Add per-sheet filtering to ExcelToPdfConverter (SheetIndices / SheetNames)

README.md

@@ -86,6 +86,27 @@ var doc = ExcelToPdfConverter.Convert("data.xlsx", options);
 doc.Save("data.pdf");
 ```
 
+### Multi-Sheet Handling
+
+By default all sheets are converted. Use `SheetIndices` (zero-based) or `SheetNames` (case-insensitive) to select a subset:
+
+```csharp
+// Convert only the first and third sheet (by index)
+var options = new ExcelToPdfConverter.ConversionOptions
+{
+    SheetIndices = new[] { 0, 2 },
+};
+
+// Convert only sheets named "Sales" and "Summary" (case-insensitive)
+var options2 = new ExcelToPdfConverter.ConversionOptions
+{
+    SheetNames = new[] { "Sales", "Summary" },
+};
+```
+
+When both `SheetIndices` and `SheetNames` are specified, `SheetIndices` takes precedence.
+```
+
 ### Save to Stream or Byte Array
 
 ```csharp

src/MiniPdf/ExcelToPdfConverter.cs

@@ -42,6 +42,17 @@ public sealed class ConversionOptions
 
         /// <summary>Whether to include sheet name as a header (default: true).</summary>
         public bool IncludeSheetName { get; set; } = true;
+
+        /// <summary>
+        /// Zero-based indices of the sheets to include. When null or empty, all sheets are included.
+        /// </summary>
+        public IReadOnlyList<int>? SheetIndices { get; set; }
+
+        /// <summary>
+        /// Names of the sheets to include (case-insensitive). When null or empty, all sheets are included.
+        /// Ignored if <see cref="SheetIndices"/> is also specified.
+        /// </summary>
+        public IReadOnlyList<string>? SheetNames { get; set; }
     }
 
     /// <summary>
@@ -68,7 +79,20 @@ public static PdfDocument Convert(Stream excelStream, ConversionOptions? options
         var sheets = ExcelReader.ReadSheets(excelStream);
         var doc = new PdfDocument();
 
-        foreach (var sheet in sheets)
+        // Filter sheets by index or name if specified
+        IEnumerable<ExcelSheet> sheetsToRender = sheets;
+        if (options.SheetIndices is { Count: > 0 })
+        {
+            var indexSet = new HashSet<int>(options.SheetIndices);
+            sheetsToRender = sheets.Where((_, i) => indexSet.Contains(i));
+        }
+        else if (options.SheetNames is { Count: > 0 })
+        {
+            var nameSet = new HashSet<string>(options.SheetNames, StringComparer.OrdinalIgnoreCase);
+            sheetsToRender = sheets.Where(s => nameSet.Contains(s.Name));
+        }
+
+        foreach (var sheet in sheetsToRender)
         {
             RenderSheet(doc, sheet, options);
         }

tests/MiniPdf.Tests/ExcelToPdfConverterTests.cs

@@ -127,6 +127,83 @@ public void Convert_WithTextColor_PreservesColorInPdf()
         Assert.Contains("0.000 0.000 1.000 rg", content);
     }
 
