#35 - CDate parser.

Author: techyian

readme.md

@@ -279,7 +279,7 @@ https://github.com/Apress/beg-sql-server-reporting-services/blob/master/Beginnin
 
 | Group | Expression     | Status        | Comments                   |
 | ----- | -------        | ------        | --------                   |
-| Date & Time  | CDate           | Not started   |                            |
+| Date & Time  | CDate           | Complete      |                            |
 | Date & Time  | DateAdd         | Complete      |                            |
 | Date & Time  | DateDiff        | Complete      |                            |
 | Date & Time  | DatePart        | Partial       | Not yet tested with all time intervals                            |

src/ReportViewer.NET/Parsers/DateAndTime/CDateParser.cs

@@ -0,0 +1,57 @@
+using Microsoft.VisualBasic;
+using ReportViewer.NET.DataObjects;
+using ReportViewer.NET.Extensions;
+using System;
+using System.Collections.Generic;
+using System.Text.RegularExpressions;
+
+namespace ReportViewer.NET.Parsers.DateAndTime
+{
+    public class CDateParser : BaseParser
+    {
+        public static Regex CDateRegex = RegexCommon.GenerateParserRegex("CDate");
+
+        public CDateParser(
+            string currentString,
+            ExpressionFieldOperator op,
+            ReportExpression currentExpression,
+            IEnumerable<IDictionary<string, object>> dataSetResults,
+            IDictionary<string, object> values,
+            int currentRowNumber,
+            IEnumerable<DataSet> dataSets,
+            DataSet activeDataset,
+            ReportRDL report
+        ) : base(currentString, op, currentExpression, dataSetResults, values, currentRowNumber, dataSets, activeDataset, CDateRegex, report)
+        {
+        }
+
+        public override (Type, object) ExtractExpressionValue(string fieldName, string dataSetName)
+        {
+            throw new NotImplementedException();
+        }
+
+        public override void Parse()
+        {
+            var match = CDateRegex.Match(CurrentString);
+            var matchValue = match.Value;
+
+            // Remove the surrounding CDate including open & close brace so we can inspect inner members and see if they too contain program flow expressions. 
+            matchValue = matchValue.MatchValueSubString(6);
+
+            // DateTime will either come directly from database or will be calculated from other expression.
+            var date = this.Report.Parser.ParseReportExpressionString(
+                matchValue,
+                this.DataSetResults,
+                this.Values,
+                this.CurrentRowNumber,
+                this.DataSets,
+                this.ActiveDataset,
+                null
+            ).ExpressionAsDateTime();
+
+            this.CurrentExpression.Index = match.Index;
+            this.CurrentExpression.ResolvedType = typeof(DateTime);                                       
+            this.CurrentExpression.Value = date;
+        }
+    }
+}

src/ReportViewer.NET/Parsers/DateAndTime/DateStringParser.cs

@@ -1,11 +1,7 @@
 using ReportViewer.NET.DataObjects;
-using ReportViewer.NET.Extensions;
 using System;
 using System.Collections.Generic;
-using System.Linq;
-using System.Text;
 using System.Text.RegularExpressions;
-using System.Threading.Tasks;
 
 namespace ReportViewer.NET.Parsers.DateAndTime
 {

src/ReportViewer.NET/Parsers/ExpressionFieldOperator.cs

@@ -53,6 +53,7 @@ public enum ExpressionFieldOperator
         OrElse,
         Left,
         MonthName,
+        CDate,
         DateAdd,
         DateDiff,
         DatePart,

src/ReportViewer.NET/Parsers/ExpressionParser.cs

@@ -479,6 +479,15 @@ private void SearchDateTimeFunctions(
             ref string proposedString
         )
         {
+            if (CDateParser.CDateRegex.IsMatch(currentString) &&
+                (currentExpression.Operator == ExpressionFieldOperator.None || CDateParser.CDateRegex.Match(currentString).Index < currentExpression.Index)
+            )
+            {
+                var cDateParser = new CDateParser(currentString, ExpressionFieldOperator.CDate, currentExpression, dataSetResults, values, currentRowNumber, dataSets, activeDataset, _report);
+                cDateParser.Parse();
+                proposedString = cDateParser.GetProposedString();
+            }
+
             if (MonthNameParser.MonthNameRegex.IsMatch(currentString) &&
                 (currentExpression.Operator == ExpressionFieldOperator.None || MonthNameParser.MonthNameRegex.Match(currentString).Index < currentExpression.Index)
             )

test/ReportViewer.NET.Tests/Parsers/DateAndTime/CDateParserTests.cs

@@ -0,0 +1,65 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using ReportViewer.NET.DataObjects;
+using ReportViewer.NET.Extensions;
+using ReportViewer.NET.Parsers;
+
+namespace ReportViewer.NET.Tests.Parsers.DateAndTime
+{
+    [TestClass]
+    public class CDateParserTests
+    {
+        private ExpressionParser _expressionParser;
+        private ReportRDL _report;
+
+        public CDateParserTests()
+        {
+            var report = TestHelper.PrimeReport();
+
+            _report = report;
+            _expressionParser = new ExpressionParser(report);
+        }
+
+        [TestMethod]
+        public void CDate_From_Date_Returns_Date()
+        {
+            // Arrange
+            var expr = "=CDate(Now())";
+
+            // Act
+            var result = _expressionParser.ParseReportExpressionString(
+                expr,
+                null,
+                null,
+                1,
+                _report.DataSets,
+                null,
+                null
+            ).ExpressionAsDateTime();
+
+            // Assert
+            Assert.AreEqual(DateTime.Now.Hour, result.Hour);
+            Assert.AreEqual(DateTime.Now.Minute, result.Minute);
+        }
+
+        [TestMethod]
+        public void CDate_From_String_Returns_Date()
+        {
+            // Arrange
+            var expr = "=CDate(\"January 15, 2010\")";
+
+            // Act
+            var result = _expressionParser.ParseReportExpressionString(
+                expr,
+                null,
+                null,
+                1,
+                _report.DataSets,
+                null,
+                null
+            ).ExpressionAsDateTime();
+
+            // Assert
+            Assert.AreEqual(new DateTime(2010, 1, 15), result);            
+        }
+    }
+}