iOS and DSM integration: document provider

Our last article looked into the addition of geofences to some of the DS apps, and how our engineers use them to get around some of the limitations when performing background tasks on iOS.

Today we will look into another major enhancement our apps are taking advantage of: application extensions. Announced at the last Apple World Developer Conference it introduces a major evolution for iOS, and opens incredible opportunities to simplify the way apps communicate and work together!

Sandboxing and iOS data silos

Traditionally, when using an iDevice, you’ve probably noticed the limited interaction between apps, especially accessing their respective files. It is generally possible by switching apps and using the (in)famous “Open with” function to copy the file into your editing app’s repository. Compare this with the application’s equivalent on PC or Mac, where the entire file system can be browsed freely to open any document. More importantly, modifications are made directly on the original file, whereas in iOS, each “Open with” duplicates it… which means waiting for the file to copy completely if it’s quite large, and using up double the amount of storage space on your iPhone. Take playing an .avi video in DS cloud for instance:


This is the design of iOS since the very first iPhone: a given app can only access its own dedicated folder, called “sandbox”. The main objective to this: compartmentalise the iDevice’s file system, and avoid your entire device being at risk should one app ever be compromised.


Apple has introduced a total of 7 app extensions in iOS 8, and the document provider is the one which boosts the interaction between apps while making it simpler. How exactly does it work?

Document providers in iOS 8

For Synology users, the document provider extension is supported in DS file and DS cloud, and serves as a portal for other apps to easily access not only the files contained in their sandboxes, but for any document on your DiskStation. Of the 4 available functions in the document provider, we support the 3 essential ones to work with major apps.

  1. Export: this operation allows to save a copy of the file at the desired destination. Lets take the Keynote app for instance: you’ve just given a presentation to your colleagues, and directly made a few changes on your the slides based on their feedback. Using “Send a copy”, and choosing DS file will save the presentation directly on your DiskStation. Export acts as a “save as” function, to avoid switching to DS file, and sending the copy directly to your cloud.

    Send a copy > Send to > DS file : 3 easy steps to save back to your DiskStation

    Send a copy > Send to > DS file : 3 easy steps to save back to your DiskStation

  2. Import provides the opposite and complementary functionality: a speedy way to import a file into an app and start editing them.
  3. Open may seem similar to Import, but differs in the way it imports the actual file by copying to the providing app’s sandbox, not that of the receiving app. What difference can that possibly make? Take the previous example of our slides. The changes will be made directly on the file in the providing app, and saved back on the original file when you actually close the file. No duplicate copy will be made in the editing app*: don’t waste the limited storage space of your iPhone, instead, leverage your DiskStation’s hard drives.


Supporting Open brings you a great deal more possibilities than the simple Import feature: you will find, however, that not all iOS applications out there have it implemented: therefore, having both operations supported will guarantee you are always able to pull documents from your Cloud to your iDevice.

You may be wondering why we would also include the document provider in DS cloud. After all, why spend time implementing this in a second app, when DS file provides access to the entire DiskStation’s file structure?

Using the document provider in DS cloud optimises the Open operation: when selecting a document, we mentioned it gets downloaded to DS file’s sandbox, a process of which the duration depends on the size of the file. Since DS cloud is designed to keep files synchronised between your device and the DiskStation, this completely removes any latency due to downloading.

Huge potential

The document provider in DS file and DS cloud can be seen as a portal to facilitate access to documents on your DiskStation by 3rd party apps. In other words, more flexibility and convenience to work on your documents with editing apps such as iWork (Keynote or Pages) or Office 365 (MS Word, Excel and PowerPoint apps), while still steering clear from iCloud and keeping your data safely on your DiskStation, as your personal cloud office.
But the document provider’s scope goes way beyond facilitating editing. Simplifying the transfer of files between 2 DiskStations, importing a document from iCloud to your Cloud Station, or even inserting an image directly into an article prepared in DS note: these are some smart additions made available last week with the latest updates to our iOS apps, and which we believe will make retrieving and transferring content between your different storage spaces easier than ever.

*if you test opening a .ppt in keynote, a duplicate will be made: this is a limitation of Apple which doesn’t support the .ppt format and converts it to .pages, creating a copy for that purpose. The document’s file type must be supported by the editing app: typically MS PowerPoint will be more suitable.