Merge pull request #267 from rentiansheng/valiationdata, this closes #147 and closes #240.

 Initialize data validation support

3 files changed, 260 insertions, 6 deletions

diff --git a/datavalidation.go b/datavalidation.go
new file mode 100644
index 0000000..62d2cf8
--- /dev/null
+++ b/datavalidation.go
@@ -0,0 +1,203 @@
+package excelize
+
+import (
+	"fmt"
+	"strings"
+)
+
+// DataValidationType defined the type of data validation.
+type DataValidationType int
+
+// Data validation types.
+const (
+	_DataValidationType = iota
+	typeNone            // inline use
+	DataValidationTypeCustom
+	DataValidationTypeDate
+	DataValidationTypeDecimal
+	typeList // inline use
+	DataValidationTypeTextLeng
+	DataValidationTypeTime
+	// DataValidationTypeWhole Integer
+	DataValidationTypeWhole
+)
+
+const (
+	// dataValidationFormulaStrLen 255 characters+ 2 quotes
+	dataValidationFormulaStrLen = 257
+	// dataValidationFormulaStrLenErr
+	dataValidationFormulaStrLenErr = "data validation must be 0-255 characters"
+)
+
+// DataValidationErrorStyle defined the style of data validation error alert.
+type DataValidationErrorStyle int
+
+// Data validation error styles.
+const (
+	_ DataValidationErrorStyle = iota
+	DataValidationErrorStyleStop
+	DataValidationErrorStyleWarning
+	DataValidationErrorStyleInformation
+)
+
+// Data validation error styles.
+const (
+	styleStop        = "stop"
+	styleWarning     = "warning"
+	styleInformation = "information"
+)
+
+// DataValidationOperator operator enum.
+type DataValidationOperator int
+
+// Data validation operators.
+const (
+	_DataValidationOperator = iota
+	DataValidationOperatorBetween
+	DataValidationOperatorEqual
+	DataValidationOperatorGreaterThan
+	DataValidationOperatorGreaterThanOrEqual
+	DataValidationOperatorLessThan
+	DataValidationOperatorLessThanOrEqual
+	DataValidationOperatorNotBetween
+	DataValidationOperatorNotEqual
+)
+
+// NewDataValidation return data validation struct.
+func NewDataValidation(allowBlank bool) *DataValidation {
+	return &DataValidation{
+		AllowBlank:       allowBlank,
+		ShowErrorMessage: false,
+		ShowInputMessage: false,
+	}
+}
+
+// SetError set error notice.
+func (dd *DataValidation) SetError(style DataValidationErrorStyle, title, msg string) {
+	dd.Error = &msg
+	dd.ErrorTitle = &title
+	strStyle := styleStop
+	switch style {
+	case DataValidationErrorStyleStop:
+		strStyle = styleStop
+	case DataValidationErrorStyleWarning:
+		strStyle = styleWarning
+	case DataValidationErrorStyleInformation:
+		strStyle = styleInformation
+
+	}
+	dd.ShowErrorMessage = true
+	dd.ErrorStyle = &strStyle
+}
+
+// SetInput set prompt notice.
+func (dd *DataValidation) SetInput(title, msg string) {
+	dd.ShowInputMessage = true
+	dd.PromptTitle = &title
+	dd.Prompt = &msg
+}
+
+// SetDropList data validation list.
+func (dd *DataValidation) SetDropList(keys []string) error {
+	dd.Formula1 = "\"" + strings.Join(keys, ",") + "\""
+	dd.Type = convDataValidationType(typeList)
+	return nil
+}
+
+// SetRange provides function to set data validation range in drop list.
+func (dd *DataValidation) SetRange(f1, f2 int, t DataValidationType, o DataValidationOperator) error {
+	formula1 := fmt.Sprintf("%d", f1)
+	formula2 := fmt.Sprintf("%d", f2)
+	if dataValidationFormulaStrLen < len(dd.Formula1) || dataValidationFormulaStrLen < len(dd.Formula2) {
+		return fmt.Errorf(dataValidationFormulaStrLenErr)
+	}
+
+	dd.Formula1 = formula1
+	dd.Formula2 = formula2
+	dd.Type = convDataValidationType(t)
+	dd.Operator = convDataValidationOperatior(o)
+	return nil
+}
+
+// SetSqref provides function to set data validation range in drop list.
