spreadsheet: support adding/removing an auto filter

_examples/spreadsheet/sort-filter/main.go

@@ -0,0 +1,35 @@
+// Copyright 2017 Baliance. All rights reserved.
+package main
+
+import (
+	"fmt"
+	"log"
+
+	"baliance.com/gooxml/spreadsheet"
+)
+
+func main() {
+	ss := spreadsheet.New()
+	// add a single sheet
+	sheet := ss.AddSheet()
+	hdrRow := sheet.AddRow()
+	hdrRow.AddCell().SetString("Product Name")
+	hdrRow.AddCell().SetString("Quantity")
+	hdrRow.AddCell().SetString("Price")
+	sheet.SetAutoFilter("A1:C6")
+
+	// rows
+	for r := 0; r < 5; r++ {
+		row := sheet.AddRow()
+		row.AddCell().SetString(fmt.Sprintf("Product %d", r+1))
+		row.AddCell().SetNumber(float64(r + 2))
+		row.AddCell().SetNumber(float64(3*r + 1))
+
+	}
+
+	if err := ss.Validate(); err != nil {
+		log.Fatalf("error validating sheet: %s", err)
+	}
+
+	ss.SaveToFile("sort-filter.xlsx")
+}

spreadsheet/definedname.go

@@ -8,6 +8,7 @@
 package spreadsheet
 
 import sml "baliance.com/gooxml/schema/schemas.openxmlformats.org/spreadsheetml"
+import "baliance.com/gooxml"
 
 // DefinedName is a named range, formula, etc.
 type DefinedName struct {
@@ -28,3 +29,18 @@ func (d DefinedName) Name() string {
 func (d DefinedName) Content() string {
 	return d.x.Content
 }
+
+// SetContent sets the defined name content.
+func (d DefinedName) SetContent(s string) {
+	d.x.Content = s
+}
+
+// SetHidden marks the defined name as hidden.
+func (d DefinedName) SetHidden(b bool) {
+	d.x.HiddenAttr = gooxml.Bool(b)
+}
+
+// SetHidden marks the defined name as hidden.
+func (d DefinedName) SetLocalSheetID(id uint32) {
+	d.x.LocalSheetIdAttr = gooxml.Uint32(id)
+}

spreadsheet/sheet.go

@@ -25,6 +25,11 @@ type Sheet struct {
 	x   *sml.Worksheet
 }
 
+// X returns the inner wrapped XML type.
+func (s Sheet) X() *sml.Worksheet {
+	return s.x
+}
+
 // Row will return a row with a given row number, creating a new row if
 // necessary.
 func (s Sheet) Row(rowNum uint32) Row {
@@ -193,3 +198,56 @@ func (s Sheet) RangeReference(n string) string {
 	to := fmt.Sprintf("$%s$%d", tc, tr)
 	return fmt.Sprintf(`'%s'!%s:%s`, s.Name(), from, to)
 }
+
+const autoFilterName = "_xlnm._FilterDatabase"
+
+// ClearAutoFilter removes the autofilters from the sheet.
+func (s Sheet) ClearAutoFilter() {
+	s.x.AutoFilter = nil
+	sn := "'" + s.Name() + "'!"
+	// see if we have a defined auto filter name for the sheet
+	for _, dn := range s.w.DefinedNames() {
+		if dn.Name() == autoFilterName {
+			if strings.HasPrefix(dn.Content(), sn) {
+				s.w.RemoveDefinedName(dn)
+				break
+			}
+		}
+	}
+}
+
+// SetAutoFilter creates autofilters on the sheet. These are the automatic
+// filters that are common for a header row.  The RangeRef should be of the form
+// "A1:C5" and cover the entire range of cells to be filtered, not just the
+// header. SetAutoFilter replaces any existing auto filter on the sheet.
+func (s Sheet) SetAutoFilter(rangeRef string) {
+	// this should have no $ in it
+	rangeRef = strings.Replace(rangeRef, "$", "", -1)
+
+	s.x.AutoFilter = sml.NewCT_AutoFilter()
+	s.x.AutoFilter.RefAttr = gooxml.String(rangeRef)
+	sn := "'" + s.Name() + "'!"
+	var sdn DefinedName
+
+	// see if we already have a defined auto filter name for the sheet
+	for _, dn := range s.w.DefinedNames() {
+		if dn.Name() == autoFilterName {
+			if strings.HasPrefix(dn.Content(), sn) {
+				sdn = dn
+				// name must match, but make sure rangeRef matches as well
+				sdn.SetContent(s.RangeReference(rangeRef))
+				break
+			}
+		}
+	}
+	// no existing name found, so add a new one
+	if sdn.X() == nil {
+		sdn = s.w.AddDefinedName(autoFilterName, s.RangeReference(rangeRef))
+	}
+
+	for i, ws := range s.w.xws {
+		if ws == s.x {
+			sdn.SetLocalSheetID(uint32(i))
+		}
+	}
+}

