Implemented Length function

Author: Florian Krönert

build.fsx

@@ -35,7 +35,7 @@ let sha = Git.Information.getCurrentHash()
 // version info
 let major = "3"
 let minor = "9"
-let patch = "6"
+let patch = "7"
 
 // Follow SemVer scheme: http://semver.org/
 let asmVersion = major + "." + minor + "." + patch

src/lib/Xrm.Oss.XTL.Interpreter/FunctionHandlers.cs

@@ -427,6 +427,27 @@ private static int Compare(List<ValueExpression> parameters)
             return new ValueExpression(string.Join(", ", mappedValues.Select(p => p.Text)), mappedValues);
         };
 
+        public static FunctionHandler Length = (primary, service, tracing, organizationConfig, parameters) =>
+        {
+            if (parameters.Count < 1)
+            {
+                throw new InvalidPluginExecutionException("Length function needs at least an array or a string as input");
+            }
+
+            var config = GetConfig(parameters);
+
+            var values = parameters[0]?.Value as List<ValueExpression>;
+
+            if (values is IEnumerable)
+            {
+                return new ValueExpression(values.Count.ToString(), values.Count);
+            }
+
+            var stringValue = CheckedCast<string>(parameters[0]?.Value, "Parameter of length function must be either an array or a string");
+
+            return new ValueExpression(stringValue.Length.ToString(), stringValue.Length.ToString());
+        };
+
         public static FunctionHandler Filter = (primary, service, tracing, organizationConfig, parameters) =>
         {
             if (parameters.Count < 2)

src/lib/Xrm.Oss.XTL.Interpreter/XTLInterpreter.cs

@@ -48,6 +48,7 @@ public class XTLInterpreter
             { "IsNull", FunctionHandlers.IsNull },
             { "Join", FunctionHandlers.Join },
             { "Last", FunctionHandlers.Last},
+            { "Length", FunctionHandlers.Length },
             { "Map", FunctionHandlers.Map },
             { "NewLine", FunctionHandlers.NewLine },
             { "Not", FunctionHandlers.Not },

src/test/Xrm.Oss.XTL.Interpreter.Tests/XTLInterpreterTests.cs

@@ -1055,6 +1055,34 @@ public void It_Should_Parse_Dictionaries()
             Assert.That(result, Is.EqualTo("retrieveLabels: True, returnOptionSetValue: False"));
         }
 
+        [Test]
+        public void It_Should_Count_Length_Of_Arrays()
+        {
+            var context = new XrmFakedContext();
+            var service = context.GetFakedOrganizationService();
+            var tracing = context.GetFakeTracingService();
+
+            var formula = "Length( [ \"A\", \"B\", \"C\" ] )";
+
+            var result = new XTLInterpreter(formula, null, null, service, tracing).Produce();
+
+            Assert.That(result, Is.EqualTo("3"));
+        }
+
+        [Test]
+        public void It_Should_Count_Length_Of_String()
+        {
+            var context = new XrmFakedContext();
+            var service = context.GetFakedOrganizationService();
+            var tracing = context.GetFakeTracingService();
+
+            var formula = "Length( \"ABC\" )";
+
+            var result = new XTLInterpreter(formula, null, null, service, tracing).Produce();
+
+            Assert.That(result, Is.EqualTo("3"));
+        }
+
         [Test]
         public void It_Should_Not_Fail_On_Complex_Template_Field()
         {