10 ms·

Datastore API (beta)

207 points by gluegadget 13y ago

alexobenauer 13y ago
For the iOS library specifically, I wonder if it would be possible to build a library that would (nearly) automatically map a core data store in to this Datastore API. If so, including such functionality would make the library a no-brainer for many.
- ZitchDog 13y ago
  I think with NSIncrementalStore it would be totally doable, and a great alternative to Core Data Sync.
frankcaron 13y ago
I wonder how Apple will react to @dropbox's new Datastore sync in the long run. Hopefully it won't pull the rug out a la IAP, UDID, OF, ...
- jemeshsu 13y ago
  I would rather they react positively by opening up their iCloud API for web application for third parties. Apple already has such in place as can be seen from their cloud apps at icloud.com.
  - duaneb 13y ago
    Apple is a hardware company.
- callumjones 13y ago
  I highly doubt they would do anything to stifle Dropbox's syncing functionality in iOS. Apple is still focused on selling iOS devices and ensuring people keep buying iOS devices, they will do anything in their power to keep you happy. Limiting Dropbox functionality on iOS would be met my swift user opposition, something that doesn't guarantee recurring sales.
obilgic 13y ago
What app.net wanted to accomplish.
- WalterGR 13y ago
  At first glance it also looks like WinFS for the Cloud.
jimsilverman 13y ago
this is basically what iCloud was supposed to be.
BadassFractal 13y ago
What is the long term vision here? Is the idea that consumers will have little apps here and there that will procedurally interact with the owner's data on Dropbox? Or, is Dropbox making a product along the lines of S3 so that backends can consider using it too? I guess given how expensive space is at this point, that's not really an option.
- chacham15 13y ago
  dhouston has said more than once that he wants dropbox to be the filesystem of the internet.
mmahemoff 13y ago
Something I don't get about Dropbox API: Why can't I just throw URLs at it? If a user wants to save <thing at URL>, I have to pull it to my server and push it into Dropbox. Dropbox could just have grabbed it directly and in many cases, won't even have to thanks, to system-wide caching. (This is based on the last time I looked at the API; maybe this is supported now, but I don't think so.)
- timdorr 13y ago
  You're describing the Saver Drop-In: https://www.dropbox.com/developers/dropins/saver https://www.dropbox.com/developers/dropins/saver
  - natch 13y ago
    Can the Saver Drop-In be used with arbitrary third-party URLs? To me this is what was being described, so if not, then no, it's not describing the Saver Drop-In.
    - rpearl 13y ago
      Yes, you can provide arbitrary URLs to the Saver and our (Dropbox's) servers will download them, assuming they are publicly available. (Note: I am an engineer at Dropbox and worked on this product.)
      - natch 13y ago
        Thanks. Off topic but slightly related if I'm going to rely on your service as a developer: as an engineer at Dropbox, can you tell me why I am seeing random photos that are not mine in my dropbox Photos folder? And does this mean that other people get to see my random photos? Edit: only on iOS. And maybe it's not a "folder" per se, it's the second tab from the left at the bottom of the screen.
        gkurtz1 13y ago
        That photos tab shows you photos from anywhere in your Dropbox account, so these photos may be from shared folders you're a member of. (Likewise, other people can only see your photos if you shared them with them.) Another thing that may happen is someone "camera uploaded" their photos to your account (e.g., by plugging into your computer and choosing to import photos when Dropbox asked.) If you're still not sure where they're coming from, you should open a ticket: https://www.dropbox.com/support/s/92/3201098/c/2 https://www.dropbox.com/support/s/92/3201098/c/2
joejohnson 13y ago
So Dropbox is becoming a more-direct competitor with iCloud. Meh. I'd rather they work on an end-to-end encryption system with a focus on ease of use.
- Afforess 13y ago
  Hacker News is a tiny audience. I don't see any business sense in focusing on features that 0.1% of users want.
  - albertyw 13y ago
    Not to sound self-righteous, but the HN audience (or more plausibly, some subset within) has a high influence on what the rest of the world sees and wants. Any Dropbox employees read HN?
- afarrell 13y ago
  If they did want to serve this audience, they would actually want to make it easy for someone (possibly the employees themselves) to build a Free encryption layer on top of them.
- iamclovin 13y ago
  I think this is exactly the direction they should take.
oellegaard 13y ago
Such an awesome idea. However, in light of the recent events the first thing to come up in my mind when I see "datastore" and a US corporation is "PRISM integration". I'd like to see proper encryption of Dropbox as the next feature, so that we - innocent users- are not uploading our data to the US government.
- redblacktree 13y ago
  I combine dropbox with TrueCrypt for sensitive stuff. For me, that's just digital copies of important documents.
  - aasarava 13y ago
    So are you just syncing entire truecrypt .tc files to Dropbox? Does that work incrementally or does the entire .tc file have to get resent every time you modify a file within?
    - redblacktree 13y ago
