented at the end of this blog: firebase.googleblog.com/2017/10/…
– Doug Stevenson
Dec 20 '17 at 22:29
1
Does anyone know if they have plans to make this a feature? Especially with Cloud functions.firestore.document().field('myField/subFieldEtc').onUpdate()?
– Jonathan002
Jan 25 at 11:11
add a comment |
Just in case you want to ignore events in some fields, you can do something like:
export const yourCloudFunction = functions.firestore
.document('/your-path')
.onUpdate(
field('foo', 'REMOVED', (change, context) => {
console.log('Will get here only if foo was removed');
// ... Your implementation here
}),
);
I created a gist of the field function here. Remember, it is not avoiding your function to run if changes happen in other fields, it will just not handle that over to you and return a resolved promise instead.
answered Nov 26 '18 at 1:53
ChristianChristian
97112
add a comment |
Listen for the document, then set a conditional on the field you're interesting in:
firebase.firestore().collection('Dictionaries').doc('Spanish').collection('Words').doc(word).collection('Pronunciations').doc('Castilian-female-IBM').onSnapshot(function(snapshot) {
if (snapshot.data().audioFiles) { // eliminates an error message
if (snapshot.data().audioFiles.length === 2) {
audioFilesReady++;
if (audioFilesReady === 3) {
$scope.showNextWord();
}
}
}
}, function(error) {
console.error(error);
});
I'm listening for a document for a voice (Castilian-female-IBM), which contains an array of audio files, in webm and mp3 formats. When both of those audio files have come back asynchronously then snapshot.data().audioFiles.length === 2. This increments a conditional. When two more voices come back (Castilian-male-IBM and Latin_American-female-IBM) then audioFilesReady === 3 and the next function $scope.showNextWord() fires.
answered Feb 23 at 18:53
Thomas David KehoeThomas David Kehoe
2,25611437
add a comment |
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3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
You can't. All operations in Firestore are on an entire document.
This is also true for Cloud Functions Firestore triggers (you can only receive an entire document that's changed in some way).
If you need to narrow the scope of some data to retrieve from a document, place that in a document within a subcollection, and query for that document individually.
answered Dec 17 '17 at 23:51
Doug StevensonDoug Stevenson
81.6k997115
3
Isn't that a big drawback compared to the firebase realtime database solution ?
– httpete
Dec 20 '17 at 22:19
1
Yes, this is known difference in behavior, and been discussed in various forums. If all you want to do is locate an existing key in the database and listen to changes, that's much easier in RTDB. In fact, there are a bunch of other known advantages (currently), documented at the end of this blog: firebase.googleblog.com/2017/10/…
– Doug Stevenson
Dec 20 '17 at 22:29
1
Does anyone know if they have plans to make this a feature? Especially with Cloud functions.firestore.document().field('myField/subFieldEtc').onUpdate()?
– Jonathan002
Jan 25 at 11:11
add a comment |
You can't. All operations in Firestore are on an entire document.
This is also true for Cloud Functions Firestore triggers (you can only receive an entire document that's changed in some way).
If you need to narrow the scope of some data to retrieve from a document, place that in a document within a subcollection, and query for that document individually.
answered Dec 17 '17 at 23:51
Doug StevensonDoug Stevenson
81.6k997115
3
Isn't that a big drawback compared to the firebase realtime database solution ?
– httpete
Dec 20 '17 at 22:19
1
Yes, this is known difference in behavior, and been discussed in various forums. If all you want to do is locate an existing key in the database and listen to changes, that's much easier in RTDB. In fact, there are a bunch of other known advantages (currently), documented at the end of this blog: firebase.googleblog.com/2017/10/…
– Doug Stevenson
Dec 20 '17 at 22:29
1
Does anyone know if they have plans to make this a feature? Especially with Cloud functions.firestore.document().field('myField/subFieldEtc').onUpdate()?
– Jonathan002
Jan 25 at 11:11
add a comment |
You can't. All operations in Firestore are on an entire document.
This is also true for Cloud Functions Firestore triggers (you can only receive an entire document that's changed in some way).
If you need to narrow the scope of some data to retrieve from a document, place that in a document within a subcollection, and query for that document individually.
answered Dec 17 '17 at 23:51
Doug StevensonDoug Stevenson
81.6k997115
You can't. All operations in Firestore are on an entire document.
This is also true for Cloud Functions Firestore triggers (you can only receive an entire document that's changed in some way).
If you need to narrow the scope of some data to retrieve from a document, place that in a document within a subcollection, and query for that document individually.
answered Dec 17 '17 at 23:51
Doug StevensonDoug Stevenson
81.6k997115
answered Dec 17 '17 at 23:51
Doug StevensonDoug Stevenson
81.6k997115
answered Dec 17 '17 at 23:51
Doug StevensonDoug Stevenson
81.6k997115
answered Dec 17 '17 at 23:51
Doug StevensonDoug Stevenson
81.6k997115
81.6k997115
3
Isn't that a big drawback compared to the firebase realtime database solution ?
