Working with files in Apple’s iOS is little strange. You don’t have a classic disk storage with all files like we know from other operating systems like desktop Windows, macOS, Linux or mobile Android and Windows 10 Mobile. Apps in iOS has its own storage where are documents stored – yea, your documents are in apps. Each supported app has its own sandbox where are your files stored. You have to open app (for example MS Word app) and then tap on document (in this case a .docx Word document). This may be pain if you use multiple apps to edit one file. For few years we have an option called “Open with…” so we can copy one file from app to another supported app. Since iOS 8, we got two great sharing features – Document Provider and Document Picker. How it works?
In few words – Document Picker can edit file stored in another app without copying it and Document Provider is app storage ability to provide access to files pickable by Document Picker (only Document Provider-enabled apps are shown while we are using that Document Picker). But that’s not all.
Function called “Open with…” available since iPhone 3GS allows to copy one file from one app to another app. It’s only copying files, nothing more. If you are working on one file with more apps, for example writing document in Word, then adding some content from Excel and then again continuing in Word, you have to always copy the newest version to another app, in this case from Word to Excel and then back to Word. Apps are not linked.
This was changed with Document Provider & Document Picker features. Just imagine: you have Word document (docx) in FTP client app. If this FTP client is Document Provider-enabled (like Transmit from Panic), you can open Word app and with Document Picker choose that document from FTP client. Then make changes in document and then close Word app. Now return to that FTP client and look at that docx file – yea, it was changed! No copying between apps needed. In short – file is EDITED by Word and STORED in FTP client. As I said, no copying needed.
How to enable this?
It’s easy. First, you need to download app(s) with enabled Document Provider feature (like iFiles 2, Transmit, PDF Expert, Documents by Readdle, Dropbox or iCloud Drive itself, etc.) and there store your files. First step done. Next, you will need app(s) with Document Picker feature (1Writer, Word, Excel, Textastic, PDF Expert, Pixelmator, etc.).
Now launch Document Picker-enabled app. With “add file menu” in your app (this warries by used app, try to find something like “add file”, “open file” or “+” sign). It will look something like this:
Sometimes (warries by used app) it may send you to iCloud Drive. It will look like this:
No worries, just tap on “Locations” in top-left corner:
By “More” switch you can manage which apps will show in menu.
And one extra screenshot – picking document from iFiles 2:
I hope it helped you to understand how it works.