      The entire file may be resent, but practically it works just fine for me. The total volume is only 250mb and it is updated infrequently.
    - Afforess 13y ago
      The entire file is resent.
      - BHSPitMonkey 13y ago
        Citation? Other comments are offering conflicting reports.
      - sigil 13y ago
        No, only changed blocks are resent. The scattering effect of Truecrypt encryption plus the relatively large blocksize does amplify the number of changed blocks somewhat. Previous investigation and results: http://news.ycombinator.com/item?id=2546626 http://news.ycombinator.com/item?id=2546626
jonaldomo 13y ago
After quickly clicking through the api documentation I don't understand why I would use this over a hosted NoSql database like mongohq. I still like having additional options though.
- forgotAgain 13y ago
  Off-line access.
- icefox 13y ago
  Perhaps you don't want to host a db just for user data.
peterkelly 13y ago
The biggest problem right now with online file storage services (sorry, I meant "The Cloud") is that while they all do basically the same stuff, there's no standard protocol for accessing them. It's a bit like if every website used a custom protocol instead of HTTP, and web browser vendors had to explicitly collaborate with each web site (or use the website's SDK) in order to be able to retrieve content. Imagine this: All the major players in the space (Dropbox, Box, Google Drive, Skydrive, Sugarsync etc.) as well as app developers got together and came up with a standard way of doing this that makes it possible to use a single protocol & API for all online storage providers. I see this being a good thing for everyone - users can choose whatever service they want, app developers can easily provide their customers with a ton of options, and storage providers don't have to explicitly produce their own SDK or court developers to do integration with their service. We did have WebDAV, but that doesn't seem to be widely adopted by any of the major players. I've been facing this problem myself with my own app; it's a lot of work to support all the major services and this is really just plumbing stuff that everyone would rather be taken care of so they can focus on the more important stuff. I had a meeting with Box recently where I proposed the idea of an open source framework for iOS which would provide a common native API that abstracts over all the different REST APIs used by different storage providers. The people I spoke to seemed quite open to the idea and agreed that it would be useful. I don't think a library like this would necessary be considered a bad thing by any of the major players, as it evens out the playing field and makes it easy to support different services. If you're interested in taking part and/or using such an API in your iOS app, I'd love to hear your thoughts on the matter. I have some code already (which I haven't released yet) and am looking to clean up the API a bit, but I think it would be useful to a lot of developers.
- icebraining 13y ago
  Big players aren't interested in anything that reduces lock-in. Seamless integration is one of the keypoints they have to get you to use their services. Obligatory presentation by Bruce Schneier on the online feudalism: http://www.infoq.com/presentations/cloud-security http://www.infoq.com/presentations/cloud-security
  - 13y ago
deleted 13y ago
[deleted]
sunkid 13y ago
As usual, men invent thing, women feel excluded, women try to invade, women are told to feck off, men eventually give up, women ruin thing, women celebrate "accomplishment". Rinse and repeat ad nauseam. yawn This is referred to this thread by the way: https://news.ycombinator.com/item?id=6014716 https://news.ycombinator.com/item?id=6014716 (Where apparently I can't comment, lol.)
johnrob 13y ago
Grammar check: "These days, your app need to store and sync more than just files."
munificent 13y ago
I'd like to coin a modern update of Zawinski's Law[1]: Every software company attempts to expand until it offers a cloud-based platform API. Those companies which cannot do so are replaced by ones which do. [1]: http://en.wikipedia.org/wiki/Jamie_Zawinski#Zawinski.27s_law_of_software_envelopment http://en.wikipedia.org/wiki/Jamie_Zawinski#Zawinski.27s_law...
modarts 13y ago
Why would I use this over something like Parse?
- joeblau 13y ago
  I haven't looked into it but it may be cheaper. That being said, both Parse and Azure support more platforms than this offering. I think that even Firebase has an service in this space as well.
fireboi 13y ago
are there any kind souls that could help please explain the difference between dropbox datastore, firebase and parse? thank you.
- sankethkatta 13y ago
  In comparison to firebase, this solves the offline sync problem, if your user is offline, you can still save to dropbox datastore locally, when you get a connection, it will automatically sync and take care of conflict resolution.
  - mikelehen 13y ago
