go-chart/_examples/bar_chart/main.go
2016-08-06 21:59:46 -07:00

54 lines
1,021 B
Go

package main
import (
"fmt"
"log"
"net/http"
"os"
"github.com/wcharczuk/go-chart"
)
func drawChart(res http.ResponseWriter, req *http.Request) {
sbc := chart.BarChart{
Height: 512,
BarWidth: 60,
XAxis: chart.Style{
Show: true,
},
YAxis: chart.YAxis{
Style: chart.Style{
Show: true,
},
},
Bars: []chart.Value{
{Value: 5.25, Label: "Blue"},
{Value: 4.88, Label: "Green"},
{Value: 4.74, Label: "Gray"},
{Value: 3.22, Label: "Orange"},
{Value: 3, Label: "Test"},
{Value: 2.27, Label: "??"},
{Value: 1, Label: "!!"},
},
}
res.Header().Set("Content-Type", "image/png")
err := sbc.Render(chart.PNG, res)
if err != nil {
fmt.Printf("Error rendering chart: %v\n", err)
}
}
func port() string {
if len(os.Getenv("PORT")) > 0 {
return os.Getenv("PORT")
}
return "8080"
}
func main() {
listenPort := fmt.Sprintf(":%s", port())
fmt.Printf("Listening on %s\n", listenPort)
http.HandleFunc("/", drawChart)
log.Fatal(http.ListenAndServe(listenPort, nil))
}