package httpimg import ( "io" "net/http" "github.com/jung-kurt/gofpdf" ) // httpimgPdf is a partial interface that only implements the functions we need // from the PDF generator to put the HTTP images on the PDF. type httpimgPdf interface { GetImageInfo(imageStr string) *gofpdf.ImageInfoType ImageTypeFromMime(mimeStr string) string RegisterImageReader(imgName, tp string, r io.Reader) *gofpdf.ImageInfoType SetError(err error) } // Register registers a HTTP image. Downloading the image from the provided URL // and adding it to the PDF but not adding it to the page. Use Image() with the // same URL to add the image to the page. func Register(f httpimgPdf, urlStr, tp string) (info *gofpdf.ImageInfoType) { info = f.GetImageInfo(urlStr) if info != nil { return } resp, err := http.Get(urlStr) if err != nil { f.SetError(err) return } defer resp.Body.Close() if tp == "" { tp = f.ImageTypeFromMime(resp.Header["Content-Type"][0]) } return f.RegisterImageReader(urlStr, tp, resp.Body) }