    Firebase dev here. :-) Firebase does handle offline syncing / conflict resolution. If you have a Firebase app open and you lose network connectivity, the app still continues to work fine and any modifications you make will be synced back to Firebase when you regain connectivity. What we don't (quite yet) do is handle the case where you make changes, kill the app (without regaining network connectivity), restart the app, and then get network connectivity, but that's coming soon. As for other differences, Dropbox Datastore seems to be tightly tied to Dropbox, so the end user for your app must have a Dropbox account (and if they want to collaborate with other users, those users must also have Dropbox accounts, etc.). So it's really for building apps on top of Dropbox. Firebase and Parse are just generic backends, with no ties to other services, so your end users don't need anything to use your app. As for differentiating Parse and Firebase, Firebase deals with data in real-time, pushing updates to apps as soon as data changes. Parse is a traditional request/response model, where your app has to explicitly "refresh" to get new data.
    - fireboi 13y ago
      good stuff.. thanks mike!
    - sankethkatta 13y ago
      Thanks mike, I didn't realize firebase did offline syncing now!
deleted 13y ago
[deleted]
jimbokun 13y ago
"List – A special value that can contain other values, though not other lists." https://www.dropbox.com/developers/datastore/tutorial/ios#records https://www.dropbox.com/developers/datastore/tutorial/ios#re... Seems like a very significant limitation. No mechanism for storing hierarchical data structures. For example, this is certainly not capable of storing arbitrary JSON data as a Record.
- est 13y ago
  There's also limit on Postgres hstore and arrays. No nested sturcture.
joeblau 13y ago
Does anyone know of an OSS alternative to this similar to http://helios.io/ http://helios.io/ that supports Android/iOS?
- jchrisa 13y ago
  Couchbase Lite is an embedded JSON database with sync capability. It's Apache licensed and available for iOS and Android: https://github.com/couchbase/couchbase-lite-ios https://github.com/couchbase/couchbase-lite-ios https://github.com/couchbase/couchbase-lite-android https://github.com/couchbase/couchbase-lite-android
  - joeblau 13y ago
    Thanks for the link to this library. It seems like I would still need to implement a lot of features like login, but it's a great start.
    - jchrisa 13y ago
      We ship with support for login with Mozilla Persona. Hope to have baked-in support for Facebook Connect soon. Of course you can use it with any auth you want, but you'll end up writing some code...
makeramen 13y ago
As someone who has been playing around with Parse and Firebase SDKs (on Android), this seems to be the first one that offers full 2-way sync. I haven't actually used it yet but it seems that way due to the presence of conflict resolution [1]. I'm personally really excited about that for mobile side-projects and MVPs. Parse has an offline cache, that only caches query results and not actual objects. So any local saves/updates are not reflected until you get network access again, unless you manually implement your own cache. Firebase is better at handling realtime changes, but is lacking in any realtime capabilities at the moment. Also Firebase's mobile authentication SDK still isn't released yet so no way to handle users yet either. [1]: https://www.dropbox.com/developers/datastore/tutorial/android#conflicts https://www.dropbox.com/developers/datastore/tutorial/androi...
- pavpanchekha 13y ago
  Yeah, the Datastores API does two-way synchronization. Also, offline caches are done for you and offline changes are propagated (with conflict resolution) when the internet comes back up.
- makeramen 13y ago
  Correction: "lacking in any realtime capabilities" should read "offline capabilities". And by that I mean offline without manually managing cache. Also by 2-way sync I mean 2-way cache sync. Firebase is actually really good with 2-way sync, but without cache/offline (yet) it's kind of a dealbreaker for me.
sigil 13y ago
So now app developers have a choice: they can use iCloud or Dropbox to manage distributed app state. Any iOS app developers (I'm not one) care to compare & contrast the two options? It looks like Dropbox may be using Operational Transformation [0] to merge changes to lists: Lists are special field values. They contain an ordered list of other values, though not other lists. Lists can be manipulated via four list operations: put (i.e. replace), move, insert, and delete. These list operations allow Dropbox to handle merging changes to the structure of the list automatically. [1] iCloud, on the other hand, uses the coarser, state-centric approach of whole document versioning. [2] (Edit: okay, key-value property versioning is also available.) But iCloud lets the app control conflict resolution, while the Dropbox Datastore API only lets you choose from a predefined set of conflict resolution strategies. [3] Which approach provides greater value to the app developer? Has Dropbox realized here that developers are just not comfortable implementing a custom merge strategy for entire documents, and not having to worry about this is worth some loss of control? [0] http://en.wikipedia.org/wiki/Operational_transformation http://en.wikipedia.org/wiki/Operational_transformation [1] https://www.dropbox.com/developers/datastore/tutorial/ios#records https://www.dropbox.com/developers/datastore/tutorial/ios#re... [2] http://developer.apple.com/library/ios/#documentation/DataManagement/Conceptual/DocumentBasedAppPGiOS/ResolveVersionConflicts/ResolveVersionConflicts.html http://developer.apple.com/library/ios/#documentation/DataMa... [3] https://www.dropbox.com/developers/datastore/tutorial/ios#conflicts https://www.dropbox.com/developers/datastore/tutorial/ios#co...
- hboon 13y ago
  Not answering your question, but developers can also use http://parse.com http://parse.com or similar.

