feat: support locale option for formattedValue & set locale numFmtMap

cell.go

@@ -1350,20 +1350,44 @@ func (f *File) formattedValue(c *xlsxC, raw bool, cellType CellType) (string, er
 	if wb != nil && wb.WorkbookPr != nil {
 		date1904 = wb.WorkbookPr.Date1904
 	}
-	if ok := builtInNumFmtFunc[numFmtID]; ok != nil {
-		return ok(c.V, builtInNumFmt[numFmtID], date1904, cellType), err
+	if styleSheet.NumFmts != nil {
+		for _, xlsxFmt := range styleSheet.NumFmts.NumFmt {
+			if xlsxFmt.NumFmtID == numFmtID {
+				return format(c.V, xlsxFmt.FormatCode, date1904, cellType), err
+			}
+		}
 	}
-	if styleSheet.NumFmts == nil {
-		return c.V, err
+	numFmtFunc := builtInNumFmtFunc[numFmtID]
+	numFmtCode := f.getBuiltInNumFmtCode(numFmtID)
+	if numFmtFunc != nil {
+		return numFmtFunc(c.V, numFmtCode, date1904, cellType), err
 	}
-	for _, xlsxFmt := range styleSheet.NumFmts.NumFmt {
-		if xlsxFmt.NumFmtID == numFmtID {
-			return format(c.V, xlsxFmt.FormatCode, date1904, cellType), err
-		}
+	if numFmtCode != "" {
+		// default use format parse value
+		return format(c.V, numFmtCode, date1904, cellType), err
 	}
 	return c.V, err
 }
 
+func (f *File) getBuiltInNumFmtCode(numFmtId int) string {
+	locale := ""
+	if f.options != nil {
+		locale = f.options.Locale
+	}
+	numFmtCode := builtInNumFmt[numFmtId]
+	if locale == "" {
+		return numFmtCode
+	}
+	localeNumFmtMap, localeOk := langNumFmt[locale]
+	if localeOk {
+		localeNumFmtCode, ok := localeNumFmtMap[numFmtId]
+		if ok {
+			numFmtCode = localeNumFmtCode
+		}
+	}
+	return numFmtCode
+}
+
 // prepareCellStyle provides a function to prepare style index of cell in
 // worksheet by given column index and style index.
 func (f *File) prepareCellStyle(ws *xlsxWorksheet, col, row, style int) int {

cell_test.go

@@ -877,6 +877,46 @@ func TestFormattedValue(t *testing.T) {
 		assert.Equal(t, "0_0", fn("0_0", "", false, CellTypeNumber))
 	}
 
+	// Test format value with built-in number format ID = 14
+	styleID, err = f.NewStyle(&Style{
+		NumFmt: 14,
+	})
+	assert.NoError(t, err)
+	result, err = f.formattedValue(&xlsxC{S: styleID, V: "43528"}, false, CellTypeNumber)
+	assert.NoError(t, err)
+	assert.Equal(t, "03-04-19", result)
+	originalFileOptions := f.options
+	f.options = &Options{
+		Locale: "zh-cn",
+	}
+	result, err = f.formattedValue(&xlsxC{S: styleID, V: "43528"}, false, CellTypeNumber)
+	assert.NoError(t, err)
+	assert.Equal(t, "2019/3/4", result)
+	f.options = originalFileOptions
+
+	// Test format value with built-in number format zh-cn
+	styleID31, err := f.NewStyle(&Style{
+		NumFmt: 31,
+		Lang:   "zh-cn",
+	})
+	assert.NoError(t, err)
+	styleID57, err := f.NewStyle(&Style{
+		NumFmt: 57,
+		Lang:   "zh-cn",
+	})
+	assert.NoError(t, err)
+	originalFileOptions = f.options
+	f.options = &Options{
+		Locale: "zh-cn",
+	}
+	result, err = f.formattedValue(&xlsxC{S: styleID31, V: "43528"}, false, CellTypeNumber)
+	assert.NoError(t, err)
+	assert.Equal(t, "2019年3月4日", result)
+	result, err = f.formattedValue(&xlsxC{S: styleID57, V: "43528"}, false, CellTypeNumber)
+	assert.NoError(t, err)
+	assert.Equal(t, "2019年3月", result)
+	f.options = originalFileOptions
+
 	// Test format value with unsupported charset workbook
 	f.WorkBook = nil
 	f.Pkg.Store(defaultXMLPathWorkbook, MacintoshCyrillicCharset)

excelize.go

@@ -79,12 +79,16 @@ type charsetTranscoderFn func(charset string, input io.Reader) (rdr io.Reader, e
 // temporary directory when the file size is over this value, this value
 // should be less than or equal to UnzipSizeLimit, the default value is
 // 16MB.
+//
+// Locale specifies the file parse locale, The resolution of the locale
+// in the file will be affected;
 type Options struct {
 	MaxCalcIterations uint
 	Password          string
 	RawCellValue      bool
 	UnzipSizeLimit    int64
 	UnzipXMLSizeLimit int64
+	Locale            string
 }
 
 // OpenFile take the name of an spreadsheet file and returns a populated

styles.go

@@ -86,6 +86,7 @@ var langNumFmt = map[string]map[int]string{
 		58: `[$-404]e"年"m"月"d"日"`,
 	},
 	"zh-cn": {
+		14: `yyyy/m/d`,
 		27: `yyyy"年"m"月"`,
 		28: `m"月"d"日"`,
 		29: `m"月"d"日"`,