– httpete
Dec 20 '17 at 22:19
1
Yes, this is known difference in behavior, and been discussed in various forums. If all you want to do is locate an existing key in the database and listen to changes, that's much easier in RTDB. In fact, there are a bunch of other known advantages (currently), documented at the end of this blog: firebase.googleblog.com/2017/10/…
– Doug Stevenson
Dec 20 '17 at 22:29
1
Does anyone know if they have plans to make this a feature? Especially with Cloud functions.firestore.document().field('myField/subFieldEtc').onUpdate()?
– Jonathan002
Jan 25 at 11:11
add a comment |
3
Isn't that a big drawback compared to the firebase realtime database solution ?
– httpete
Dec 20 '17 at 22:19
1
Yes, this is known difference in behavior, and been discussed in various forums. If all you want to do is locate an existing key in the database and listen to changes, that's much easier in RTDB. In fact, there are a bunch of other known advantages (currently), documented at the end of this blog: firebase.googleblog.com/2017/10/…
– Doug Stevenson
Dec 20 '17 at 22:29
1
Does anyone know if they have plans to make this a feature? Especially with Cloud functions.firestore.document().field('myField/subFieldEtc').onUpdate()?
– Jonathan002
Jan 25 at 11:11
3
3
Isn't that a big drawback compared to the firebase realtime database solution ?
– httpete
Dec 20 '17 at 22:19
Isn't that a big drawback compared to the firebase realtime database solution ?
– httpete
Dec 20 '17 at 22:19
1
1
Yes, this is known difference in behavior, and been discussed in various forums. If all you want to do is locate an existing key in the database and listen to changes, that's much easier in RTDB. In fact, there are a bunch of other known advantages (currently), documented at the end of this blog: firebase.googleblog.com/2017/10/…
– Doug Stevenson
Dec 20 '17 at 22:29
Yes, this is known difference in behavior, and been discussed in various forums. If all you want to do is locate an existing key in the database and listen to changes, that's much easier in RTDB. In fact, there are a bunch of other known advantages (currently), documented at the end of this blog: firebase.googleblog.com/2017/10/…
– Doug Stevenson
Dec 20 '17 at 22:29
1
1
Does anyone know if they have plans to make this a feature? Especially with Cloud functions.firestore.document().field('myField/subFieldEtc').onUpdate()?
– Jonathan002
Jan 25 at 11:11
Does anyone know if they have plans to make this a feature? Especially with Cloud functions.firestore.document().field('myField/subFieldEtc').onUpdate()?
– Jonathan002
Jan 25 at 11:11
add a comment |
Just in case you want to ignore events in some fields, you can do something like:
export const yourCloudFunction = functions.firestore
.document('/your-path')
.onUpdate(
field('foo', 'REMOVED', (change, context) => {
console.log('Will get here only if foo was removed');
// ... Your implementation here
}),
);
I created a gist of the field function here. Remember, it is not avoiding your function to run if changes happen in other fields, it will just not handle that over to you and return a resolved promise instead.
answered Nov 26 '18 at 1:53
ChristianChristian
97112
add a comment |
Just in case you want to ignore events in some fields, you can do something like:
export const yourCloudFunction = functions.firestore
.document('/your-path')
.onUpdate(
field('foo', 'REMOVED', (change, context) => {
console.log('Will get here only if foo was removed');
// ... Your implementation here
}),
);
I created a gist of the field function here. Remember, it is not avoiding your function to run if changes happen in other fields, it will just not handle that over to you and return a resolved promise instead.
answered Nov 26 '18 at 1:53
ChristianChristian
97112
add a comment |
Just in case you want to ignore events in some fields, you can do something like:
export const yourCloudFunction = functions.firestore
.document('/your-path')
.onUpdate(
field('foo', 'REMOVED', (change, context) => {
console.log('Will get here only if foo was removed');
// ... Your implementation here
}),
);
I created a gist of the field function here. Remember, it is not avoiding your function to run if changes happen in other fields, it will just not handle that over to you and return a resolved promise instead.
answered Nov 26 '18 at 1:53
ChristianChristian
97112
Just in case you want to ignore events in some fields, you can do something like:
export const yourCloudFunction = functions.firestore
.document('/your-path')
.onUpdate(
field('foo', 'REMOVED', (change, context) => {
console.log('Will get here only if foo was removed');
// ... Your implementation here
}),
);
I created a gist of the field function here. Remember, it is not avoiding your function to run if changes happen in other fields, it will just not handle that over to you and return a resolved promise instead.