+    [Fact]
+    public void Convert_WithSheetIndices_OnlyRendersSpecifiedSheets()
+    {
+        using var excelStream = CreateMultiSheetExcel(
+            ("Alpha", new[] { new[] { "AlphaCell" } }),
+            ("Beta",  new[] { new[] { "BetaCell"  } }),
+            ("Gamma", new[] { new[] { "GammaCell" } }));
+
+        var options = new ExcelToPdfConverter.ConversionOptions
+        {
+            SheetIndices = new[] { 0, 2 }, // Alpha and Gamma only
+        };
+
+        var doc = ExcelToPdfConverter.Convert(excelStream, options);
+        var content = Encoding.ASCII.GetString(doc.ToArray());
+
+        Assert.Contains("AlphaCell", content);
+        Assert.DoesNotContain("BetaCell", content);
+        Assert.Contains("GammaCell", content);
+    }
+
+    [Fact]
+    public void Convert_WithSheetNames_OnlyRendersSpecifiedSheets()
+    {
+        using var excelStream = CreateMultiSheetExcel(
+            ("Sales",   new[] { new[] { "SalesData"   } }),
+            ("Costs",   new[] { new[] { "CostsData"   } }),
+            ("Summary", new[] { new[] { "SummaryData" } }));
+
+        var options = new ExcelToPdfConverter.ConversionOptions
+        {
+            SheetNames = new[] { "costs", "Summary" }, // case-insensitive
+        };
+
+        var doc = ExcelToPdfConverter.Convert(excelStream, options);
+        var content = Encoding.ASCII.GetString(doc.ToArray());
+
+        Assert.DoesNotContain("SalesData", content);
+        Assert.Contains("CostsData", content);
+        Assert.Contains("SummaryData", content);
+    }
+
+    [Fact]
+    public void Convert_SheetIndices_TakesPrecedenceOverSheetNames()
+    {
+        using var excelStream = CreateMultiSheetExcel(
+            ("First",  new[] { new[] { "FirstCell"  } }),
+            ("Second", new[] { new[] { "SecondCell" } }));
+
+        var options = new ExcelToPdfConverter.ConversionOptions
+        {
+            SheetIndices = new[] { 0 },          // First only
+            SheetNames   = new[] { "Second" },   // would select Second, but ignored
+        };
+
+        var doc = ExcelToPdfConverter.Convert(excelStream, options);
+        var content = Encoding.ASCII.GetString(doc.ToArray());
+
+        Assert.Contains("FirstCell", content);
+        Assert.DoesNotContain("SecondCell", content);
+    }
+
+    [Fact]
+    public void Convert_NoMatchingSheets_ProducesAtLeastOnePage()
+    {
+        using var excelStream = CreateMultiSheetExcel(
+            ("Sheet1", new[] { new[] { "Data" } }));
+
+        var options = new ExcelToPdfConverter.ConversionOptions
+        {
+            SheetNames = new[] { "DoesNotExist" },
+        };
+
+        var doc = ExcelToPdfConverter.Convert(excelStream, options);
+        Assert.True(doc.Pages.Count >= 1);
+    }
+
     /// <summary>
     /// Creates a minimal valid .xlsx file in memory with the given data.
     /// </summary>
@@ -405,4 +482,106 @@ int GetStringIndex(string value)
         ms.Position = 0;
         return ms;
     }
+
+    /// <summary>
+    /// Creates a minimal .xlsx with multiple named sheets, each containing string rows.
+    /// </summary>
+    private static MemoryStream CreateMultiSheetExcel(params (string name, string[][] rows)[] sheets)
+    {
+        var ms = new MemoryStream();
+
+        using (var archive = new ZipArchive(ms, ZipArchiveMode.Create, leaveOpen: true))
+        {
+            // [Content_Types].xml
+            var ctSb = new StringBuilder();
+            ctSb.AppendLine("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>");
+            ctSb.AppendLine("<Types xmlns=\"http://schemas.openxmlformats.org/package/2006/content-types\">");
+            ctSb.AppendLine("  <Default Extension=\"xml\" ContentType=\"application/xml\"/>");
+            ctSb.AppendLine("  <Default Extension=\"rels\" ContentType=\"application/vnd.openxmlformats-package.relationships+xml\"/>");
+            ctSb.AppendLine("  <Override PartName=\"/xl/workbook.xml\" ContentType=\"application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.main+xml\"/>");
+            for (var i = 0; i < sheets.Length; i++)
+                ctSb.AppendLine($"  <Override PartName=\"/xl/worksheets/sheet{i + 1}.xml\" ContentType=\"application/vnd.openxmlformats-officedocument.spreadsheetml.worksheet+xml\"/>");
+            ctSb.AppendLine("  <Override PartName=\"/xl/sharedStrings.xml\" ContentType=\"application/vnd.openxmlformats-officedocument.spreadsheetml.sharedStrings+xml\"/>");
