Open Source Go Library for Creating Excel XLSX Files

Getting Started with unioffice

The recommended way to unioffice into your project is by using Github. Please use the following command for a smooth installation.

go get github.com/unidoc/unioffice/
go build -i github.com/unidoc/unioffice/... 

Excel XLSX Creation via Go API

The Open source library unioffice allows computer programmers to create an Excel XLSX spreadsheet inside their own Go applications. It gives you the capability to add a new sheet to your existing Excel documents and assign a name to a sheet and save the file to the path of your choice. It also provides support for several important features such as adding new rows and columns to a sheet, defining the number of rows and columns, setting the default value of a cell, and more. You can also open and modify the existing spreadsheet with ease.

func main() {
	ss := spreadsheet.New()
	defer ss.Close()
	// add a single sheet
	sheet := ss.AddSheet()

	// rows
	for r := 0; r < 5; r++ {
		row := sheet.AddRow()
		// and cells
		for c := 0; c < 5; c++ {
			cell := row.AddCell()
			cell.SetString(fmt.Sprintf("row %d cell %d", r, c))
		}
	}

	if err := ss.Validate(); err != nil {
		log.Fatalf("error validating sheet: %s", err)
	}

	ss.SaveToFile("simple.xlsx")
} 

Add Multiple Charts to an Excel XLSX File

The unioffice library has provided support for adding charts to an Excel spreadsheet with just a couple of lines of code. You can create charts based on the available data in your worksheet as well as without the availability of any data at all. Charts give you the capability to visually display data in different formats such as Bar, Column, Pie, Line, Area, or Radar, etc. Developers can easily select from the available chart options and can control their values.

func main() {
	ss := spreadsheet.New()
	defer ss.Close()
	sheet := ss.AddSheet()

	// Create all of our data
	row := sheet.AddRow()
	row.AddCell().SetString("Item")
	row.AddCell().SetString("Price")
	row.AddCell().SetString("# Sold")
	row.AddCell().SetString("Total")
	for r := 0; r < 5; r++ {
		row := sheet.AddRow()
		row.AddCell().SetString(fmt.Sprintf("Product %d", r+1))
		row.AddCell().SetNumber(1.23 * float64(r+1))
		row.AddCell().SetNumber(float64(r%3 + 1))
		row.AddCell().SetFormulaRaw(fmt.Sprintf("C%d*B%d", r+2, r+2))
	}

	// Charts need to reside in a drawing
	dwng := ss.AddDrawing()
	chrt1, anc1 := dwng.AddChart(spreadsheet.AnchorTypeTwoCell)
	chrt2, anc2 := dwng.AddChart(spreadsheet.AnchorTypeTwoCell)
	addBarChart(chrt1)
	addLineChart(chrt2)
	anc1.SetWidth(9)
	anc1.MoveTo(5, 1)
	anc2.MoveTo(1, 23)

	// and finally add the chart to the sheet
	sheet.SetDrawing(dwng)

	if err := ss.Validate(); err != nil {
		log.Fatalf("error validating sheet: %s", err)
	}
	ss.SaveToFile("multiple-chart.xlsx")
}

func addBarChart(chrt chart.Chart) {
	chrt.AddTitle().SetText("Bar Chart")
	lc := chrt.AddBarChart()
	priceSeries := lc.AddSeries()
	priceSeries.SetText("Price")
	// Set a category axis reference on the first series to pull the product names
	priceSeries.CategoryAxis().SetLabelReference(`'Sheet 1'!A2:A6`)
	priceSeries.Values().SetReference(`'Sheet 1'!B2:B6`)

	soldSeries := lc.AddSeries()
	soldSeries.SetText("Sold")
	soldSeries.Values().SetReference(`'Sheet 1'!C2:C6`)

	totalSeries := lc.AddSeries()
	totalSeries.SetText("Total")
	totalSeries.Values().SetReference(`'Sheet 1'!D2:D6`)

	// the line chart accepts up to two axes
	ca := chrt.AddCategoryAxis()
	va := chrt.AddValueAxis()
	lc.AddAxis(ca)
	lc.AddAxis(va)

	ca.SetCrosses(va)
	va.SetCrosses(ca)
}

Insert Images to XLSX Spreadsheets

The unioffice library fully supports the inclusion of images into XLSX Spreadsheets with just a couple of lines of Go code. It supports modifying images as well as deleting existing images inside an XLSX worksheet. It also provides options to insert a picture and set its properties like size, position, etc. as well as printing support.

func main() {
	ss := spreadsheet.New()
	defer ss.Close()
	// add a single sheet
	sheet := ss.AddSheet()

	img, err := common.ImageFromFile("gophercolor.png")
	if err != nil {
		log.Fatalf("unable to create image: %s", err)
	}

	iref, err := ss.AddImage(img)
	if err != nil {
		log.Fatalf("unable to add image to workbook: %s", err)
	}

	dwng := ss.AddDrawing()
	sheet.SetDrawing(dwng)
	for i := float64(0); i < 360; i += 30 {
		anc := dwng.AddImage(iref, spreadsheet.AnchorTypeAbsolute)

		ang := i * math.Pi / 180
		x := 2 + 2*math.Cos(ang)
		y := 2 + +2*math.Sin(ang)
		anc.SetColOffset(measurement.Distance(x) * measurement.Inch)
		anc.SetRowOffset(measurement.Distance(y) * measurement.Inch)

		// set the image to 1x1 inches
		var w measurement.Distance = 1 * measurement.Inch
		anc.SetWidth(w)
		anc.SetHeight(iref.RelativeHeight(w))
	}

	if err := ss.Validate(); err != nil {
		log.Fatalf("error validating sheet: %s", err)
	}

	ss.SaveToFile("image.xlsx")
}

Apply Conditional Formatting on Spreadsheet’s Cells

Conditional Formatting is a useful feature that helps Excel users to apply a format to a cell or a range of cells based on certain criteria. The unioffice library has provided functionality that enables software developers to apply conditional formatting to their spreadsheet with just a couple of Go commands. The library has included support for conditionally formatting cells, styling, gradients, icons, data bar & more to come.