Why is my iOS app not suggested in the "Open in..." dialog? - ios

Question

I am currently working on a "share" feature in my app. I have custom objects that I am parsing to JSON and I currently have a working implementation to export them as a "___.blueprint" file. So I have created my own custom extension and I have set up everything when it comes to the UTIs and all.
Exporting works well and I have no issue when sending it via email. I can easy tap the mail attachment and select my own app. Importing and handling the data inside the app works as well.
However, When I send the file via AirDrop or messages, iOS doesn't know what to do with it. It doesn't suggest my app as an option to open it with. My info.plist looks like this:
<array>
<dict>
<key>CFBundleTypeName</key>
<string>Blueprint Data</string>
<key>CFBundleTypeRole</key>
<string>Editor</string>
<key>LSHandlerRank</key>
<string>Owner</string>
<key>LSItemContentTypes</key>
<array>
<string>com.ferdinandgoeldner.breadme.blueprint</string>
</array>
</dict>
</array>
...
<key>UTExportedTypeDeclarations</key>
<array>
<dict>
<key>UTTypeConformsTo</key>
<array>
<string>public.data</string>
</array>
<key>UTTypeDescription</key>
<string>Blueprint Data</string>
<key>UTTypeIconFiles</key>
<array/>
<key>UTTypeIdentifier</key>
<string>com.ferdinandgoeldner.breadme.blueprint</string>
<key>UTTypeTagSpecification</key>
<dict>
<key>public.filename-extension</key>
<array>
<string>blueprint</string>
</array>
<key>public.mime-type</key>
<array>
<string>blueprint</string>
</array>
</dict>
</dict>
</array>
<key>UTImportedTypeDeclarations</key>
<array>
<dict>
<key>UTTypeConformsTo</key>
<array>
<string>public.data</string>
</array>
<key>UTTypeDescription</key>
<string>Blueprint Data</string>
<key>UTTypeIconFiles</key>
<array/>
<key>UTTypeIdentifier</key>
<string>com.ferdinandgoeldner.breadme.blueprint</string>
<key>UTTypeTagSpecification</key>
<dict>
<key>public.filename-extension</key>
<array>
<string>blueprint</string>
</array>
<key>public.mime-type</key>
<array>
<string>blueprint</string>
</array>
</dict>
</dict>
</array>
I am really lost as to why iOS does allow me to direct the file to my app which can clearly handle the format, but does not think of letting me "open" the file in my application. What am I missing?

Answer 1

I got it to work!
I am not entirely sure what solved it, though.
Here are the steps I performed that made it work.
I chose a more specific UTI type.
Deinstalled all versions of my app.
I created a UTI with a shorter extension (.bmb)
I am pretty sure that .blueprint is a datatype that is not super unique, so I chose an extension that's more unique.
I also carefully ready this page of the Apple Developer Documentation. That also seemed to help me get a better grasp of how to make this stuff happen and what was going on under the hood.
I am still partially unsure of what solved the issue but tweaking several parameters made it happen.
To whoever finds this thread: Good luck. It is possible even though it seems like nothing helps. Keep experimenting and try the steps I described above. ;)