207 points by gluegadget 13y ago

For the iOS library specifically, I wonder if it would be possible to build a library that would (nearly) automatically map a core data store in to this Datastore API. If so, including such functionality would make the library a no-brainer for many.

ZitchDog 13y ago
I think with NSIncrementalStore it would be totally doable, and a great alternative to Core Data Sync.

frankcaron 13y ago

I wonder how Apple will react to @dropbox's new Datastore sync in the long run. Hopefully it won't pull the rug out a la IAP, UDID, OF, ...

jemeshsu 13y ago
I would rather they react positively by opening up their iCloud API for web application for third parties. Apple already has such in place as can be seen from their cloud apps at icloud.com.
- duaneb 13y ago
  Apple is a hardware company.
callumjones 13y ago
I highly doubt they would do anything to stifle Dropbox's syncing functionality in iOS. Apple is still focused on selling iOS devices and ensuring people keep buying iOS devices, they will do anything in their power to keep you happy. Limiting Dropbox functionality on iOS would be met my swift user opposition, something that doesn't guarantee recurring sales.

obilgic 13y ago

What app.net wanted to accomplish.

WalterGR 13y ago
At first glance it also looks like WinFS for the Cloud.

jimsilverman 13y ago

this is basically what iCloud was supposed to be.

BadassFractal 13y ago

What is the long term vision here? Is the idea that consumers will have little apps here and there that will procedurally interact with the owner's data on Dropbox? Or, is Dropbox making a product along the lines of S3 so that backends can consider using it too? I guess given how expensive space is at this point, that's not really an option.

chacham15 13y ago
dhouston has said more than once that he wants dropbox to be the filesystem of the internet.

mmahemoff 13y ago

Something I don't get about Dropbox API: Why can't I just throw URLs at it? If a user wants to save <thing at URL>, I have to pull it to my server and push it into Dropbox. Dropbox could just have grabbed it directly and in many cases, won't even have to thanks, to system-wide caching. (This is based on the last time I looked at the API; maybe this is supported now, but I don't think so.)

