Allow deleting rows in xls files after expanding template (#363)

* Allow deleting rows in xls files after expanding template

* Update user guide and release notes

Author: ohecker

core/src/main/java/com/devonfw/tools/solicitor/writer/xls/ExcelWriter.java

@@ -414,6 +414,8 @@ public void writeReport(WriterConfig config, String target, Map<String, DataTabl
         iterateFromCell(wb, cell, dataTable, label, styleCache);
       }
 
+      findAndRemoveRowsToBeDeleted(wb);
+
       // force reevaluation of all formulas
       wb.setForceFormulaRecalculation(true);
 
@@ -431,6 +433,81 @@ public void writeReport(WriterConfig config, String target, Map<String, DataTabl
 
   }
 
+  /**
+   * Find any rows with cells that contain "_row_to_be_deleted_" and remove them from the workbook. This can be used to
+   * insert rows into sheets which might act as anchors to range evaluations and delete them at the end of template
+   * expansion.
+   *
+   * @param wb the workbook to process
+   */
+  private void findAndRemoveRowsToBeDeleted(Workbook wb) {
+
+    outer: while (true) {
+      for (Sheet sheet : wb) {
+        for (Row row : sheet) {
+          for (Cell cell : row) {
+            if (cell.getCellType() == CellType.STRING && "_row_to_be_deleted_".equals(cell.getStringCellValue())) {
+              LOG.debug("Removing row " + row.getRowNum() + " in sheet '" + sheet.getSheetName()
+                  + "' which was marked for deletion.");
+              removeRowOfCell(cell);
+              continue outer;
+            }
+          }
+        }
+      }
+      break;
+    }
+  }
+
+  /**
+   * Removes the row of the given cell from the workbook.
+   *
+   * @param cell the cell whose row should be removed
+   */
+  private static void removeRowOfCell(Cell cell) {
+
+    Sheet sheet = cell.getSheet();
+    int lastRowNum = cell.getSheet().getLastRowNum();
+    Row row = cell.getRow();
+    int rowIndex = row.getRowNum();
+
+    // 1) Remove merged regions that intersect the row
+    removeMergedRegionsInRow(sheet, rowIndex);
+
+    // 2) Remove row cells (optional but safer to avoid leftovers)
+    if (row != null) {
+      for (int cn = row.getFirstCellNum(); cn < row.getLastCellNum(); cn++) {
+        Cell cellToBeRemoved = row.getCell(cn);
+        if (cellToBeRemoved != null)
+          row.removeCell(cellToBeRemoved);
+      }
+    }
+    if (row != null)
+      sheet.removeRow(row);
+
+    // 3) Shift rows up if not deleting the last row
+    if (rowIndex < lastRowNum) {
+      sheet.shiftRows(rowIndex + 1, lastRowNum, -1, true, false);
+    }
+  }
+
+  /**
+   * Removes all merged regions in the given sheet that intersect the given row index. This is necessary to avoid
+   * exceptions when shifting rows up after removing a row that is part of a merged region.
+   *
+   * @param sheet the sheet to process
+   * @param rowIndex the index of the row for which intersecting merged regions should be removed
+   */
+  private static void removeMergedRegionsInRow(Sheet sheet, int rowIndex) {
+
+    for (int i = sheet.getNumMergedRegions() - 1; i >= 0; i--) {
+      CellRangeAddress region = sheet.getMergedRegion(i);
+      if (region.getFirstRow() <= rowIndex && region.getLastRow() >= rowIndex) {
+        sheet.removeMergedRegion(i);
+      }
+    }
+  }
+
   /**
    * Protects/locks all sheets in the workbook if the value given by {@link WriterConfig#getProtectionPassword()} is not
    * <code>null</code> or empty. If the configured value is literal "RANDOM", a random password will be generated and

documentation/master-solicitor.asciidoc

@@ -1311,6 +1311,8 @@ Within each row which was copied in the previous step the templating logic searc
 NOTE: Performance hint: Using Hyperlinks in "template rows" might result in degraded performance when Solicitor processes the XLS template. This is
 due to the fact that copying cells that are marked to be hyperlinks might be slow if the XLS file contains a lot of hyperlinks. This performance issue might be avoided if hyperlinks are represented as formulas like `=HYPERLINK("https://www.google.com")` or `=HYPERLINK("$someUrlPlaceholder$")` instead of defining a hyperlink via the "Link" context menu entry of Excel.
 
+===== Optional deletion of rows after template expansion
+After the template has been expanded the ExcelWriter will look for any cells in the Excel-Sheet which contain the text `\_row_to_be_deleted_`. All rows containing such cells will be deleted.
 
 ===== Representation of Diff Information
 In case that a difference processing (new vs. old model data) was done this will be represented
@@ -2098,6 +2100,7 @@ creating a rule template file, defining the decision table as XLS or CSV file an
 == Release Notes
 Changes in 1.49.0::
 * https://github.com/devonfw/solicitor/issues/360: Allow alignment of groupId, artifactId and version to PackageURL when reading component lists with Readers. See <<Deriving groupId, ArtifactId and Version from the PackageURL>>.
+* https://github.com/devonfw/solicitor/pull/363: Allow to delete rows in XLS files generated by the ExcelWriter. See <<Optional deletion of rows after template expansion>>.
 
 Changes in 1.48.0::
 * https://github.com/devonfw/solicitor/pull/357: Refactor model import logic.