Resolve #348, support delete Data Validation

3 files changed, 46 insertions, 5 deletions

diff --git a/datavalidation.go b/datavalidation.go
index 8b95b40..1aeb1dc 100644
--- a/datavalidation.go
+++ b/datavalidation.go
@@ -228,14 +228,38 @@ func convDataValidationOperatior(o DataValidationOperator) string {
 //     err = f.AddDataValidation("Sheet1", dvRange)
 //
 func (f *File) AddDataValidation(sheet string, dv *DataValidation) error {
-	xlsx, err := f.workSheetReader(sheet)
+	ws, err := f.workSheetReader(sheet)
 	if err != nil {
 		return err
 	}
-	if nil == xlsx.DataValidations {
-		xlsx.DataValidations = new(xlsxDataValidations)
+	if nil == ws.DataValidations {
+		ws.DataValidations = new(xlsxDataValidations)
 	}
-	xlsx.DataValidations.DataValidation = append(xlsx.DataValidations.DataValidation, dv)
-	xlsx.DataValidations.Count = len(xlsx.DataValidations.DataValidation)
+	ws.DataValidations.DataValidation = append(ws.DataValidations.DataValidation, dv)
+	ws.DataValidations.Count = len(ws.DataValidations.DataValidation)
 	return err
 }
+
+// DeleteDataValidation delete data validation by given worksheet name and
+// reference sequence.
+func (f *File) DeleteDataValidation(sheet, sqref string) error {
+	ws, err := f.workSheetReader(sheet)
+	if err != nil {
+		return err
+	}
+	if ws.DataValidations == nil {
+		return nil
+	}
+	dv := ws.DataValidations
+	for i := 0; i < len(dv.DataValidation); i++ {
+		if dv.DataValidation[i].Sqref == sqref {
+			dv.DataValidation = append(dv.DataValidation[:i], dv.DataValidation[i+1:]...)
+			i--
+		}
+	}
+	dv.Count = len(dv.DataValidation)
+	if dv.Count == 0 {
+		ws.DataValidations = nil
+	}
+	return nil
+}
diff --git a/datavalidation_test.go b/datavalidation_test.go
index c245df3..d70b874 100644
--- a/datavalidation_test.go
+++ b/datavalidation_test.go
@@ -85,3 +85,20 @@ func TestDataValidationError(t *testing.T) {
 	f = NewFile()
 	assert.EqualError(t, f.AddDataValidation("SheetN", nil), "sheet SheetN is not exist")
 }
+
+func TestDeleteDataValidation(t *testing.T) {
+	f := NewFile()
+	assert.NoError(t, f.DeleteDataValidation("Sheet1", "A1:B2"))
+
+	dvRange := NewDataValidation(true)
+	dvRange.Sqref = "A1:B2"
+	assert.NoError(t, dvRange.SetRange(10, 20, DataValidationTypeWhole, DataValidationOperatorBetween))
+	dvRange.SetInput("input title", "input body")
+	assert.NoError(t, f.AddDataValidation("Sheet1", dvRange))
+
+	assert.NoError(t, f.DeleteDataValidation("Sheet1", "A1:B2"))
+	assert.NoError(t, f.SaveAs(filepath.Join("test", "TestDeleteDataValidation.xlsx")))
+
+	// Test delete data validation on no exists worksheet.
+	assert.EqualError(t, f.DeleteDataValidation("SheetN", "A1:B2"), "sheet SheetN is not exist")
+}
diff --git a/test/images/chart.png b/test/images/chart.png
index 9fcd28a..dc30051 100644
--- a/test/images/chart.png
+++ b/test/images/chart.png