6.11.3 GetNotification

GetNotification method registers a callback function to receive notifications of system data. It takes a set of input parameters that specifies entity and key of System Attribute.
It is available in only asynchronous mode.

Input parameter specifies the Entity and Key of system attribute, and system data.

Name	Type	Range	Description
Entity	unicode string	For complete list of supported Entities, refer Key Values 6.11.4 section.	Entity of system attribute. For example, `Battery` `Network` and so on.
Key	unicode string	For complete list of supported Keys, refer Key Values 6.11.4 section.	Key of system attribute. For example, `BatteryStrenth` `CurrentNetwork` and so on.
[SystemData]	map	Status information Status: int `DriveInfo` Drive: unicode string CriticalSpace: int	This is an optional parameter from API definition point of view. For some system attributes, you need to specify input. This map must contain one of the input data specifiers defined in System Data. For more information on input specifier refer the section Key Values 6.11.4. Here are some system attributes for which status information is used as input specifier. `DriveNumber` and critical space to be specified for drive critical memory notifications. For example, Battery- `BatteryStrength` (Threshold Strength value). Network- `Signal` (Threshold Signal value).

Output parameter returns an object that contains the requested information. It also contains ErrorCode and an ErrorMessage, if the operation fails.

Name	Type	Range	Description
`ErrorCode`	int	NA	Contains the SAPI specific error code when the operation fails.
`ErrorMessage`	string	NA	Error Description in Engineering English.
`ReturnValue`	map(System Data) Entity: string Key: string	For complete range of keys for the particular map, refer to System Data in Key Value section.	Output map always contains Entity and Key. Rest of the elements in the map depends on requested system attribute (Entity-Key). It will be one of the data specifiers defined in System Data. On requesting drive information using system attribute (for example: `Memory`, `DriveInfo`), `ReturnValue` map will contain Keys defined in `DriveInfo` Map.

Error code value	Description
`1002`	Bad argument type
`1003`	Missing argument
`1006`	Service not ready
`1010`	Entry exists
`1012`	Item not found

Error messages	Description
`SysInfo:GetNotification: Insufficient Arguments to process`	At least two input arguments are expected to process `GetNotification` service request.
`SysInfo:GetNotification: Entity:Input Parameter Missing`	Indicates mandatory parameter Entity is missing in the service request.
`SysInfo:GetNotification: Key:Input Parameter Missing`	Indicates mandatory parameter Key is missing in the service request.
`SysInfo:GetNotification: Incorrect SystemData Type, SystemData Must be a Map`	Indicates that either the optional parameter `SystemData` specified is not a map or content of the map is inappropriate to process request.
`SysInfo:GetNotification: Sync Version Not Supported`	This message is given when `GetNotification` is requested without specifying callback or `CmdOptions` set to Synchronous request type.

import scriptext
import e32

lock = e32.Ao_lock()
messaging_handle = scriptext.load('Service.SysInfo', 'ISysInfo')

def sysinfo_callback(trans_id, event_id, input_params):
    if event_id != scriptext.EventCompleted:   
# Check the event status
        print "Error in retrieving required info"
        print "Error code is: " + str(input_params["ReturnValue"]["ErrorCode"])
        if "ErrorMessage" in input_params["ReturnValue"]:
            print "Error message is: " + input_params["ReturnValue"]["ErrorMessage"]
    else:
        print "Current Battery charging value: " + str(input_params["ReturnValue"]["Status"])
    lock.signal()

# Make a request to get notification
event_id = sysinfo_handle.call("GetNotification", {"Entity": u"Battery", "Key": u"ChargingStatus"}, callback=sysinfo_callback)
lock.wait()

Interface	`ISysinfo`
Description	Registers a callback function for listening to notifications.
Response Model	Asynchronous
Pre-condition	ISysInfo Interface is loaded.
Post-condition	Returns the generic parameter system data on success.