snapshot-chromedp

⚔️ The extension for render image of go-echarts.

The snapshot-chromedp is powered by the chromedp which enable to snapshot charts in HTML to images.
chromedp is a faster, simpler way to drive browsers supporting the Chrome DevTools Protocol, which means this extension works under Chrome DevTools Protocol supporting.

Install

Support since go-echarts v2.4.0-rc1

require github.com/go-echarts/snapshot-chromedp v0.0.4

Configuration

Normally, if you only need render the chart to image, the handy call is enough.

    render.MakeChartSnapshot(myChart.RenderContent(), "my-chart.png")

By default, it will generate the HTML content first and do the snapshot, clean the HTML then.

If you want to have full control on it, the whole config list here.

type SnapshotConfig struct {
    // RenderContent the content bytes of charts after rendered
    RenderContent []byte
    // Path the path to save image
    Path string
    // FileName image name
    FileName string
    // Suffix image format, png, jpeg
    Suffix string
    // Quality the generated image quality, aka pixelRatio
    Quality int
    // KeepHtml whether keep the generated html also, default false
    KeepHtml bool
    // HtmlPath where to keep the generated html, default same to image path
    HtmlPath string
    // Timeout  the timeout config
    Timeout time.Duration
}

Example

[!NOTE] You must disable the chart's Animation option to ensure the chart being rendered immediately.

package main

import (
    "github.com/go-echarts/go-echarts/v2/charts"
    "github.com/go-echarts/go-echarts/v2/opts"
    "github.com/go-echarts/snapshot-chromedp/render"
    "math/rand"
)

var (
    itemCnt = 7
    weeks   = []string{"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"}
)

func generateBarItems() []opts.BarData {
    items := make([]opts.BarData, 0)
    for i := 0; i < itemCnt; i++ {
        items = append(items, opts.BarData{Value: rand.Intn(300)})
    }
    return items
}

func barTitle() *charts.Bar {
    bar := charts.NewBar()
    bar.SetGlobalOptions(
        charts.WithInitializationOpts(opts.Initialization{
            BackgroundColor: "#FFFFFF",
        }),
        // Don't forget disable the Animation
        charts.WithAnimation(false),
        charts.WithTitleOpts(opts.Title{
            Title:    "title and legend options",
            Subtitle: "go-echarts is an awesome chart library written in Golang",
            Link:     "https://github.com/go-echarts/go-echarts",
            Right:    "40%",
        }),
        charts.WithLegendOpts(opts.Legend{Right: "80%"}),
    )
    bar.SetXAxis(weeks).
        AddSeries("Category A", generateBarItems()).
        AddSeries("Category B", generateBarItems())
    return bar
}

func barTooltip() *charts.Bar {
    bar := charts.NewBar()
    bar.SetGlobalOptions(
        charts.WithAnimation(false),
        charts.WithTitleOpts(opts.Title{Title: "tooltip options"}),
        charts.WithLegendOpts(opts.Legend{Right: "80px"}),
    )
    bar.SetXAxis(weeks).
        AddSeries("Category A", generateBarItems()).
        AddSeries("Category B", generateBarItems())
    return bar
}

func main() {
    barTitleChart := barTitle()
    barTooltipChart := barTooltip()
    render.MakeChartSnapshot(barTitleChart.RenderContent(), "my-bar-title.png")
    render.MakeChartSnapshot(barTooltipChart.RenderContent(), "my-bar-tooltip.jpg")
}

It only supports single charts for now, multi charts in one Page is WIP.

Special Thanks

chromedp

License

MIT @Koooooo-7