Add XSSF eventusermodel support

Directory.Packages.props

@@ -14,6 +14,7 @@
     <PackageVersion Include="Microsoft.IO.RecyclableMemoryStream" Version="3.0.1" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.13.0" />
     <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="8.0.0" />
+    <PackageVersion Include="NSax" Version="1.0.2" />
     <PackageVersion Include="NSubstitute" Version="5.1.0" />
     <PackageVersion Include="NuGetizer" Version="1.1.0" />
     <PackageVersion Include="NUnit" Version="4.3.2" />
@@ -26,4 +27,4 @@
     <PackageVersion Include="System.Security.Cryptography.Xml" Version="8.0.2" />
     <PackageVersion Include="ZString" Version="2.6.0" />
   </ItemGroup>
-</Project>
+</Project>

main/HSSF/Extractor/ExcelExtractor.cs

@@ -42,7 +42,7 @@ public class ExcelExtractor : POIOLE2TextExtractor, IExcelExtractor
         private bool formulasNotResults = false;
         private bool includeCellComments = false;
         private bool includeBlankCells = false;
-        private bool includeHeaderFooter = true;
+        private bool includeHeadersFooters = true;
         /// <summary>
         /// Initializes a new instance of the <see cref="ExcelExtractor"/> class.
         /// </summary>
@@ -65,13 +65,13 @@ public ExcelExtractor(POIFSFileSystem fs)
         /// <summary>
         ///  Should header and footer be included? Default is true
         /// </summary>
-        public bool IncludeHeaderFooter
+        public bool IncludeHeadersFooters
         {
             get {
-                return this.includeHeaderFooter;
+                return this.includeHeadersFooters;
             }
             set {
-                this.includeHeaderFooter = value;
+                this.includeHeadersFooters = value;
             }
         }
         /// <summary>
@@ -137,6 +137,8 @@ public bool IncludeBlankCells
             }
         }
 
+        public bool AddTabEachEmptyCell { get; set; }
+
         /// <summary>
         /// Retreives the text contents of the file
         /// </summary>
@@ -168,7 +170,7 @@ public override String Text
                     }
 
                     // Header text, if there is any
-                    if (sheet.Header != null && includeHeaderFooter)
+                    if (sheet.Header != null && includeHeadersFooters)
                     {
                         text.Append(
                                 ExtractHeaderFooter(sheet.Header)
@@ -289,7 +291,7 @@ public override String Text
                     }
 
                     // Finally Feader text, if there is any
-                    if (sheet.Footer != null && includeHeaderFooter)
+                    if (sheet.Footer != null && includeHeadersFooters)
                     {
                         text.Append(
                                 ExtractHeaderFooter(sheet.Footer)

main/SS/Extractor/ExcelExtractor.cs

@@ -27,7 +27,9 @@ public interface IExcelExtractor
         bool IncludeCellComments { get; set; }
         bool IncludeSheetNames { get; set; }
         bool FormulasNotResults { get; set; }
-        bool IncludeHeaderFooter { get; set; }
+        bool IncludeHeadersFooters { get; set; }
+        //Add a tab delimiter for each empty cell.
+        bool AddTabEachEmptyCell { get; set; }
         /**
          * Retreives the text contents of the file
          */

ooxml/NPOI.OOXML.Core.csproj

@@ -13,7 +13,6 @@
     <Compile Remove="POIFS\Crypt\Dsig\KeyInfoKeySelector.cs" />
     <Compile Remove="POIFS\Crypt\Dsig\Services\RelationshipTransformService.cs" />
     <Compile Remove="Properties\AssemblyInfoDotnet2.cs" />
-    <Compile Remove="XSSF\Extractor\XSSFEventBasedExcelExtractor.cs" />
     <Compile Remove="XSSF\UserModel\Charts\XSSFNumberCache.cs" />
   </ItemGroup>
 
@@ -26,6 +25,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="NSax" />
     <PackageReference Include="System.Security.Cryptography.Xml" />
   </ItemGroup>
 

ooxml/POIXMLTextExtractor.cs

@@ -39,21 +39,21 @@ public POIXMLTextExtractor(POIXMLDocument document)
         /**
          * Returns the core document properties
          */
-        public CoreProperties GetCoreProperties()
+        public virtual CoreProperties GetCoreProperties()
         {
             return _document.GetProperties().CoreProperties;
         }
         /**
          * Returns the extended document properties
          */
-        public ExtendedProperties GetExtendedProperties()
+        public virtual ExtendedProperties GetExtendedProperties()
         {
             return _document.GetProperties().ExtendedProperties;
         }
         /**
          * Returns the custom document properties
          */
-        public CustomProperties GetCustomProperties()
+        public virtual CustomProperties GetCustomProperties()
         {
             return _document.GetProperties().CustomProperties;
         }

ooxml/SS/Converter/ExcelToHtmlConverter.cs

@@ -811,7 +811,7 @@ private static void BuildStyle_Border(IWorkbook workbook, StringBuilder style, S
                     var stylesSource = ((XSSFWorkbook) workbook).GetStylesSource();
                     if (stylesSource != null)
                     {
-                        var theme = stylesSource.GetTheme();
+                        var theme = stylesSource.Theme;
                         if (theme != null)
                             color = theme.GetThemeColor(borderColor);
                     }
@@ -853,9 +853,9 @@ private static void BuildStyle_Font(IWorkbook workbook, StringBuilder style, IFo
                 {
                     StylesTable st = ((XSSFWorkbook)workbook).GetStylesSource();
                     XSSFColor fontColor = null;
-                    if (st != null && st.GetTheme() != null)
+                    if (st != null && st.Theme != null)
                     {
-                        fontColor = st.GetTheme().GetThemeColor(font.Color);
+                        fontColor = st.Theme.GetThemeColor(font.Color);
                     }
                     else
                     {