Add document signoff and library book state examples;

1 files changed, 68 insertions, 0 deletions

diff --git a/examples/statemachine/documentSignoffDemo.py b/examples/statemachine/documentSignoffDemo.py
new file mode 100644
index 0000000..9378507
--- /dev/null
+++ b/examples/statemachine/documentSignoffDemo.py
@@ -0,0 +1,68 @@
+#
+# documentSignoffDemo.py
+#
+# Example of a state machine modeling the state of a document in a document
+# control system, using named state transitions
+#
+import statemachine
+import documentsignoffstate
+
+
+class Document:
+    def __init__(self):
+        # start light in Red state
+        self._state = documentsignoffstate.New()
+
+    @property
+    def state(self):
+        return self._state
+
+    # get behavior/properties from current state
+    def __getattr__(self, attrname):
+        attr = getattr(self._state, attrname)
+        if isinstance(getattr(documentsignoffstate, attrname, None),
+                      documentsignoffstate.DocumentRevisionStateTransition):
+            return lambda : setattr(self, '_state', attr())
+        return attr
+
+    def __str__(self):
+        return "{}: {}".format(self.__class__.__name__, self._state)
+
+
+def run_demo():
+    import random
+
+    doc = Document()
+    print(doc)
+
+    # begin editing document
+    doc.create()
+    print(doc)
+    print(doc.state.description)
+
+    while not isinstance(doc._state, documentsignoffstate.Approved):
+
+        print('...submit')
+        doc.submit()
+        print(doc)
+        print(doc.state.description)
+
+        if random.randint(1,10) > 3:
+            print('...reject')
+            doc.reject()
+        else:
+            print('...approve')
+            doc.approve()
+
+        print(doc)
+        print(doc.state.description)
+
+    doc.activate()
+    print(doc)
+    print(doc.state.description)
+
+if __name__ == '__main__':
+    run_demo()
+
+# TODO - can you pickle state or otherwise persist it?
+# TODO - can you decorate state changes (for logging or permission checking)?