answered Nov 26 '18 at 1:53
ChristianChristian
97112
answered Nov 26 '18 at 1:53
ChristianChristian
97112
answered Nov 26 '18 at 1:53
ChristianChristian
97112
answered Nov 26 '18 at 1:53
ChristianChristian
97112
97112
add a comment |
add a comment |
Listen for the document, then set a conditional on the field you're interesting in:
firebase.firestore().collection('Dictionaries').doc('Spanish').collection('Words').doc(word).collection('Pronunciations').doc('Castilian-female-IBM').onSnapshot(function(snapshot) {
if (snapshot.data().audioFiles) { // eliminates an error message
if (snapshot.data().audioFiles.length === 2) {
audioFilesReady++;
if (audioFilesReady === 3) {
$scope.showNextWord();
}
}
}
}, function(error) {
console.error(error);
});
I'm listening for a document for a voice (Castilian-female-IBM), which contains an array of audio files, in webm and mp3 formats. When both of those audio files have come back asynchronously then snapshot.data().audioFiles.length === 2. This increments a conditional. When two more voices come back (Castilian-male-IBM and Latin_American-female-IBM) then audioFilesReady === 3 and the next function $scope.showNextWord() fires.
answered Feb 23 at 18:53
Thomas David KehoeThomas David Kehoe
2,25611437
add a comment |
Listen for the document, then set a conditional on the field you're interesting in:
firebase.firestore().collection('Dictionaries').doc('Spanish').collection('Words').doc(word).collection('Pronunciations').doc('Castilian-female-IBM').onSnapshot(function(snapshot) {
if (snapshot.data().audioFiles) { // eliminates an error message
if (snapshot.data().audioFiles.length === 2) {
audioFilesReady++;
if (audioFilesReady === 3) {
$scope.showNextWord();
}
}
}
}, function(error) {
console.error(error);
});
I'm listening for a document for a voice (Castilian-female-IBM), which contains an array of audio files, in webm and mp3 formats. When both of those audio files have come back asynchronously then snapshot.data().audioFiles.length === 2. This increments a conditional. When two more voices come back (Castilian-male-IBM and Latin_American-female-IBM) then audioFilesReady === 3 and the next function $scope.showNextWord() fires.
answered Feb 23 at 18:53
Thomas David KehoeThomas David Kehoe
2,25611437
add a comment |
Listen for the document, then set a conditional on the field you're interesting in:
firebase.firestore().collection('Dictionaries').doc('Spanish').collection('Words').doc(word).collection('Pronunciations').doc('Castilian-female-IBM').onSnapshot(function(snapshot) {
if (snapshot.data().audioFiles) { // eliminates an error message
if (snapshot.data().audioFiles.length === 2) {
audioFilesReady++;
if (audioFilesReady === 3) {
$scope.showNextWord();
}
}
}
}, function(error) {
console.error(error);
});
I'm listening for a document for a voice (Castilian-female-IBM), which contains an array of audio files, in webm and mp3 formats. When both of those audio files have come back asynchronously then snapshot.data().audioFiles.length === 2. This increments a conditional. When two more voices come back (Castilian-male-IBM and Latin_American-female-IBM) then audioFilesReady === 3 and the next function $scope.showNextWord() fires.
answered Feb 23 at 18:53
Thomas David KehoeThomas David Kehoe
2,25611437
Listen for the document, then set a conditional on the field you're interesting in:
firebase.firestore().collection('Dictionaries').doc('Spanish').collection('Words').doc(word).collection('Pronunciations').doc('Castilian-female-IBM').onSnapshot(function(snapshot) {
if (snapshot.data().audioFiles) { // eliminates an error message
if (snapshot.data().audioFiles.length === 2) {
audioFilesReady++;
if (audioFilesReady === 3) {
$scope.showNextWord();
}
}
}
}, function(error) {
console.error(error);
});
I'm listening for a document for a voice (Castilian-female-IBM), which contains an array of audio files, in webm and mp3 formats. When both of those audio files have come back asynchronously then snapshot.data().audioFiles.length === 2. This increments a conditional. When two more voices come back (Castilian-male-IBM and Latin_American-female-IBM) then audioFilesReady === 3 and the next function $scope.showNextWord() fires.
answered Feb 23 at 18:53
Thomas David KehoeThomas David Kehoe
2,25611437
answered Feb 23 at 18:53
Thomas David KehoeThomas David Kehoe
2,25611437
answered Feb 23 at 18:53
Thomas David KehoeThomas David Kehoe
2,25611437
answered Feb 23 at 18:53
Thomas David KehoeThomas David Kehoe
2,25611437
2,25611437
add a comment |
add a comment |
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