docs: update readme

examples/basic/main.go

@@ -0,0 +1,91 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+
+	charts "github.com/vicanso/go-charts"
+)
+
+func writeFile(file string, buf []byte) error {
+	tmpPath := "./tmp"
+	err := os.MkdirAll(tmpPath, 0700)
+	if err != nil {
+		return err
+	}
+
+	file = filepath.Join(tmpPath, file)
+	err = os.WriteFile(file, buf, 0600)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func chartsRender() ([]byte, error) {
+	d, err := charts.Render(charts.ChartOption{
+		Type: charts.ChartOutputPNG,
+		Title: charts.TitleOption{
+			Text: "Line",
+		},
+		XAxis: charts.NewXAxisOption([]string{
+			"Mon",
+			"Tue",
+			"Wed",
+			"Thu",
+			"Fri",
+			"Sat",
+			"Sun",
+		}),
+		SeriesList: charts.SeriesList{
+			charts.NewSeriesFromValues([]float64{
+				150,
+				230,
+				224,
+				218,
+				135,
+				147,
+				260,
+			}),
+		},
+	})
+	if err != nil {
+		return nil, err
+	}
+	return d.Bytes()
+}
+
+func echartsRender() ([]byte, error) {
+	return charts.RenderEChartsToPNG(`{
+		"title": {
+			"text": "Line"
+		},
+		"xAxis": {
+			"data": ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]
+		},
+		"series": [
+			{
+				"data": [150, 230, 224, 218, 135, 147, 260]
+			}
+		]
+	}`)
+}
+
+type Render func() ([]byte, error)
+
+func main() {
+	m := map[string]Render{
+		"charts-line.png":  chartsRender,
+		"echarts-line.png": echartsRender,
+	}
+	for name, fn := range m {
+		buf, err := fn()
+		if err != nil {
+			panic(err)
+		}
+		err = writeFile(name, buf)
+		if err != nil {
+			panic(err)
+		}
+	}
+}