Hi, thanks @maxk.
Here are some responses to those questions. If the original person is around and needs further development of the answer or needs more details please reach out!
Q: Do validation rules containing data elements from different data sets also work on the mobile?
A: (pending)
Q: Is there available function to hash/produce unique identifications (number or string) from TEI in tracker program now?
A: Yes, there is no difference between the web version and the Android version while using the patter generation and marking the attributes as uniques (either accross the Organisation Unit or the whole system). Please see: Home - DHIS2 Documentation however, note that the Android will prefetch a specific number of values and this might require some prethinking in terms of (offline time and usage -if you are going to be offline for long time you might need to download many more) and when using dates the values might expire.
Q: Does the android or web input allow you to upload some images and video or mp3/wav audio format at one time into DHIS?
A: At the moment the mobile App only allows uploading images. So far we have never heard of any implementation that could require uploading video or audio files. If this is important for your implementation please contact us so we can evaluate.
Q: What’s the max number of TEIs and events the android application is able to pull to the mobile device? Any advice on instances that have large numbers of TEIs and events?
A: This has not a straight answer. Unfortunately each implementation should carefully analyse their case and decide which numbers to use. As an example some events might contain lot of information but could work on a really good Internet connection therefore it shouldn’t be a problem. However in places where connectivity is an issue the amount should probably be decreased.
By default the Application will pull 1000 events and 500 TEI (this can be modified manually in the Settings > Sync parameters). In order to facilitate the work of the implementers this can be now centrally managed with the Android settings web app ( NEW! DHIS2 Android Settings Web App version 1.0 is released).
Please also note that we strongly recommend limiting the scope of the Android user to what they will need on the field. A common mistake is assigning the Android user the whole Organisation Unit tree and therefore the amount of data and metadata downloaded might be too much.