Merge pull request #94 from sartography/master

A year of BPMN / DMN Enhancements

.gitignore

@@ -8,3 +8,5 @@ nosetests.xml
 .coverage
 tests/coverage.xml
 .c9revisions
+.idea
+/venv

.travis.yml

@@ -1,10 +1,8 @@
 language: python
 python:
-  - "2.7"
-  - "3.3"
-  - "3.4"
-  - "3.5"
   - "3.6"
+  - "3.7"
+  - "3.8"
 install:
   - "pip install -r requirements.txt"
   - "pip install celery"

AUTHORS

@@ -1,3 +1,5 @@
 Samuel Abels <http://github.com/knipknap/>
 Ziad Sawalha <http://github.com/ziadsawalha/>
 Matthew Hampton <http://github.com/matthewhampton/>
+Kelly McDonald
+Dan Funk

CONTRIB

@@ -8,7 +8,7 @@ Coding style:
 Testing:
 
   Non-public classes and methods MUST be prefixed by _. This is also important
-  because the test and API documentation machinery makes assumtions based on
+  because the test and API documentation machinery makes assumptions based on
   this convention.
 
   Every added public class MUST have a corresponding unit test. The tests are

Dockerfile

@@ -1,4 +1,4 @@
-FROM python:2-wheezy
+FROM python:3.6
 RUN apt-get -y update && apt-get upgrade -yu
 COPY . /tmp/SpiffWorkflow
 RUN cd /tmp/SpiffWorkflow && make wheel && pip install dist/SpiffWorkflow*.whl

SpiffWorkflow/__init__.py

@@ -5,6 +5,12 @@
 from .workflow import Workflow
 from .task import Task
 from .exceptions import WorkflowException
+from .navigation import NavItem
+from .bpmn.specs.BpmnSpecMixin import BpmnSpecMixin, SequenceFlow
+from .bpmn.specs.UnstructuredJoin import UnstructuredJoin
+from .bpmn.specs.MultiInstanceTask import MultiInstanceTask
+from .bpmn.specs.CallActivity import CallActivity
+from .bpmn.specs.BoundaryEvent import _BoundaryEventParent
 
 import inspect
 __all__ = [name for name, obj in list(locals().items())

SpiffWorkflow/bpmn/BpmnFeelScriptEngine.py

@@ -0,0 +1,55 @@
+# -*- coding: utf-8 -*-
+from __future__ import division, absolute_import
+from builtins import object
+# Copyright (C) 2012 Matthew Hampton
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301  USA
+from SpiffWorkflow.exceptions import WorkflowTaskExecException
+
+from .FeelLikeScriptEngine import FeelLikeScriptEngine
+from ..operators import Operator
+
+
+class BpmnFeelScriptEngine(FeelLikeScriptEngine):
+    """
+    Used during execution of a BPMN workflow to evaluate condition / value
+    expressions. These are used by Gateways, and by Catching Events
+    (non-message ones).
+
+    Also used to execute scripts.
+
+    If you are uncomfortable with the use of eval() and exec, then you should
+    provide a specialised subclass that parses and executes the scripts /
+    expressions in a mini-language of your own.
+    """
+
+    def evaluate(self, task, expression):
+        """
+        Evaluate the given expression, within the context of the given task and
+        return the result.
+        """
+        try:
+            if isinstance(expression, Operator):
+                # I am assuming that this takes care of some kind of XML
+                # expression judging from the contents of operators.py
+                return expression._matches(task)
+            else:
+                return super().evaluate(expression, **task.data)
+        except Exception as e:
+            raise WorkflowTaskExecException(task,
+                                            "Error evaluating expression "
+                                            "'%s', %s" % (expression, str(e)))
+

SpiffWorkflow/bpmn/BpmnScriptEngine.py

@@ -17,11 +17,13 @@
 # License along with this library; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 # 02110-1301  USA
+from SpiffWorkflow.exceptions import WorkflowTaskExecException
 
+from .PythonScriptEngine import PythonScriptEngine
 from ..operators import Operator
 
 
-class BpmnScriptEngine(object):
+class BpmnScriptEngine(PythonScriptEngine):
     """
     Used during execution of a BPMN workflow to evaluate condition / value
     expressions. These are used by Gateways, and by Catching Events
@@ -39,18 +41,15 @@ def evaluate(self, task, expression):
         Evaluate the given expression, within the context of the given task and
         return the result.
         """
-        if isinstance(expression, Operator):
-            return expression._matches(task)
-        else:
-            return self._eval(task, expression, **task.data)
+        try:
+            if isinstance(expression, Operator):
+                # I am assuming that this takes care of some kind of XML
+                # expression judging from the contents of operators.py
+                return expression._matches(task)
+            else:
+                return super().evaluate(expression, **task.data)
+        except Exception as e:
+            raise WorkflowTaskExecException(task,
+                                            "Error evaluating expression "
+                                            "'%s', %s" % (expression, str(e)))
 
-    def execute(self, task, script, **kwargs):
-        """
-        Execute the script, within the context of the specified task
-        """
-        locals().update(kwargs)
-        exec(script)
-
-    def _eval(self, task, expression, **kwargs):
-        locals().update(kwargs)
-        return eval(expression)

SpiffWorkflow/bpmn/DMNPythonScriptEngine.py

@@ -0,0 +1,81 @@
+# -*- coding: utf-8 -*-
+from builtins import object
+import ast
+import re
+import operator
+import datetime
+from datetime import timedelta
+from decimal import Decimal
+from SpiffWorkflow.workflow import WorkflowException
+from .PythonScriptEngine import PythonScriptEngine, Box
+
+# Copyright (C) 2020 Kelly McDonald
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301  USA
+
+class DMNPythonScriptEngine(PythonScriptEngine):
+    """
+    This simply overrides the python script engine to do some specific things for
+    DMN - I left the underlying PythonScriptEngine with everything in place so it
+    will play nice with the existing FeelLikeScriptEngine
+    """
+    def __init__(self):
+        super().__init__()
+
+    def eval_dmn_expression(self, inputExpr, matchExpr, **kwargs):
+        """
+        Here we need to handle a few things such as if it is an equality or if
+        the equality has already been taken care of. For now, we just assume it is equality.
+        """
+
+
+
+        if matchExpr is None:
+            return True
+
+        nolhs = False
+        if '?' in matchExpr:
+            nolhs = True
+            matchExpr = matchExpr.replace('?', 'dmninputexpr')
+
+        rhs, needsEquals = self.validateExpression(matchExpr)
+
+        extra = {
+            'datetime': datetime,
+            'timedelta': timedelta,
+            'Decimal': Decimal,
+            'Box': Box
+        }
+
+        lhs, lhsNeedsEquals = self.validateExpression(inputExpr)
+        if not lhsNeedsEquals:
+            raise WorkflowException("Input Expression '%s' is malformed"%inputExpr)
+        if nolhs:
+            dmninputexpr = self.evaluate(lhs, external_methods= extra, **kwargs)
+            extra = {'dmninputexpr':dmninputexpr,
+                     'datetime':datetime,
+                     'timedelta':timedelta,
+                     'Decimal':Decimal,
+                     'Box':Box
+            }
+            return self.evaluate(rhs,external_methods=extra, **kwargs)
+        if needsEquals:
+           expression = lhs + ' == ' + rhs
+        else:
+            expression = lhs + rhs
+
+        return self.evaluate(expression, external_methods=extra, **kwargs)
+