Umstieg auf minidom für Kompatibilität

challenge.py

@@ -1,9 +1,12 @@
-""" Mini-Challenge """
+""" Mini-Challenge"""
 
+from os.path import join
+from xml.dom import minidom
 from twisted.internet import defer
 
-class Adapter():
-    """ Adapter class
+
+class Adapter:
+    """Adapter class
 
     Aufgabe: Asynchron XML-Daten lesen, konvertieren und zurückliefern.
     """
@@ -13,23 +16,61 @@ class Adapter():
 
     def retrieve_token(self, name):
         """
-            Retrieve the content from file name.xml in adapters path directory
-            in a synchronous way, extract the DataReceived/Token and return it
-            as a JSON-Object (stringified) '{"token": value}'.
+        Retrieve the content from file name.xml in adapters path directory
+        in a synchronous way, extract the DataReceived/Token and return it
+        as a JSON-Object (stringified) '{"token": value}'.
         """
-        # return '{"token": 42}' - don't do this, just a test
-        raise NotImplementedError
+        try:
+            with open(join(self.path, name + ".xml")) as f:
+                xml_data = f.read()
+                dom = minidom.parseString(xml_data)
+                token = dom.getElementsByTagName("Token")[0].firstChild.data
+
+                return '{"token": %s}' % token
+
+        except Exception as e:
+            raise ValueError("Could not retrieve token: %s" % e)
 
     def retrieve_token_async(self, name):
         """
-            Retrieve the content from file name.xml in adapters path directory
-            in an asynchronous way, extract the DataReceived/Token and return it
-            as a Deferred which ends up in a JSON-Object (as above).
+        Retrieve the content from file name.xml in adapters path directory
+        in an asynchronous way, extract the DataReceived/Token and return it
+        as a Deferred which ends up in a JSON-Object (as above).
 
-            see: https://twistedmatrix.com/documents/8.0.0/api/twisted.internet.defer.Deferred.html
+        see: https://twistedmatrix.com/documents/8.0.0/api/twisted.internet.defer.Deferred.html
 
-            Hint: The simple way is to use defer.succeed(), bonus points for doing
-                  it with a callback chain read->parse->convert.
+        Hint: The simple way is to use defer.succeed(), bonus points for doing
+              it with a callback chain read->parse->convert.
         """
-        #return defer.succeed('{"token": 42}') - don't do this, just a test
-        raise NotImplementedError
+        d = defer.Deferred()
+
+        def read_file():
+            try:
+                with open(join(self.path, name + ".xml")) as f:
+                    xml_data = f.read()
+                    return xml_data
+            except Exception as e:
+                d.errback(e)
+
+        def parse_xml(xml_data):
+            try:
+                dom = minidom.parseString(xml_data)
+                token = dom.getElementsByTagName("Token")[0].firstChild.data
+
+                return token
+
+            except Exception as e:
+                d.errback(e)
+
+        def convert_to_json(token):
+            try:
+                json_string = '{"token": %s}' % token
+                d.callback(json_string)
+            except Exception as e:
+                d.errback(e)
+
+        defer.execute(read_file).addCallback(parse_xml).addCallback(
+            convert_to_json
+        ).addErrback(d.errback)
+
+        return d