Made stats plugin write its own XML attribute file

malcolm/includes/ADCore/ndarray_parts.yaml

@@ -27,3 +27,9 @@
     description: Current unique id number for frame
     rbv: $(prefix):UniqueId_RBV
     widget: textupdate
+
+- parts.ca.CACharArrayPart:
+    name: attributesFile
+    description: Filename for NDAttributes
+    pv: $(prefix):NDAttributesFile
+    widget: textinput

malcolm/parts/ADCore/statspluginpart.py

@@ -1,3 +1,9 @@
+import os
+from xml.etree import cElementTree as ET
+
+from malcolm.compat import et_to_string
+from malcolm.core import REQUIRED, method_takes
+from malcolm.core.vmetas import StringMeta
 from malcolm.parts.builtin.childpart import ChildPart
 from malcolm.controllers.runnablecontroller import RunnableController
 from malcolm.parts.ADCore.hdfwriterpart import CalculatedNDAttributeDatasetInfo
@@ -9,8 +15,27 @@ class StatsPluginPart(ChildPart):
     def report_info(self, _):
         return [CalculatedNDAttributeDatasetInfo(name="sum", attr="StatsTotal")]
 
+    def _make_attributes_xml(self):
+        # Make a root element with an NXEntry
+        root_el = ET.Element("Attributes")
+        ET.SubElement(
+            root_el, "Attribute", addr="0", datatype="DOUBLE", type="PARAM",
+            description="Sum of the array", name="StatsTotal", source="TOTAL",
+        )
+        xml = et_to_string(root_el)
+        return xml
+
     @RunnableController.Configure
-    def configure(self, task, completed_steps, steps_to_do, part_info):
-        task.put_many(self.child, dict(
+    @method_takes(
+        "filePath", StringMeta("File path to write data to"), REQUIRED)
+    def configure(self, task, completed_steps, steps_to_do, part_info, params):
+        file_dir, filename = params.filePath.rsplit(os.sep, 1)
+        fs = task.put_many_async(self.child, dict(
             enableCallbacks=True,
             computeStatistics=True))
+        xml = self._make_attributes_xml()
+        attributes_filename = os.path.join(
+            file_dir, "%s-attributes.xml" % self.params.mri)
+        open(attributes_filename, "w").write(xml)
+        fs += task.put_async(self.child["attributesFile"], attributes_filename)
+        task.wait_all(fs)

tests/test_parts/test_ADCore/test_statspluginpart.py

@@ -21,18 +21,38 @@ def getitem(name):
         self.child.__getitem__.side_effect = getitem
 
         self.params = MagicMock()
+        self.params.mri = "BLOCK-STAT"
         self.process.get_block.return_value = self.child
         self.o = StatsPluginPart(self.process, self.params)
 
+    def test_report_info(self):
+        infos = self.o.report_info(ANY)
+        self.assertEqual(len(infos), 1)
+        self.assertEqual(infos[0].name, "sum")
+        self.assertEqual(infos[0].attr, "StatsTotal")
+
     def test_configure(self):
         task = MagicMock()
         completed_steps = ANY
         steps_to_do = ANY
         part_info = ANY
-        self.o.configure(task, completed_steps, steps_to_do, part_info)
-        task.put_many.assert_called_once_with(self.child, dict(
+        params = MagicMock()
+        params.filePath = "/tmp/anything.h5"
+        infos = self.o.configure(
+            task, completed_steps, steps_to_do, part_info, params)
+        self.assertIsNone(infos)
+        task.put_many_async.assert_called_once_with(self.child, dict(
             enableCallbacks=True,
             computeStatistics=True))
+        expected_filename = "/tmp/BLOCK-STAT-attributes.xml"
+        task.put_async.assert_called_once_with(
+            self.child["attributesFile"], expected_filename)
+        expected_xml = """<?xml version="1.0" ?>
+<Attributes>
+<Attribute addr="0" datatype="DOUBLE" description="Sum of the array" name="StatsTotal" source="TOTAL" type="PARAM" />
+</Attributes>"""
+        actual_xml = open(expected_filename).read().replace(">", ">\n")
+        self.assertEqual(actual_xml.splitlines(), expected_xml.splitlines())
 
 if __name__ == "__main__":
     unittest.main(verbosity=2)