[iOS, Objective-c] File Download (HTTP Response attachment)

webviewAttachmentFileDownload.m

#pragma mark - WKNavigationDelegate

- (void)webView:(WKWebView *)webView decidePolicyForNavigationResponse:(WKNavigationResponse *)navigationResponse decisionHandler:(void (^)(WKNavigationResponsePolicy))decisionHandler
{
    BOOL            sIsFileDownload         = NO;
    NSURL           *sURL                   = navigationResponse.response.URL;
    NSString        *sMIMEType              = navigationResponse.response.MIMEType;
    NSString        *sFileName              = navigationResponse.response.suggestedFilename;
    NSDictionary    *sHeaders               = ((NSHTTPURLResponse *)navigationResponse.response).allHeaderFields;
    NSString        *sContentDisposition    = sHeaders[@"Content-Disposition"];
    BOOL            sIsAttachment           = [sContentDisposition containsString:@"attachment"];
    BOOL            sIsSpreadSheetType      = [sMIMEType containsString:@"application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"];

    if (sIsSpreadSheetType || sIsAttachment)
    {
        NSURLRequest *sRequest = [NSURLRequest requestWithURL:sURL];
        [self downloadTaskFromRequest:sRequest fileName:sFileName];

        sIsFileDownload = YES;
    }
    else
    {
        sIsFileDownload = NO;
    }

    decisionHandler(sIsFileDownload ? WKNavigationResponsePolicyCancel : WKNavigationResponsePolicyAllow);
}