+func (dd *DataValidation) SetSqref(sqref string) {
+	if dd.Sqref == "" {
+		dd.Sqref = sqref
+	} else {
+		dd.Sqref = fmt.Sprintf("%s %s", dd.Sqref, sqref)
+	}
+}
+
+// convDataValidationType get excel data validation type.
+func convDataValidationType(t DataValidationType) string {
+	typeMap := map[DataValidationType]string{
+		typeNone:                   "none",
+		DataValidationTypeCustom:   "custom",
+		DataValidationTypeDate:     "date",
+		DataValidationTypeDecimal:  "decimal",
+		typeList:                   "list",
+		DataValidationTypeTextLeng: "textLength",
+		DataValidationTypeTime:     "time",
+		DataValidationTypeWhole:    "whole",
+	}
+
+	return typeMap[t]
+
+}
+
+// convDataValidationOperatior get excel data validation operator.
+func convDataValidationOperatior(o DataValidationOperator) string {
+	typeMap := map[DataValidationOperator]string{
+		DataValidationOperatorBetween:            "between",
+		DataValidationOperatorEqual:              "equal",
+		DataValidationOperatorGreaterThan:        "greaterThan",
+		DataValidationOperatorGreaterThanOrEqual: "greaterThanOrEqual",
+		DataValidationOperatorLessThan:           "lessThan",
+		DataValidationOperatorLessThanOrEqual:    "lessThanOrEqual",
+		DataValidationOperatorNotBetween:         "notBetween",
+		DataValidationOperatorNotEqual:           "notEqual",
+	}
+
+	return typeMap[o]
+
+}
+
+// AddDataValidation provides set data validation on a range of the worksheet
+// by given data validation object and worksheet name. The data validation
+// object can be created by NewDataValidation function.
+//
+// Example 1, set data validation on Sheet1!A1:B2 with validation criteria
+// settings, show error alert after invalid data is entered whth "Stop" style
+// and custom title "error body":
+//
+//     dvRange := excelize.NewDataValidation(true)
+// 	   dvRange.Sqref = "A1:B2"
+//     dvRange.SetRange(10, 20, excelize.DataValidationTypeWhole, excelize.DataValidationOperatorBetween)
+//     dvRange.SetError(excelize.DataValidationErrorStyleStop, "error title", "error body")
+//     xlsx.AddDataValidation("Sheet1", dvRange)
+//
+// Example 2, set data validation on Sheet1!A3:B4 with validation criteria
+// settings, and show input message when cell is selected:
+//
+//     dvRange = excelize.NewDataValidation(true)
+//     dvRange.Sqref = "A3:B4"
+//     dvRange.SetRange(10, 20, excelize.DataValidationTypeWhole, excelize.DataValidationOperatorGreaterThan)
+//     dvRange.SetInput("input title", "input body")
+//     xlsx.AddDataValidation("Sheet1", dvRange)
+//
+// Example 4, set data validation on Sheet1!A5:B6 with validation criteria
+// settings, create in-cell dropdown by allow list source:
+//
+//     dvRange = excelize.NewDataValidation(true)
+//     dvRange.Sqref = "A5:B6"
+//     dvRange.SetDropList([]string{"1", "2", "3"})
+//     xlsx.AddDataValidation("Sheet1", dvRange)
+//
+func (f *File) AddDataValidation(sheet string, dv *DataValidation) {
+	xlsx := f.workSheetReader(sheet)
+	if nil == xlsx.DataValidations {
+		xlsx.DataValidations = new(xlsxDataValidations)
+	}
+	xlsx.DataValidations.DataValidation = append(xlsx.DataValidations.DataValidation, dv)
+	xlsx.DataValidations.Count = len(xlsx.DataValidations.DataValidation)
+}
diff --git a/datavalidation_test.go b/datavalidation_test.go
new file mode 100644
index 0000000..718131f
--- /dev/null
+++ b/datavalidation_test.go
@@ -0,0 +1,32 @@
+package excelize
+
+import (
+	"testing"
+)
+
+func TestDataValidation(t *testing.T) {
+	xlsx := NewFile()
+
+	dvRange := NewDataValidation(true)
+	dvRange.Sqref = "A1:B2"
+	dvRange.SetRange(10, 20, DataValidationTypeWhole, DataValidationOperatorBetween)
+	dvRange.SetError(DataValidationErrorStyleStop, "error title", "error body")
+	xlsx.AddDataValidation("Sheet1", dvRange)
+
+	dvRange = NewDataValidation(true)
+	dvRange.Sqref = "A3:B4"
+	dvRange.SetRange(10, 20, DataValidationTypeWhole, DataValidationOperatorGreaterThan)
+	dvRange.SetInput("input title", "input body")
+	xlsx.AddDataValidation("Sheet1", dvRange)
+
+	dvRange = NewDataValidation(true)
+	dvRange.Sqref = "A5:B6"
+	dvRange.SetDropList([]string{"1", "2", "3"})
+	xlsx.AddDataValidation("Sheet1", dvRange)
+
+	// Test write file to given path.
