Fixed Memento

davidcorne · davidcorne · commit 9d7e5e4e5789 · 2012-08-24T08:34:41.000+01:00
Memento pattern now works as it should, added test to the makefile so
that it can run all the python scripts.
diff --git a/Adapter.py b/Adapter.py
@@ -7,13 +7,6 @@ class Adapter(object):
     def __init__(self):
         print("initalised")
 
-def test(value, message):
-    """ This asserts against the value printing for either pass or fail. """
-    assert value, message
-    print("PASSED: %s" %(message))
-    print("")
-
 #==============================================================================
 if (__name__ == "__main__"):
-    test(True, "This is a passing test")
-    test(False, "This is a failing test")
+    pass
diff --git a/Memento.py b/Memento.py
@@ -1,49 +1,57 @@
 #!/usr/bin/env python
 # Written by: DGC
-# undo
 
 import copy
 
 #==============================================================================
-class something(object):
+class Memento(object):
+
+    def __init__(self, data):
+        # make a deep copy of every variable in the given class
+        for attribute in vars(data):
+            # mechanism for using properties without knowing their names
+            setattr(self, attribute, copy.deepcopy(getattr(data, attribute)))
+
+#==============================================================================
+class Undo(object):
     
     def __init__(self):
-        self.a = 0
-        self.undo_helper = UndoHelper(self)
+        # each instance keeps the latest saved copy so that there is only one 
+        # copy of each in memory
+        self.__last = None
+
+    def save(self):
+        self.__last = Memento(self)
 
     def undo(self):
-        #print("revert %i" %(self.undo_helper.revert().a))
-        self = self.undo_helper.revert()
-        
-    def add(self, number):
-        self.a += number
-        self.undo_helper.append(self)
+        for attribute in vars(self):
+            # mechanism for using properties without knowing their names
+            setattr(self, attribute, getattr(self.__last, attribute))
 
 #==============================================================================
-class UndoHelper(object):
-    
-    def __init__(self, something):
-        self.history = [something]
-
-    def revert(self):
-        #print("revert"),
-        #for i in self.history:
-        #    print(i.a),
-        #    print("")
-        print(self.history)
-        return self.history[0]
+class Data(Undo):
 
-    def append(self, item):
-        self.history.append(copy.deepcopy(item))
+    def __init__(self):
+        super(Data, self).__init__()
+        self.numbers = []
 
 #==============================================================================
 if (__name__ == "__main__"):
-    s = something()
-    s.add(5)
-    print(s.a)
-    s.add(5)
-    print(s.a)
-    s.add(5)
-    print(s.a)
-    s.undo()
-    print(s.a)
+    d = Data()
+    repeats = 10
+    # add a number to the list in data repeat times
+    print("Adding.")
+    for i in range(repeats):
+        print("0" + str(i) + " times: " + str(d.numbers))
+        d.save()
+        d.numbers.append(i)
+    d.save()
+    print("10 times: " + str(d.numbers))
+    print("")
+    
+    # now undo repeat times
+    print("Using Undo.")
+    for i in range(repeats):
+        print("0" + str(i) + " times: " + str(d.numbers))
+        d.undo()
+    print("10 times: " + str(d.numbers))
diff --git a/makefile b/makefile
@@ -1,5 +1,14 @@
 # Targets
 TEX_NAME = Design_Patterns_In_Python
 
+#==============================================================================
+test: FRC
+	@for program in *.py; \
+        do \
+          echo $$program; \
+          ./$$program; \
+          echo ""; \
+        done
+
 include $(DROPBOX)/Coding/MakeFiles/latex.mk
 # override OUTPUT_NAME here
