How to download a file (iOS/Cocoa SDK) from URL where file name is not the part of URL

4
votes

I was wondering on how to download a file using NSUrl where the filename is not available or is not part of the request URL. I have been looking at ASIHTTPRequest (http://allseeing-i.com/ASIHTTPRequest/) library. It has 

ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
[request setDownloadDestinationPath:@"/Users/ben/Desktop/my_file.txt"];

But the point is you need to know the file name here. For example if you put the URL (not real URL) http://some-website/foo.pdf

It downloads a file foo.pdf and I want to save it like that. Any ideas thanks.

1
objective-ccocoaiosmacosiphone

1 Answers

5
votes

In the NSURLConnection delegate callback - (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response you can retrieve the suggestedFileName from the NSURLResponse. If you get unknown for a name then you need to come up with another name for your file. At this point you can specify your download path before you start saving data.

suggestedFilename

Returns a suggested filename for the response data.

  • (NSString *)suggestedFilename

Return Value

A suggested filename for the response data.

Discussion

The method tries to create a filename using the following, in order:

  1. A filename specified using the content disposition header.

  2. The last path component of the URL.

  3. The host of the URL.

If the host of URL can't be converted to a valid filename, the filename “unknown” is used.

In most cases, this method appends the proper file extension based on the MIME type. This method will always return a valid filename regardless of whether or not the resource is saved to disk.

Availability

Available in iOS 2.0 and later. Declared In NSURLResponse.h