#31 - WeekdayName parser.

Author: techyian

readme.md

@@ -301,7 +301,7 @@ https://github.com/Apress/beg-sql-server-reporting-services/blob/master/Beginnin
 | Date & Time  | TimeValue       | Complete      |                            |
 | Date & Time  | Today           | Complete      |                            |
 | Date & Time  | Weekday         | Complete      |                            |
-| Date & Time  | WeekdayName     | Not started   |                            |
+| Date & Time  | WeekdayName     | Complete      |                            |
 | Date & Time  | Year            | Not started   |                            |
 
 ### Math

src/ReportViewer.NET/Extensions/DateTimeExtensions.cs

@@ -216,6 +216,11 @@ public static int ParseWeekday(this DateTime dtt, FirstDayOfWeek fdow)
             return currentDayOfWeek + 1;
         }
 
+        public static string ParseWeekdayName(this DateTime dtt, FirstDayOfWeek fdow, bool abbreviate)
+        {            
+            return !abbreviate ? AdjustedWeekdayName(dtt, fdow) : AdjustedWeekdayNameAbbreviated(dtt, fdow);
+        }
+
         public static string FormatDateTime(this DateTime dtt, DateFormat format)
         {
             switch (format)
@@ -298,5 +303,66 @@ private static int AdjustedDayOfWeek(DateTime dtt, FirstDayOfWeek fdow)
                     return (int)calendar.GetDayOfWeek(dtt);
             }
         }
+
+        private static string AdjustedWeekdayName(DateTime dtt, FirstDayOfWeek fdow) 
+        {
+            CultureInfo cultureInfo = CultureInfo.CurrentCulture;
+            Calendar calendar = cultureInfo.Calendar;
+
+            // Using typeof(DayOfWeek) as this is the enum type returned by GetDayOfWeek.
+
+            switch (fdow)
+            {
+                case FirstDayOfWeek.Monday:
+                    return Enum.GetName(typeof(DayOfWeek), AdjustWeekdayBounds((int)calendar.GetDayOfWeek(dtt) + 1));
+                case FirstDayOfWeek.Tuesday:
+                    return Enum.GetName(typeof(DayOfWeek), AdjustWeekdayBounds((int)calendar.GetDayOfWeek(dtt) + 2));
+                case FirstDayOfWeek.Wednesday:
+                    return Enum.GetName(typeof(DayOfWeek), AdjustWeekdayBounds((int)calendar.GetDayOfWeek(dtt) + 3));
+                case FirstDayOfWeek.Thursday:
+                    return Enum.GetName(typeof(DayOfWeek), AdjustWeekdayBounds((int)calendar.GetDayOfWeek(dtt) + 4));
+                case FirstDayOfWeek.Friday:
+                    return Enum.GetName(typeof(DayOfWeek), AdjustWeekdayBounds((int)calendar.GetDayOfWeek(dtt) + 5));
+                case FirstDayOfWeek.Saturday:
+                    return Enum.GetName(typeof(DayOfWeek), AdjustWeekdayBounds((int)calendar.GetDayOfWeek(dtt) + 6));
+                default:
+                    return Enum.GetName(typeof(DayOfWeek), (int)calendar.GetDayOfWeek(dtt));
+            }
+        }       
+
+        private static int AdjustWeekdayBounds(int dayOfWeek)
+        {
+            if (dayOfWeek > 6)
+            {
+                return dayOfWeek -= 7;
+            }
+
+            return dayOfWeek;
+        }
+        
+        private static string AdjustedWeekdayNameAbbreviated(DateTime dtt, FirstDayOfWeek fdow)
+        {
+            var weekdayName = AdjustedWeekdayName(dtt, fdow);
+
+            switch (weekdayName)
+            {
+                case "Sunday":
+                    return "Sun";
+                case "Monday":
+                    return "Mon";
+                case "Tuesday":
+                    return "Tue";
+                case "Wednesday":
+                    return "Wed";
+                case "Thursday":
+                    return "Thu";
+                case "Friday":
+                    return "Fri";
+                case "Saturday":
+                    return "Sat";
+            }
+
+            return string.Empty;
+        }
     }
 }

