I'm playing around with chromedp and been trying to replicate the functionality in puppeteer node.js but in golang.
I'm finding that the same JSON payload to chromium is causing an error when using chromedp
package main
import (
"context"
"io/ioutil"
"log"
"github.com/chromedp/cdproto/page"
"github.com/chromedp/chromedp"
)
func main() {
// create context
ctx, cancel := chromedp.NewContext(context.Background())
defer cancel()
// capture pdf
var buf []byte
if err := chromedp.Run(ctx, printToPDF(`<html><body><h1>Yeeeew!</h1></body></html>`, &buf)); err != nil {
log.Fatal(err)
}
if err := ioutil.WriteFile("sample.pdf", buf, 0644); err != nil {
log.Fatal(err)
}
}
// https://github.com/puppeteer/puppeteer/blob/4d9dc8c0e613f22d4cdf237e8bd0b0da3c588edb/src/common/PDFOptions.ts#L74
// https://github.com/puppeteer/puppeteer/blob/4d9dc8c0e613f22d4cdf237e8bd0b0da3c588edb/src/common/Page.ts#L3366
//https://github.com/chromedp/chromedp/issues/836
func printToPDF(html string, res *[]byte) chromedp.Tasks {
return chromedp.Tasks{
chromedp.Navigate("about:blank"),
chromedp.ActionFunc(func(ctx context.Context) error {
frameTree, err := page.GetFrameTree().Do(ctx)
if err != nil {
return err
}
return page.SetDocumentContent(frameTree.Frame.ID, html).Do(ctx)
}),
chromedp.ActionFunc(func(ctx context.Context) error {
buf, _, err := page.PrintToPDF().
// WithPrintBackground(false).
WithMarginTop(20.0).
// WithMarginLeft(20).
// WithMarginBottom(20.0).
// WithMarginRight(20).
Do(ctx)
if err != nil {
return err
}
*res = buf
return nil
}),
}
}
I've vendored the modules and edited cdproto/page/page.go to print out the JSON being sent to chromium
{"marginTop":20,"marginBottom":0,"marginLeft":0,"marginRight":0,"transferMode":"ReturnAsStream"}
I've also done this in node.js and logged out the json to compare
node index.js
PDF command: 'Page.printToPDF' {
transferMode: 'ReturnAsStream',
marginTop: 20,
marginBottom: 20,
marginLeft: 0,
marginRight: 0
}
I'm not sure why I'm getting this error? Any ideas?
