diff --git a/json_gateway.py b/json_gateway.py
new file mode 100644
index 0000000000000000000000000000000000000000..cac4420e5260fee0eb827a2cdd691c5977cc8537
--- /dev/null
+++ b/json_gateway.py
@@ -0,0 +1,166 @@
+import json
+import tango
+from tango.server import Device, attribute, command, run, device_property
+from tango import Attr, AttrWriteType, AttrQuality, DevState
+from tango.server import attribute
+
+# Type mapping for Tango data types
+TANGO_TYPE_MAPPING = {
+ "DEV_BOOLEAN": tango.DevBoolean,
+ "DEV_SHORT": tango.DevShort,
+ "DEV_LONG": tango.DevLong,
+ "DEV_FLOAT": tango.DevFloat,
+ "DEV_DOUBLE": tango.DevDouble,
+ "DEV_STRING": tango.DevString,
+}
+class JSONGateway(Device):
+ # JSON property to define dynamic attributes
+ dynamic_attributes_config = device_property(dtype=(str,), default_value=("[]"))
+ dynamic_attributes = {}
+ attributes_config = {}
+
+ def init_device(self):
+ print("init_device")
+ """Initialize the device and create dynamic attributes."""
+ super().init_device()
+ try:
+ # Parse the JSON configuration for dynamic attributes
+ self.attributes_config = json.loads(' '.join(self.dynamic_attributes_config))
+ except Exception as e:
+ print("ERROR: not valid JSON string in property dynamic_attributes_config.\nMust be:\n[\n {\"name\": \"name1\", \"type\": \"DEV_STRING\", \"writable\": true},\n {\"name\": \"name2\", \"type\": \"DEV_STRING\", \"writable\": false, \"value\": {\"device\":\"a/b/c\", \"operation\":\"command\", \"name\":\"Status\"}}\n]")
+ self.error_stream("Failed to initialize dynamic attributes: {e}")
+ try:
+ # Iterate through attribute definitions and create attributes
+ for attr_def in self.attributes_config:
+ print("attr_def: ", attr_def)
+ name = attr_def["name"]
+ dtype_str = attr_def["type"]
+ writable = attr_def.get("writable", False)
+ self.add_dynamic_attribute(name, dtype_str, writable)
+
+ except Exception as e:
+ print("Failed to initialize dynamic attributes:", e)
+ self.error_stream("Failed to initialize dynamic attributes: {e}")
+
+ # Define getter method
+ def read_callback(self, attr_obj):
+ name = attr_obj.get_name()
+ # print(name)
+ for attr_def in self.attributes_config:
+ if attr_def["name"]==name:
+ request = attr_def["value"]
+ target_device = request.get("device", None)
+ operation = request["operation"] # "command", "attribute", or "dynamic"
+ name = request["name"] # Command or attribute name
+ value = request.get("value") # Optional value for write operations
+ # Other operations: Command or Attribute
+ target_device = target_device or self.default_tango_device
+ device = tango.DeviceProxy(target_device)
+ if operation == "command":
+ result = device.command_inout(name, json.loads(value)) if value else device.command_inout(name)
+ elif operation == "attribute":
+ if value is not None:
+ # Write attribute
+ device.write_attribute(name, json.loads(value))
+ result = {"status": "success", "message": "Attribute {name} written successfully"}
+ else:
+ # Read attribute
+ result = device.read_attribute(name).value
+ else:
+ raise ValueError("Invalid operation type. Use 'command', 'attribute', or 'dynamic'.")