+	err := xlsx.SaveAs("./test/Bookdatavalition.xlsx")
+	if err != nil {
+		t.Error(err)
+	}
+}
diff --git a/xmlWorksheet.go b/xmlWorksheet.go
index 87d66a1..7cf4994 100644
--- a/xmlWorksheet.go
+++ b/xmlWorksheet.go
@@ -18,7 +18,7 @@ type xlsxWorksheet struct {
 	MergeCells            *xlsxMergeCells              `xml:"mergeCells"`
 	PhoneticPr            *xlsxPhoneticPr              `xml:"phoneticPr"`
 	ConditionalFormatting []*xlsxConditionalFormatting `xml:"conditionalFormatting"`
-	DataValidations       *xlsxDataValidations         `xml:"dataValidations"`
+	DataValidations       *xlsxDataValidations         `xml:"dataValidations,omitempty"`
 	Hyperlinks            *xlsxHyperlinks              `xml:"hyperlinks"`
 	PrintOptions          *xlsxPrintOptions            `xml:"printOptions"`
 	PageMargins           *xlsxPageMargins             `xml:"pageMargins"`
@@ -294,11 +294,30 @@ type xlsxMergeCells struct {
 // xlsxDataValidations expresses all data validation information for cells in a
 // sheet which have data validation features applied.
 type xlsxDataValidations struct {
-	Count          int    `xml:"count,attr,omitempty"`
-	DisablePrompts bool   `xml:"disablePrompts,attr,omitempty"`
-	XWindow        int    `xml:"xWindow,attr,omitempty"`
-	YWindow        int    `xml:"yWindow,attr,omitempty"`
-	DataValidation string `xml:",innerxml"`
+	Count          int               `xml:"count,attr,omitempty"`
+	DisablePrompts bool              `xml:"disablePrompts,attr,omitempty"`
+	XWindow        int               `xml:"xWindow,attr,omitempty"`
+	YWindow        int               `xml:"yWindow,attr,omitempty"`
+	DataValidation []*DataValidation `xml:"dataValidation"`
+}
+
+// DataValidation directly maps the a single item of data validation defined
+// on a range of the worksheet.
+type DataValidation struct {
+	AllowBlank       bool    `xml:"allowBlank,attr"`
+	Error            *string `xml:"error,attr"`
+	ErrorStyle       *string `xml:"errorStyle,attr"`
+	ErrorTitle       *string `xml:"errorTitle,attr"`
+	Operator         string  `xml:"operator,attr"`
+	Prompt           *string `xml:"prompt,attr"`
+	PromptTitle      *string `xml:"promptTitle"`
+	ShowDropDown     bool    `xml:"showDropDown,attr"`
+	ShowErrorMessage bool    `xml:"showErrorMessage,attr"`
+	ShowInputMessage bool    `xml:"showInputMessage,attr"`
+	Sqref            string  `xml:"sqref,attr"`
+	Type             string  `xml:"type,attr"`
+	Formula1         string  `xml:"formula1"`
+	Formula2         string  `xml:"formula2"`
 }
 
 // xlsxC directly maps the c element in the namespace