Flutter url_launcher - how to force download pdf link?

Question

I'm trying to force download a pdf file when the link is clicked. For some links, it works. But other pdf links, it just shows pdf in the browser. I'd appreciate if you could help! Thanks 😊

Answer 1

1st way

it's managed from the URL. I think. you can check this link. because that download URL contains some header based on that browser performing an action.

show file in browser:

Content-Type: application/pdf
Content-Disposition: inline; filename="filename.pdf"

download file in browser

Content-Type: application/pdf Content-Disposition: attachment;
filename="filename.pdf"

so basically you need to manage this in URL.

2nd way you can also directly download files from URL

Web download option

import 'dart:html' as html;
void downloadFile(String url) {
   html.AnchorElement anchorElement =  new html.AnchorElement(href: url);
   anchorElement.download = url;
   anchorElement.click();
}

If you want to Download and Save files from URL without external libraries. mobile platform

Future<String> downloadFile(String url, String fileName, String dir) async {
     HttpClient httpClient = new HttpClient();
     File file;
     String filePath = '';
     String myUrl = '';
            
   try {
          myUrl = url+'/'+fileName;
          var request = await httpClient.getUrl(Uri.parse(myUrl));
          var response = await request.close();
         if(response.statusCode == 200) {
                    var bytes = await consolidateHttpClientResponseBytes(response);
                    filePath = '$dir/$fileName';
                    file = File(filePath);
                    await file.writeAsBytes(bytes);
              } else
                    filePath = 'Error code:'+response.statusCode.toString();
            } catch(ex){
                  filePath = 'Can not fetch url';
      }
            
       return filePath;
}