+ self.info_stream("Reading attribute '{name}': {value}")
+ # print(result)
+ attr_obj.set_value(json.dumps(result.tolist()))
+
+ # Define setter method (only if writable)
+ def write_callback(self, attr_obj):
+ # e.g. "{\"device\":\"g/gun/guntiming-p1.1\", \"operation\":\"command\", \"name\":\"Status\"}"
+ # "{\"device\":\"sr/sim/srElettra2_high_betax_long_straights\", \"operation\":\"command\", \"name\":\"GetHistExtendedOpticsData\", \"value\": \"[[0,100],[\\\"SR__DIAGNOSTICS__BPM_S04.09__horpos\\\"]]\"}"
+ value = attr_obj.get_write_value()
+ name = attr_obj.get_name()
+ for attr_def in self.attributes_config:
+ if attr_def["name"]==name:
+ try:
+ attr_def["value"] = json.loads(value)
+ except Exception as e:
+ raise ValueError("Invalid JSON string, please use syntax: {\"device\":\"a/b/c\", \"operation\":\"command\", \"name\":\"Status\"}")
+ if not "device" in attr_def["value"]:
+ raise ValueError("Missing device, please use syntax: {\"device\":\"a/b/c\", \"operation\":\"command\", \"name\":\"Status\"}")
+ if not "operation" in attr_def["value"]:
+ raise ValueError("Missing operation, please use syntax: {\"device\":\"a/b/c\", \"operation\":\"command\", \"name\":\"Status\"}")
+ if not "name" in attr_def["value"]:
+ raise ValueError("Missing name, please use syntax: {\"device\":\"a/b/c\", \"operation\":\"command\", \"name\":\"Status\"}")
+ # self.dynamic_attributes[name] = value
+ # self.info_stream("Writing attribute '{name}': {value}")
+ print("Writing attribute ", name, " : ", value)
+
+ def add_dynamic_attribute(self, name, dtype_str, writable):
+ """Dynamically add an attribute to the device."""
+ dtype = TANGO_TYPE_MAPPING.get(dtype_str)
+ if dtype is None:
+ self.error_stream(f"Unsupported Tango data type: {dtype_str}")
+ return
+
+ # Define the attribute using the Attr class
+ attr = Attr(name, dtype, AttrWriteType.READ_WRITE if writable else AttrWriteType.READ)
+
+ # Register the attribute with the device
+ self.add_attribute(attr, self.read_callback, self.write_callback if writable else None)
+
+ # Initialize storage for the attribute value
+ self.dynamic_attributes[name] = None
+
+ # Command to handle JSON requests
+ @command(dtype_in=str, dtype_out=str)
+ def TransformJSON(self, json_request):
+ """
+ Transforms a JSON request into a Tango command or attribute operation.
+ """
+ try:
+ # Parse the JSON request
+ request = json.loads(json_request)
+
+ # Extract details
+ target_device = request.get("device", None)
+ operation = request["operation"] # "command", "attribute", or "dynamic"
+ name = request["name"] # Command or attribute name
+ value = request.get("value") # Optional value for write operations
+
+ if operation == "dynamic":
+ # Handle dynamic attributes
+ if name in self.dynamic_attributes:
+ if value is not None:
+ self.dynamic_attributes[name] = value
+ result = {"status": "success", "message": "Dynamic attribute {name} set to {value}"}
+ else:
+ result = self.dynamic_attributes[name]
+ else:
+ raise KeyError("Dynamic attribute '{name}' not found")
+ else:
+ # Other operations: Command or Attribute
+ target_device = target_device or self.default_tango_device
+ device = tango.DeviceProxy(target_device)
+ if operation == "command":
+ result = device.command_inout(name, value) if value else device.command_inout(name)
+ elif operation == "attribute":
+ if value is not None:
+ # Write attribute
+ device.write_attribute(name, value)
+ result = {"status": "success", "message": "Attribute {name} written successfully"}
+ else:
+ # Read attribute
+ result = device.read_attribute(name).value
+ else:
+ raise ValueError("Invalid operation type. Use 'command', 'attribute', or 'dynamic'.")
+
+ # Format response
+ response = {"status": "success", "result": result}
+ except Exception as e:
+ response = {"status": "error", "message": str(e)}
+
+ return json.dumps(response)
+
+
+# Entry point for the device server
+if __name__ == "__main__":
+ run([JSONGateway])