Export ArrayLengthValidator to Python. Refs #4399

Code/Mantid/Framework/PythonInterface/CMakeLists.txt

@@ -78,6 +78,7 @@ set ( TEST_PY_FILES
   test/python/AlgorithmManagerTest.py
   test/python/AnalysisDataServiceTest.py
   test/python/ArrayPropertyTest.py
+  test/python/ArrayLengthValidatorTest.py
   test/python/AxisTest.py
   test/python/BoundedValidatorTest.py
   test/python/ConfigServiceTest.py

Code/Mantid/Framework/PythonInterface/mantid/kernel/CMakeLists.txt

@@ -27,6 +27,7 @@ set ( EXPORT_FILES
   src/Exports/FacilityInfo.cpp
   src/Exports/NullValidator.cpp
   src/Exports/ListValidator.cpp
+  src/Exports/ArrayLengthValidator.cpp
 )  
 
 set ( SRC_FILES

Code/Mantid/Framework/PythonInterface/mantid/kernel/src/Exports/ArrayLengthValidator.cpp

@@ -0,0 +1,27 @@
+#include "MantidKernel/ArrayLengthValidator.h"
+#include <boost/python/class.hpp>
+
+using Mantid::Kernel::ArrayLengthValidator;
+using Mantid::Kernel::IValidator;
+using namespace boost::python;
+
+namespace
+{
+
+  #define EXPORT_LENGTHVALIDATOR(type, prefix) \
+    class_<ArrayLengthValidator<type>, bases<IValidator>, \
+           boost::noncopyable \
+          >(#prefix"ArrayLengthValidator") \
+      .def(init<int>(arg("length"), "Constructs a validator verifying that an array is of the exact length given"))\
+      .def(init<int,int>((arg("lenmin"),arg("lenmax")), "Constructs a validator verifying that the length of an array is within the range given"))\
+    ;
+
+}
+
+void export_ArrayLengthValidator()
+{
+  EXPORT_LENGTHVALIDATOR(double, Float);
+  EXPORT_LENGTHVALIDATOR(int, Int);
+  EXPORT_LENGTHVALIDATOR(std::string, String);
+}
+

Code/Mantid/Framework/PythonInterface/test/python/ArrayLengthValidatorTest.py

@@ -0,0 +1,66 @@
+import unittest
+import testhelpers
+
+from mantid import FloatArrayLengthValidator, PythonAlgorithm, FloatArrayProperty
+
+class ArrayLengthValidatorTest(unittest.TestCase):
+
+    def test_Validator_on_ArrayProperty_accepts_array_of_specified_length(self):
+        fixedlength = 6
+        alg = self._create_alg_with_fixedlength_validator(fixedlength)
+        input_vals = [1.,2.4,5.6,8.0,4.6,6.]
+        testhelpers.assertRaisesNothing(self, alg.setProperty, "Input", input_vals)
+
+    def test_Validator_on_ArrayProperty_rejects_array_of_without_correct_length(self):
+        fixedlength = 6
+        alg = self._create_alg_with_fixedlength_validator(fixedlength)
+        input_vals = [1.,2.4,5.6]
+        self.assertRaises(ValueError, alg.setProperty, "Input", input_vals)
+
+    def test_Validator_on_ArrayProperty_accepts_array_with_length_in_range(self):
+        alg = self._create_alg_with_range_validator(3,5)
+        input_vals = []
+        for i in range(1,7):
+            input_vals.append(float(1))
+            if i < 3 or i > 5:
+                self.assertRaises(ValueError, alg.setProperty, "Input", input_vals)
+            else:
+                testhelpers.assertRaisesNothing(self, alg.setProperty, "Input", input_vals)
+
+    def _create_alg_with_fixedlength_validator(self, fixedlength):
+        """
+            Creates a test algorithm with a fixed length validator
+        """
+        class TestAlgorithm(PythonAlgorithm):
+
+            def PyInit(self):
+                validator = FloatArrayLengthValidator(fixedlength)
+                self.declareProperty(FloatArrayProperty("Input", validator))
+
+            def PyExec(self):
+                pass
+
+        alg = TestAlgorithm()
+        alg.initialize()
+        return alg
+
+    def _create_alg_with_range_validator(self, minlength, maxlength):
+        """
+            Creates a test algorithm with a range length validator
+        """
+        class TestAlgorithm(PythonAlgorithm):
+
+            def PyInit(self):
+                validator = FloatArrayLengthValidator(minlength, maxlength)
+                self.declareProperty(FloatArrayProperty("Input", validator))
+
+            def PyExec(self):
+                pass
+
+        alg = TestAlgorithm()
+        alg.initialize()
+        return alg
+
+
+if __name__ == '__main__':
+    unittest.main()