updating ua file for more user control

asyncua/client/ua_file.py

@@ -4,33 +4,37 @@ class UaFile:
     def __init__(self, file_node):
         self._file_node = file_node
 
-    async def read_file(self):
-        """
-        :param file_node: node of file object (e.g. node = client.get_node("ns=2;s=nameOfNode")
-        """
-        handle = await self._open_file(ua.OpenFileMode.Read.value)
-        size = await self._get_file_size()
-
-        read_node = await self._file_node.get_child("Read")
-        arg1 = ua.Variant(handle, ua.VariantType.UInt32)
-        arg2 = ua.Variant(size, ua.VariantType.Int32)
-        contents = await self._file_node.call_method(read_node, arg1, arg2)
-        await self._close_file(handle)
-        return contents
-
-    async def _open_file(self, open_mode):
+    async def open(self, open_mode):
         """ open file method """
         open_node = await self._file_node.get_child("Open")
         arg = ua.Variant(open_mode, ua.VariantType.Byte)
         return await self._file_node.call_method(open_node, arg)
 
-    async def _get_file_size(self):
+    async def get_size(self):
         """ gets size of file """
         size_node = await self._file_node.get_child("Size")
         return await size_node.read_value()
 
-    async def _close_file(self, handle):
+    async def close(self, handle):
         """ close file method """
         read_node = await self._file_node.get_child("Close")
         arg1 = ua.Variant(handle, ua.VariantType.UInt32)
         return await self._file_node.call_method(read_node, arg1)
+
+    async def read(self, handle, size):
+        """
+        :param handle: handle from open()
+        :param size: size of file from from get_size()
+        """
+        read_node = await self._file_node.get_child("Read")
+        arg1 = ua.Variant(handle, ua.VariantType.UInt32)
+        arg2 = ua.Variant(size, ua.VariantType.Int32)
+        return await self._file_node.call_method(read_node, arg1, arg2)
+
+    async def read_once(self):
+        """ open, read, close in one operation """
+        handle = await self.open(ua.OpenFileMode.Read.value)
+        size = await self.get_size()
+        contents = await self.read(handle, size)
+        await self.close(handle)
+        return contents

examples/client-file.py

@@ -1,4 +1,5 @@
 import asyncio
+from asyncua import ua
 from asyncua.client import Client
 from asyncua.client.ua_file import UaFile
 
@@ -9,7 +10,17 @@ async def read_file():
     async with Client(url=url) as client:
         file_node = client.get_node("ns=2;s=NameOfNode")
         ua_file_client = UaFile(file_node)
-        contents = await ua_file_client.read_file()
+
+        # open(), read(), close() all in one operation
+        contents = await ua_file_client.read_once()
+        print(contents)
+
+        # handling all methods by the user
+        handle = await ua_file_client.open(ua.OpenFileMode.Read.value)
+        size = await ua_file_client.get_size()
+        contents = await ua_file_client.read(handle, size)
+        await ua_file_client.close(handle)
         print(contents)
 
+
 asyncio.run(read_file())