角2/4手柄res.download

Question

I ran into a problem with downloading a file with angular.

When using Postman the File shows correctly in the body.

I am using the express function res.download and I can get the file to download but it is not a working png what am I doing wrong?

My Angular 4 implimentation:

        this.http.post(localhost,{"jabcontent": cert._id})
        .subscribe(
            data => {
                console.log(data.text());
                var blob = new Blob([data.text()], {type: "image/png"});
                FileSaver.saveAs(blob, "test.png" );
                /* var blob = new Blob([data.text()], {type: "image/png"});
                var objectUrl = URL.createObjectURL(blob);
                window.open(objectUrl); */
            }
        )

Answer 1

I figured it out.

My backend was correct:

         res.download(pathtoFile, filename, (err) => {
            //err handeling
        }); 

I did a mistake with the handeling of the respons. The mapping of the response was not correct also i set the response type to blob. The switch to get was for consistency sake.

    var headers = new Headers();
    headers.append('xyz', '1234'); //request parameter
    let options = new RequestOptions({ headers: headers, responseType: ResponseContentType.Blob });
    this.http.get('apipath', options)
        .map((response: Response)=> response.blob())
        .subscribe(data => {
            FileSaver.saveAs(data, "filename");
        }
        );