From 4bf4444d817722408d322c969c27a9a7c6ea8bde Mon Sep 17 00:00:00 2001
From: "Zheng, Lei" <realthunder.dev@gmail.com>
Date: Mon, 30 Sep 2019 13:41:01 +0800
Subject: [PATCH] App: add DocumentObjectPy.evalExpression()

Allow easy evlauation of expression.
---
 src/App/DocumentObjectPy.xml    |  5 +++++
 src/App/DocumentObjectPyImp.cpp | 14 ++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/src/App/DocumentObjectPy.xml b/src/App/DocumentObjectPy.xml
index 50633d38bb..288f351214 100644
--- a/src/App/DocumentObjectPy.xml
+++ b/src/App/DocumentObjectPy.xml
@@ -55,6 +55,11 @@
                 <UserDocu>Register an expression for a property</UserDocu>
             </Documentation>
         </Methode>
+        <Methode Name="evalExpression">
+            <Documentation>
+                <UserDocu>Evaluate an expression</UserDocu>
+            </Documentation>
+        </Methode>
         <Methode Name="recompute">
             <Documentation>
                 <UserDocu>recompute(recursive=False): Recomputes this object</UserDocu>
diff --git a/src/App/DocumentObjectPyImp.cpp b/src/App/DocumentObjectPyImp.cpp
index 182d6bc520..5da0b636d7 100644
--- a/src/App/DocumentObjectPyImp.cpp
+++ b/src/App/DocumentObjectPyImp.cpp
@@ -368,6 +368,20 @@ PyObject*  DocumentObjectPy::setExpression(PyObject * args)
     Py_Return;
 }
 
+PyObject*  DocumentObjectPy::evalExpression(PyObject * args)
+{
+    const char *expr;
+    if (!PyArg_ParseTuple(args, "s", &expr))     // convert args: Python->C
+        return NULL;                    // NULL triggers exception
+
+    PY_TRY {
+        boost::shared_ptr<Expression> shared_expr(Expression::parse(getDocumentObjectPtr(), expr));
+        if(shared_expr)
+            return Py::new_reference_to(shared_expr->getPyValue());
+        Py_Return;
+    } PY_CATCH
+}
+
 PyObject*  DocumentObjectPy::recompute(PyObject *args)
 {
     PyObject *recursive=Py_False;