+            ctSb.AppendLine("</Types>");
+            AddEntry(archive, "[Content_Types].xml", ctSb.ToString());
+
+            AddEntry(archive, "_rels/.rels",
+                """
+                <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+                <Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
+                  <Relationship Id="rId1" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument" Target="xl/workbook.xml"/>
+                </Relationships>
+                """);
+
+            // xl/_rels/workbook.xml.rels
+            var relsSb = new StringBuilder();
+            relsSb.AppendLine("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>");
+            relsSb.AppendLine("<Relationships xmlns=\"http://schemas.openxmlformats.org/package/2006/relationships\">");
+            for (var i = 0; i < sheets.Length; i++)
+                relsSb.AppendLine($"  <Relationship Id=\"rId{i + 1}\" Type=\"http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet\" Target=\"worksheets/sheet{i + 1}.xml\"/>");
+            relsSb.AppendLine($"  <Relationship Id=\"rId{sheets.Length + 1}\" Type=\"http://schemas.openxmlformats.org/officeDocument/2006/relationships/sharedStrings\" Target=\"sharedStrings.xml\"/>");
+            relsSb.AppendLine("</Relationships>");
+            AddEntry(archive, "xl/_rels/workbook.xml.rels", relsSb.ToString());
+
+            // xl/workbook.xml
+            var wbSb = new StringBuilder();
+            wbSb.AppendLine("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>");
+            wbSb.AppendLine("<workbook xmlns=\"http://schemas.openxmlformats.org/spreadsheetml/2006/main\" xmlns:r=\"http://schemas.openxmlformats.org/officeDocument/2006/relationships\">");
+            wbSb.AppendLine("  <sheets>");
+            for (var i = 0; i < sheets.Length; i++)
+                wbSb.AppendLine($"    <sheet name=\"{EscapeXml(sheets[i].name)}\" sheetId=\"{i + 1}\" r:id=\"rId{i + 1}\"/>");
+            wbSb.AppendLine("  </sheets>");
+            wbSb.AppendLine("</workbook>");
+            AddEntry(archive, "xl/workbook.xml", wbSb.ToString());
+
+            // Shared strings (global across all sheets)
+            var sharedStrings = new List<string>();
+            var sharedStringIndex = new Dictionary<string, int>();
+
+            int GetStringIndex(string value)
+            {
+                if (!sharedStringIndex.TryGetValue(value, out var idx))
+                {
+                    idx = sharedStrings.Count;
+                    sharedStrings.Add(value);
+                    sharedStringIndex[value] = idx;
+                }
+                return idx;
+            }
+
+            for (var i = 0; i < sheets.Length; i++)
+            {
+                var (_, rows) = sheets[i];
+                var sheetSb = new StringBuilder();
+                sheetSb.AppendLine("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>");
+                sheetSb.AppendLine("<worksheet xmlns=\"http://schemas.openxmlformats.org/spreadsheetml/2006/main\">");
+                sheetSb.AppendLine("<sheetData>");
+                for (var r = 0; r < rows.Length; r++)
+                {
+                    sheetSb.AppendLine($"  <row r=\"{r + 1}\">");
+                    for (var c = 0; c < rows[r].Length; c++)
+                    {
+                        var colLetter = (char)('A' + c);
+                        var idx = GetStringIndex(rows[r][c]);
+                        sheetSb.AppendLine($"    <c r=\"{colLetter}{r + 1}\" t=\"s\"><v>{idx}</v></c>");
+                    }
+                    sheetSb.AppendLine("  </row>");
+                }
+                sheetSb.AppendLine("</sheetData>");
+                sheetSb.AppendLine("</worksheet>");
+                AddEntry(archive, $"xl/worksheets/sheet{i + 1}.xml", sheetSb.ToString());
+            }
+
+            var ssSb = new StringBuilder();
+            ssSb.AppendLine("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>");
+            ssSb.AppendLine($"<sst xmlns=\"http://schemas.openxmlformats.org/spreadsheetml/2006/main\" count=\"{sharedStrings.Count}\" uniqueCount=\"{sharedStrings.Count}\">");
+            foreach (var s in sharedStrings)
+                ssSb.AppendLine($"  <si><t>{EscapeXml(s)}</t></si>");
+            ssSb.AppendLine("</sst>");
+            AddEntry(archive, "xl/sharedStrings.xml", ssSb.ToString());
+        }
+
+        ms.Position = 0;
+        return ms;
+    }
 }