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

@@ -0,0 +1,89 @@
+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 WeekdayNameParser : BaseParser
+    {
+        public static Regex WeekdayNameRegex = RegexCommon.GenerateMultiParamParserRegex("WeekdayName");
+
+        public WeekdayNameParser(
+            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, WeekdayNameRegex, report)
+        {
+        }
+
+        public override (Type, object) ExtractExpressionValue(string fieldName, string dataSetName)
+        {
+            throw new NotImplementedException();
+        }
+
+        public override void Parse()
+        {
+            var match = WeekdayNameRegex.Match(this.CurrentString);
+            var matchValue = match.Value;
+
+            // Remove the surrounding WeekdayName including open & close brace so we can inspect inner members and see if they too contain program flow expressions. 
+            matchValue = matchValue.MatchValueSubString(12);
+
+            var foundParameters = this.ParseParenthesis(matchValue);
+
+            if (foundParameters.Item2.Count < 1 || foundParameters.Item2.Count > 3)
+            {
+                // The Weekday function expects at least 1 parameter but no more than 3.
+                return;
+            }
+
+            // DateTime will either come directly from database or will be calculated from other expression.
+            var date = this.Report.Parser.ParseReportExpressionString(
+                foundParameters.Item2[0],
+                this.DataSetResults,
+                this.Values,
+                this.CurrentRowNumber,
+                this.DataSets,
+                this.ActiveDataset,
+                null
+            ).ExpressionAsDateTime();
+
+            FirstDayOfWeek fdow = FirstDayOfWeek.System;
+
+            if (foundParameters.Item2.Count == 3)
+            {
+                var fdowString = foundParameters.Item2[2].Trim();
+
+                if (int.TryParse(fdowString, out var fdowInt))
+                {
+                    fdow = (FirstDayOfWeek)fdowInt;
+                }
+                else
+                {
+                    fdow = (FirstDayOfWeek)Enum.Parse(typeof(FirstDayOfWeek), fdowString.Substring(15, fdowString.Length - 15));
+                }
+            }
+
+            this.CurrentExpression.Index = match.Index;
+            this.CurrentExpression.ResolvedType = typeof(string);
+
+            if (foundParameters.Item2.Count == 1 || foundParameters.Item2[1].Trim().EqualsIgnore("false"))
+            {
+                this.CurrentExpression.Value = date.ParseWeekdayName(fdow, false);
+            }
+            else
+            {
+                this.CurrentExpression.Value = date.ParseWeekdayName(fdow, true);
+            }            
+        }
+    }
+}

src/ReportViewer.NET/Parsers/ExpressionFieldOperator.cs

@@ -71,6 +71,7 @@ public enum ExpressionFieldOperator
         TimeValue,
         Today,
         Weekday,
+        WeekdayName,
         FormatCurrency,
         RowNumber
     }

src/ReportViewer.NET/Parsers/ExpressionParser.cs

@@ -650,6 +650,15 @@ ref string proposedString
                 weekdayParser.Parse();
                 proposedString = weekdayParser.GetProposedString();
             }
+
+            if (WeekdayNameParser.WeekdayNameRegex.IsMatch(currentString) &&
+                (currentExpression.Operator == ExpressionFieldOperator.None || WeekdayNameParser.WeekdayNameRegex.Match(currentString).Index < currentExpression.Index)
+            )
+            {
+                var weekdayNameParser = new WeekdayNameParser(currentString, ExpressionFieldOperator.WeekdayName, currentExpression, dataSetResults, values, currentRowNumber, dataSets, activeDataset, _report);
+                weekdayNameParser.Parse();
+                proposedString = weekdayNameParser.GetProposedString();
+            }
         }
 
         private void SearchMathFunctions()

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

@@ -0,0 +1,91 @@
+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 WeekdayNameParserTests
+    {
+        private ExpressionParser _expressionParser;
+        private ReportRDL _report;
+
+        public WeekdayNameParserTests()
+        {
+            var report = TestHelper.PrimeReport();
+
+            _report = report;
+            _expressionParser = new ExpressionParser(report);
+        }
+
+        [TestMethod]
+        public void WeekdayName_Returns_String()
+        {
+            // System defaults first day to Sunday, January 15 2010 is a Friday so we expect Friday to be returned.
+
+            // Arrange
+            var expr = "=WeekdayName(\"January 15, 2010 14:15:30\")";
+
+            // Act
+            var result = _expressionParser.ParseReportExpressionString(
+                expr,
+                null,
+                null,
+                1,
+                _report.DataSets,
+                null,
+                null
+            ).ExpressionAsString();
+
+            // Assert
+            Assert.AreEqual("Friday", result);
+        }
+
+        [TestMethod]
+        public void WeekdayName_Returns_String_First_Day_Tuesday()
+        {
+            // January 15 2010 is a Friday. Setting first day to Tuesday will make this return Sunday as there are 2 days between system default and Tuesday.
+
+            // Arrange
+            var expr = "=WeekdayName(\"January 15, 2010 14:15:30\", False, FirstDayOfWeek.Tuesday)";
+
+            // Act
+            var result = _expressionParser.ParseReportExpressionString(
+                expr,
+                null,
+                null,
+                1,
+                _report.DataSets,
+                null,
+                null
+            ).ExpressionAsString();
+
+            // Assert
+            Assert.AreEqual("Sunday", result);
+        }
+
+        [TestMethod]
+        public void WeekdayName_Returns_String_First_Day_Tuesday_Abbreviated()
+        {
+            // January 15 2010 is a Friday. Setting first day to Tuesday will make this return Sunday as there are 2 days between system default and Tuesday.
+
+            // Arrange
+            var expr = "=WeekdayName(\"January 15, 2010 14:15:30\", True, FirstDayOfWeek.Tuesday)";
+
+            // Act
+            var result = _expressionParser.ParseReportExpressionString(
+                expr,
+                null,
+                null,
+                1,
+                _report.DataSets,
+                null,
+                null
+            ).ExpressionAsString();
+
+            // Assert
+            Assert.AreEqual("Sun", result);
+        }
+    }
+}