> For the complete documentation index, see [llms.txt](https://developer.magtek.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.magtek.com/sdks-and-tools/universal-sdk-documentation/ios/mtusdkdelegate-delegate.md). # MTUSDKDelegate Delegate MTUniversal API will invoke the callback function in this chapter to provide the requested data and/or a detailed response. To delegate the event, implements the MTUSDKDelegate interface. ### onDeviceList Handles BLE Service and EA Service events. Use this to find a BLE device or EA accessory. {% code overflow="wrap" %} ``` (void) onDeviceList: (id) instance withConnectionType: (MTU_ConnectionType) connectionType deviceList: (NSArray *) deviceList; ``` {% endcode %}
ParameterDescription
instanceInstance identifier.
withConnectionTypeEnumerated connection type.
deviceListArray of devices.
Return Value: None ### didSystemUpdateState Handles update of host system state. {% code overflow="wrap" %} ``` (void) onDeviceList: (SystemState) state; ``` {% endcode %}
ParameterDescription
stateEnumerated system state.
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