timdorr 13y ago
You're describing the Saver Drop-In: https://www.dropbox.com/developers/dropins/saver https://www.dropbox.com/developers/dropins/saver
- natch 13y ago
  Can the Saver Drop-In be used with arbitrary third-party URLs? To me this is what was being described, so if not, then no, it's not describing the Saver Drop-In.
  - rpearl 13y ago
    Yes, you can provide arbitrary URLs to the Saver and our (Dropbox's) servers will download them, assuming they are publicly available. (Note: I am an engineer at Dropbox and worked on this product.)
    - natch 13y ago
      Thanks. Off topic but slightly related if I'm going to rely on your service as a developer: as an engineer at Dropbox, can you tell me why I am seeing random photos that are not mine in my dropbox Photos folder? And does this mean that other people get to see my random photos? Edit: only on iOS. And maybe it's not a "folder" per se, it's the second tab from the left at the bottom of the screen.
      - gkurtz1 13y ago
        That photos tab shows you photos from anywhere in your Dropbox account, so these photos may be from shared folders you're a member of. (Likewise, other people can only see your photos if you shared them with them.) Another thing that may happen is someone "camera uploaded" their photos to your account (e.g., by plugging into your computer and choosing to import photos when Dropbox asked.) If you're still not sure where they're coming from, you should open a ticket: https://www.dropbox.com/support/s/92/3201098/c/2 https://www.dropbox.com/support/s/92/3201098/c/2

joejohnson 13y ago

So Dropbox is becoming a more-direct competitor with iCloud. Meh. I'd rather they work on an end-to-end encryption system with a focus on ease of use.

Afforess 13y ago
Hacker News is a tiny audience. I don't see any business sense in focusing on features that 0.1% of users want.
- albertyw 13y ago
  Not to sound self-righteous, but the HN audience (or more plausibly, some subset within) has a high influence on what the rest of the world sees and wants. Any Dropbox employees read HN?
afarrell 13y ago
If they did want to serve this audience, they would actually want to make it easy for someone (possibly the employees themselves) to build a Free encryption layer on top of them.
iamclovin 13y ago
I think this is exactly the direction they should take.

oellegaard 13y ago

Such an awesome idea. However, in light of the recent events the first thing to come up in my mind when I see "datastore" and a US corporation is "PRISM integration". I'd like to see proper encryption of Dropbox as the next feature, so that we - innocent users- are not uploading our data to the US government.

redblacktree 13y ago
I combine dropbox with TrueCrypt for sensitive stuff. For me, that's just digital copies of important documents.
- aasarava 13y ago
  So are you just syncing entire truecrypt .tc files to Dropbox? Does that work incrementally or does the entire .tc file have to get resent every time you modify a file within?
  - redblacktree 13y ago
    The entire file may be resent, but practically it works just fine for me. The total volume is only 250mb and it is updated infrequently.
  - Afforess 13y ago
    The entire file is resent.
    - BHSPitMonkey 13y ago
      Citation? Other comments are offering conflicting reports.
    - sigil 13y ago
      No, only changed blocks are resent. The scattering effect of Truecrypt encryption plus the relatively large blocksize does amplify the number of changed blocks somewhat. Previous investigation and results: http://news.ycombinator.com/item?id=2546626 http://news.ycombinator.com/item?id=2546626

jonaldomo 13y ago

After quickly clicking through the api documentation I don't understand why I would use this over a hosted NoSql database like mongohq. I still like having additional options though.

forgotAgain 13y ago
Off-line access.
icefox 13y ago
Perhaps you don't want to host a db just for user data.

