Mixing
Migrating from CloudKit to Firestore (change token implementation)
I want to migrate my iOS app from CloudKit to Firestore. Most of the architectural changes are simple, but there is one caveat that I do not understand how to overcome.
In CloudKit, I can save a change token on the client and pass it to CloudKit functions when fetching or saving data. During fetch, it ensures that I receive only those updates, which I did not previously receive. During save, unless my change token corresponds to the latest available one, the operation fails until I perform a fetch first. In my case, this design is ideal.
Unfortunately, it seems like such functionality is not available out of the box in Firestore. For example, when attaching a listener to document snapshot, there is no way to tell Firestore "Here is a token X corresponding to the last update which I have and I want to receive all updates following it".
I could theoretically implement the change token functionality myself using cloud functions. The issue, however, is that two devices can try to perform an update simultaneously and I would need to find a way to ensure that one of these updates is executed in full before the other one starts (so that one of them fails with "invalid change token").
It sounds to me like a common design pattern, but I am struggling to find any ideas as to how to implement it correctly in Firebase.
Hence, I would like to ask you for suggestions on how I should proceed with migrating the "change token" functionality from CloudKit to Firestore.
Note, I am making my first steps in backend development, so my terminology is far from perfect.
firebase synchronization google-cloud-firestore google-cloud-functions cloudkit
asked Jan 1 at 18:36
Andriy GordiychukAndriy Gordiychuk
4,23511444
add a comment |
I want to migrate my iOS app from CloudKit to Firestore. Most of the architectural changes are simple, but there is one caveat that I do not understand how to overcome.
In CloudKit, I can save a change token on the client and pass it to CloudKit functions when fetching or saving data. During fetch, it ensures that I receive only those updates, which I did not previously receive. During save, unless my change token corresponds to the latest available one, the operation fails until I perform a fetch first. In my case, this design is ideal.
Unfortunately, it seems like such functionality is not available out of the box in Firestore. For example, when attaching a listener to document snapshot, there is no way to tell Firestore "Here is a token X corresponding to the last update which I have and I want to receive all updates following it".
I could theoretically implement the change token functionality myself using cloud functions. The issue, however, is that two devices can try to perform an update simultaneously and I would need to find a way to ensure that one of these updates is executed in full before the other one starts (so that one of them fails with "invalid change token").
It sounds to me like a common design pattern, but I am struggling to find any ideas as to how to implement it correctly in Firebase.
Hence, I would like to ask you for suggestions on how I should proceed with migrating the "change token" functionality from CloudKit to Firestore.
Note, I am making my first steps in backend development, so my terminology is far from perfect.
firebase synchronization google-cloud-firestore google-cloud-functions cloudkit
asked Jan 1 at 18:36
Andriy GordiychukAndriy Gordiychuk
4,23511444
add a comment |
I want to migrate my iOS app from CloudKit to Firestore. Most of the architectural changes are simple, but there is one caveat that I do not understand how to overcome.
In CloudKit, I can save a change token on the client and pass it to CloudKit functions when fetching or saving data. During fetch, it ensures that I receive only those updates, which I did not previously receive. During save, unless my change token corresponds to the latest available one, the operation fails until I perform a fetch first. In my case, this design is ideal.
Unfortunately, it seems like such functionality is not available out of the box in Firestore. For example, when attaching a listener to document snapshot, there is no way to tell Firestore "Here is a token X corresponding to the last update which I have and I want to receive all updates following it".
I could theoretically implement the change token functionality myself using cloud functions. The issue, however, is that two devices can try to perform an update simultaneously and I would need to find a way to ensure that one of these updates is executed in full before the other one starts (so that one of them fails with "invalid change token").
It sounds to me like a common design pattern, but I am struggling to find any ideas as to how to implement it correctly in Firebase.
Hence, I would like to ask you for suggestions on how I should proceed with migrating the "change token" functionality from CloudKit to Firestore.
Note, I am making my first steps in backend development, so my terminology is far from perfect.
firebase synchronization google-cloud-firestore google-cloud-functions cloudkit
asked Jan 1 at 18:36
Andriy GordiychukAndriy Gordiychuk
4,23511444
I want to migrate my iOS app from CloudKit to Firestore. Most of the architectural changes are simple, but there is one caveat that I do not understand how to overcome.
In CloudKit, I can save a change token on the client and pass it to CloudKit functions when fetching or saving data. During fetch, it ensures that I receive only those updates, which I did not previously receive. During save, unless my change token corresponds to the latest available one, the operation fails until I perform a fetch first. In my case, this design is ideal.
Unfortunately, it seems like such functionality is not available out of the box in Firestore. For example, when attaching a listener to document snapshot, there is no way to tell Firestore "Here is a token X corresponding to the last update which I have and I want to receive all updates following it".
I could theoretically implement the change token functionality myself using cloud functions. The issue, however, is that two devices can try to perform an update simultaneously and I would need to find a way to ensure that one of these updates is executed in full before the other one starts (so that one of them fails with "invalid change token").
It sounds to me like a common design pattern, but I am struggling to find any ideas as to how to implement it correctly in Firebase.
Hence, I would like to ask you for suggestions on how I should proceed with migrating the "change token" functionality from CloudKit to Firestore.
Note, I am making my first steps in backend development, so my terminology is far from perfect.
firebase synchronization google-cloud-firestore google-cloud-functions cloudkit
firebase synchronization google-cloud-firestore google-cloud-functions cloudkit
asked Jan 1 at 18:36
Andriy GordiychukAndriy Gordiychuk
4,23511444
asked Jan 1 at 18:36
Andriy GordiychukAndriy Gordiychuk
4,23511444
asked Jan 1 at 18:36
Andriy GordiychukAndriy Gordiychuk
4,23511444
asked Jan 1 at 18:36
Andriy GordiychukAndriy Gordiychuk
4,23511444
asked Jan 1 at 18:36
Andriy GordiychukAndriy Gordiychuk
4,23511444
4,23511444
add a comment |
add a comment |
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