Storing user data
HMI service instances have got built-in key-value storage to keep persistent user data, such as settings, profile information etc.
The data is stored in HMI database (see the service instance configuration). Data values may contain any serializable object (strings, numbers, structures, arrays etc.)
Working with user data
Settings user data
A HMI application can set data field for the current logged in user using HTTP API method user_data.set.
Getting user data
A HMI application can get data for the current logged in user using HTTP API method user_data.get.
Deleting user data
A HMI application can delete data field for the current logged in user using HTTP API method user_data.delete.
The service configuration has got user_data field with the following sub-fields:
user_data: max_records: 100 max_record_length: 16384
max_records maximum number of data records a user can have
max_record_length maximum JSON-serialized length of a single record
To disable user data functionality, either set limits to zeroes or remove the field from the service configuration completely.