peterkelly 13y ago

The biggest problem right now with online file storage services (sorry, I meant "The Cloud") is that while they all do basically the same stuff, there's no standard protocol for accessing them. It's a bit like if every website used a custom protocol instead of HTTP, and web browser vendors had to explicitly collaborate with each web site (or use the website's SDK) in order to be able to retrieve content. Imagine this: All the major players in the space (Dropbox, Box, Google Drive, Skydrive, Sugarsync etc.) as well as app developers got together and came up with a standard way of doing this that makes it possible to use a single protocol & API for all online storage providers. I see this being a good thing for everyone - users can choose whatever service they want, app developers can easily provide their customers with a ton of options, and storage providers don't have to explicitly produce their own SDK or court developers to do integration with their service. We did have WebDAV, but that doesn't seem to be widely adopted by any of the major players. I've been facing this problem myself with my own app; it's a lot of work to support all the major services and this is really just plumbing stuff that everyone would rather be taken care of so they can focus on the more important stuff. I had a meeting with Box recently where I proposed the idea of an open source framework for iOS which would provide a common native API that abstracts over all the different REST APIs used by different storage providers. The people I spoke to seemed quite open to the idea and agreed that it would be useful. I don't think a library like this would necessary be considered a bad thing by any of the major players, as it evens out the playing field and makes it easy to support different services. If you're interested in taking part and/or using such an API in your iOS app, I'd love to hear your thoughts on the matter. I have some code already (which I haven't released yet) and am looking to clean up the API a bit, but I think it would be useful to a lot of developers.

icebraining 13y ago
Big players aren't interested in anything that reduces lock-in. Seamless integration is one of the keypoints they have to get you to use their services. Obligatory presentation by Bruce Schneier on the online feudalism: http://www.infoq.com/presentations/cloud-security http://www.infoq.com/presentations/cloud-security
- 13y ago

deleted 13y ago

[deleted]

sunkid 13y ago

As usual, men invent thing, women feel excluded, women try to invade, women are told to feck off, men eventually give up, women ruin thing, women celebrate "accomplishment". Rinse and repeat ad nauseam. yawn This is referred to this thread by the way: https://news.ycombinator.com/item?id=6014716 https://news.ycombinator.com/item?id=6014716 (Where apparently I can't comment, lol.)

johnrob 13y ago

Grammar check: "These days, your app need to store and sync more than just files."

munificent 13y ago

I'd like to coin a modern update of Zawinski's Law[1]: Every software company attempts to expand until it offers a cloud-based platform API. Those companies which cannot do so are replaced by ones which do. [1]: http://en.wikipedia.org/wiki/Jamie_Zawinski#Zawinski.27s_law_of_software_envelopment http://en.wikipedia.org/wiki/Jamie_Zawinski#Zawinski.27s_law...

modarts 13y ago

Why would I use this over something like Parse?

joeblau 13y ago
I haven't looked into it but it may be cheaper. That being said, both Parse and Azure support more platforms than this offering. I think that even Firebase has an service in this space as well.

fireboi 13y ago

are there any kind souls that could help please explain the difference between dropbox datastore, firebase and parse? thank you.

sankethkatta 13y ago
In comparison to firebase, this solves the offline sync problem, if your user is offline, you can still save to dropbox datastore locally, when you get a connection, it will automatically sync and take care of conflict resolution.
- mikelehen 13y ago
  Firebase dev here. :-) Firebase does handle offline syncing / conflict resolution. If you have a Firebase app open and you lose network connectivity, the app still continues to work fine and any modifications you make will be synced back to Firebase when you regain connectivity. What we don't (quite yet) do is handle the case where you make changes, kill the app (without regaining network connectivity), restart the app, and then get network connectivity, but that's coming soon. As for other differences, Dropbox Datastore seems to be tightly tied to Dropbox, so the end user for your app must have a Dropbox account (and if they want to collaborate with other users, those users must also have Dropbox accounts, etc.). So it's really for building apps on top of Dropbox. Firebase and Parse are just generic backends, with no ties to other services, so your end users don't need anything to use your app. As for differentiating Parse and Firebase, Firebase deals with data in real-time, pushing updates to apps as soon as data changes. Parse is a traditional request/response model, where your app has to explicitly "refresh" to get new data.
  - fireboi 13y ago
    good stuff.. thanks mike!
  - sankethkatta 13y ago
    Thanks mike, I didn't realize firebase did offline syncing now!