spreadsheet/sheet_test.go

@@ -82,3 +82,42 @@ func TestRowNumberValidation(t *testing.T) {
 		t.Errorf("expected validation error with identically numbered rows")
 	}
 }
+
+func TestAutoFilter(t *testing.T) {
+	wb := spreadsheet.New()
+	sheet := wb.AddSheet()
+	if len(wb.DefinedNames()) != 0 {
+		t.Errorf("expected no defined names for new workbook")
+	}
+	sheet.SetAutoFilter("A1:C10")
+	if len(wb.DefinedNames()) != 1 {
+		t.Errorf("expected a new defined names for the autofilter")
+	}
+	dn := wb.DefinedNames()[0]
+	expContent := "'Sheet 1'!$A$1:$C$10"
+	if dn.Content() != expContent {
+		t.Errorf("expected defined name content = '%s', got %s", expContent, dn.Content())
+	}
+
+	sheet.SetAutoFilter("A1:B10")
+	expContent = "'Sheet 1'!$A$1:$B$10"
+	// setting the filter again should re-write the defined name and not create a new one
+	if len(wb.DefinedNames()) != 1 {
+		t.Errorf("expected a new defined names for the autofilter")
+	}
+	dn = wb.DefinedNames()[0]
+	// but the content should have changed
+	if dn.Content() != expContent {
+		t.Errorf("expected defined name content = '%s', got %s", expContent, dn.Content())
+	}
+
+	sheet.ClearAutoFilter()
+	if len(wb.DefinedNames()) != 0 {
+		t.Errorf("clearing the filter should have removed the defined name")
+	}
+
+	if sheet.X().AutoFilter != nil {
+		t.Errorf("autofilter should have been nil after clear")
+	}
+
+}

spreadsheet/workbook.go

@@ -351,6 +351,22 @@ func (wb *Workbook) AddDefinedName(name, ref string) DefinedName {
 	return DefinedName{dn}
 }
 
+// RemoveDefinedName removes an existing defined name.
+func (wb *Workbook) RemoveDefinedName(dn DefinedName) error {
+	if dn.X() == nil {
+		return errors.New("attempt to remove nil DefinedName")
+	}
+	for i, sdn := range wb.x.DefinedNames.DefinedName {
+		if sdn == dn.X() {
+			copy(wb.x.DefinedNames.DefinedName[i:], wb.x.DefinedNames.DefinedName[i+1:])
+			wb.x.DefinedNames.DefinedName[len(wb.x.DefinedNames.DefinedName)-1] = nil
+			wb.x.DefinedNames.DefinedName = wb.x.DefinedNames.DefinedName[:len(wb.x.DefinedNames.DefinedName)-1]
+			return nil
+		}
+	}
+	return errors.New("defined name not found")
+}
+
 // DefinedNames returns a slice of all defined names in the workbook.
 func (wb *Workbook) DefinedNames() []DefinedName {
 	if wb.x.DefinedNames == nil {