deleted 13y ago

[deleted]

jimbokun 13y ago

"List – A special value that can contain other values, though not other lists." https://www.dropbox.com/developers/datastore/tutorial/ios#records https://www.dropbox.com/developers/datastore/tutorial/ios#re... Seems like a very significant limitation. No mechanism for storing hierarchical data structures. For example, this is certainly not capable of storing arbitrary JSON data as a Record.

est 13y ago
There's also limit on Postgres hstore and arrays. No nested sturcture.

joeblau 13y ago

Does anyone know of an OSS alternative to this similar to http://helios.io/ http://helios.io/ that supports Android/iOS?

jchrisa 13y ago
Couchbase Lite is an embedded JSON database with sync capability. It's Apache licensed and available for iOS and Android: https://github.com/couchbase/couchbase-lite-ios https://github.com/couchbase/couchbase-lite-ios https://github.com/couchbase/couchbase-lite-android https://github.com/couchbase/couchbase-lite-android
- joeblau 13y ago
  Thanks for the link to this library. It seems like I would still need to implement a lot of features like login, but it's a great start.
  - jchrisa 13y ago
    We ship with support for login with Mozilla Persona. Hope to have baked-in support for Facebook Connect soon. Of course you can use it with any auth you want, but you'll end up writing some code...

makeramen 13y ago

As someone who has been playing around with Parse and Firebase SDKs (on Android), this seems to be the first one that offers full 2-way sync. I haven't actually used it yet but it seems that way due to the presence of conflict resolution [1]. I'm personally really excited about that for mobile side-projects and MVPs. Parse has an offline cache, that only caches query results and not actual objects. So any local saves/updates are not reflected until you get network access again, unless you manually implement your own cache. Firebase is better at handling realtime changes, but is lacking in any realtime capabilities at the moment. Also Firebase's mobile authentication SDK still isn't released yet so no way to handle users yet either. [1]: https://www.dropbox.com/developers/datastore/tutorial/android#conflicts https://www.dropbox.com/developers/datastore/tutorial/androi...

pavpanchekha 13y ago
Yeah, the Datastores API does two-way synchronization. Also, offline caches are done for you and offline changes are propagated (with conflict resolution) when the internet comes back up.
makeramen 13y ago
Correction: "lacking in any realtime capabilities" should read "offline capabilities". And by that I mean offline without manually managing cache. Also by 2-way sync I mean 2-way cache sync. Firebase is actually really good with 2-way sync, but without cache/offline (yet) it's kind of a dealbreaker for me.

sigil 13y ago

So now app developers have a choice: they can use iCloud or Dropbox to manage distributed app state. Any iOS app developers (I'm not one) care to compare & contrast the two options? It looks like Dropbox may be using Operational Transformation [0] to merge changes to lists: Lists are special field values. They contain an ordered list of other values, though not other lists. Lists can be manipulated via four list operations: put (i.e. replace), move, insert, and delete. These list operations allow Dropbox to handle merging changes to the structure of the list automatically. [1] iCloud, on the other hand, uses the coarser, state-centric approach of whole document versioning. [2] (Edit: okay, key-value property versioning is also available.) But iCloud lets the app control conflict resolution, while the Dropbox Datastore API only lets you choose from a predefined set of conflict resolution strategies. [3] Which approach provides greater value to the app developer? Has Dropbox realized here that developers are just not comfortable implementing a custom merge strategy for entire documents, and not having to worry about this is worth some loss of control? [0] http://en.wikipedia.org/wiki/Operational_transformation http://en.wikipedia.org/wiki/Operational_transformation [1] https://www.dropbox.com/developers/datastore/tutorial/ios#records https://www.dropbox.com/developers/datastore/tutorial/ios#re... [2] http://developer.apple.com/library/ios/#documentation/DataManagement/Conceptual/DocumentBasedAppPGiOS/ResolveVersionConflicts/ResolveVersionConflicts.html http://developer.apple.com/library/ios/#documentation/DataMa... [3] https://www.dropbox.com/developers/datastore/tutorial/ios#conflicts https://www.dropbox.com/developers/datastore/tutorial/ios#co...

hboon 13y ago
Not answering your question, but developers can also use http://parse.com http://parse.com or similar.