How can I upload a photo to a server with the iPhone?

Question

I'm writing an iPhone app that takes a photo and then uploads it to a server. How do I upload a photo to a server with Cocoa in Xcode? I suppose I use NSUrl somewhere.

Thanks!

Answer 1

You will have to be a lot more specific about what kind of server. Something you are creating yourself? An arbitrary FTP or WebDAV server? Flickr or Photobucket?

This doesn't sound like an iPhone-specific question. Once you explain more about the upload method, any desktop Cocoa examples will probably apply to Cocoa touch without modification.

Answer 2

Create an NSURLRequest and then use NSURLConnection to send it off to your server.

Answer 3

Header:

@interface EPUploader : NSObject {
    NSURL *serverURL;
    NSString *filePath;
    id delegate;
    SEL doneSelector;
    SEL errorSelector;

    BOOL uploadDidSucceed;
}

-   (id)initWithURL: (NSURL *)serverURL 
            filePath: (NSString *)filePath 
            delegate: (id)delegate 
        doneSelector: (SEL)doneSelector 
       errorSelector: (SEL)errorSelector;

-   (NSString *)filePath;

@end

Main:

#import "EPUploader.h"
#import <zlib.h>

static NSString * const BOUNDRY = @"0xKhTmLbOuNdArY";
static NSString * const FORM_FLE_INPUT = @"uploaded";

#define ASSERT(x) NSAssert(x, @"")

@interface EPUploader (Private)

- (void)upload;
- (NSURLRequest *)postRequestWithURL: (NSURL *)url
                             boundry: (NSString *)boundry
                                data: (NSData *)data;

- (NSData *)compress: (NSData *)data;
- (void)uploadSucceeded: (BOOL)success;
- (void)connectionDidFinishLoading:(NSURLConnection *)connection;

@end

@implementation EPUploader



/*
 *-----------------------------------------------------------------------------
 *
 * -[Uploader initWithURL:filePath:delegate:doneSelector:errorSelector:] --
 *
 *      Initializer. Kicks off the upload. Note that upload will happen on a
 *      separate thread.
 *
 * Results:
 *      An instance of Uploader.
 *
 * Side effects:
 *      None
 *
 *-----------------------------------------------------------------------------
 */

- (id)initWithURL: (NSURL *)aServerURL   // IN
         filePath: (NSString *)aFilePath // IN
         delegate: (id)aDelegate         // IN
     doneSelector: (SEL)aDoneSelector    // IN
    errorSelector: (SEL)anErrorSelector  // IN
{
    if ((self = [super init])) {
        ASSERT(aServerURL);
        ASSERT(aFilePath);
        ASSERT(aDelegate);
        ASSERT(aDoneSelector);
        ASSERT(anErrorSelector);

        serverURL = [aServerURL retain];
        filePath = [aFilePath retain];
        delegate = [aDelegate retain];
        doneSelector = aDoneSelector;
        errorSelector = anErrorSelector;

        [self upload];
    }
    return self;
}


/*
 *-----------------------------------------------------------------------------
 *
 * -[Uploader dealloc] --
 *
 *      Destructor.
 *
 * Results:
 *      None
 *
 * Side effects:
 *      None
 *
 *-----------------------------------------------------------------------------
 */

- (void)dealloc
{
    [serverURL release];
    serverURL = nil;
    [filePath release];
    filePath = nil;
    [delegate release];
    delegate = nil;
    doneSelector = NULL;
    errorSelector = NULL;

    [super dealloc];
}


/*
 *-----------------------------------------------------------------------------
 *
 * -[Uploader filePath] --
 *
 *      Gets the path of the file this object is uploading.
 *
 * Results:
 *      Path to the upload file.
 *
 * Side effects:
 *      None
 *
 *-----------------------------------------------------------------------------
 */

- (NSString *)filePath
{
    return filePath;
}


@end // Uploader


@implementation EPUploader (Private)


/*
 *-----------------------------------------------------------------------------
 *
 * -[Uploader(Private) upload] --
 *
 *      Uploads the given file. The file is compressed before beign uploaded.
 *      The data is uploaded using an HTTP POST command.
 *
 * Results:
 *      None
 *
 * Side effects:
 *      None
 *
 *-----------------------------------------------------------------------------
 */

- (void)upload
{
    NSData *data = [NSData dataWithContentsOfFile:filePath];
    ASSERT(data);
    if (!data) {
        [self uploadSucceeded:NO];
        return;
    }
    if ([data length] == 0) {
        // There's no data, treat this the same as no file.
        [self uploadSucceeded:YES];
        return;
    }

//  NSData *compressedData = [self compress:data];
//  ASSERT(compressedData && [compressedData length] != 0);
//  if (!compressedData || [compressedData length] == 0) {
//      [self uploadSucceeded:NO];
//      return;
//  }

    NSURLRequest *urlRequest = [self postRequestWithURL:serverURL
                                                boundry:BOUNDRY
                                                   data:data];
    if (!urlRequest) {
        [self uploadSucceeded:NO];
        return;
    }

    NSURLConnection * connection =
    [[NSURLConnection alloc] initWithRequest:urlRequest delegate:self];
    if (!connection) {
        [self uploadSucceeded:NO];
    }

    // Now wait for the URL connection to call us back.
}


/*
 *-----------------------------------------------------------------------------
 *
 * -[Uploader(Private) postRequestWithURL:boundry:data:] --
 *
 *      Creates a HTML POST request.
 *
 * Results:
 *      The HTML POST request.
 *
 * Side effects:
 *      None
 *
 *-----------------------------------------------------------------------------
 */

- (NSURLRequest *)postRequestWithURL: (NSURL *)url        // IN
                             boundry: (NSString *)boundry // IN
                                data: (NSData *)data      // IN
{
    // from http://www.cocoadev.com/index.pl?HTTPFileUpload
    NSMutableURLRequest *urlRequest =
    [NSMutableURLRequest requestWithURL:url];
    [urlRequest setHTTPMethod:@"POST"];
    [urlRequest setValue:
     [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundry]
      forHTTPHeaderField:@"Content-Type"];

    NSMutableData *postData =
    [NSMutableData dataWithCapacity:[data length] + 512];
    [postData appendData:
     [[NSString stringWithFormat:@"--%@\r\n", boundry] dataUsingEncoding:NSUTF8StringEncoding]];
    [postData appendData:
     [[NSString stringWithFormat:
       @"Content-Disposition: form-data; name=\"%@\"; filename=\"file.bin\"\r\n\r\n", FORM_FLE_INPUT]
      dataUsingEncoding:NSUTF8StringEncoding]];
    [postData appendData:data];
    [postData appendData:
     [[NSString stringWithFormat:@"\r\n--%@--\r\n", boundry] dataUsingEncoding:NSUTF8StringEncoding]];

    [urlRequest setHTTPBody:postData];
    return urlRequest;
}

/*
 *-----------------------------------------------------------------------------
 *
 * -[Uploader(Private) compress:] --
 *
 *      Uses zlib to compress the given data.
 *
 * Results:
 *      The compressed data as a NSData object.
 *
 * Side effects:
 *      None
 *
 *-----------------------------------------------------------------------------
 */

- (NSData *)compress: (NSData *)data // IN
{
    if (!data || [data length] == 0)
        return nil;

    // zlib compress doc says destSize must be 1% + 12 bytes greater than source.
    uLong destSize = [data length] * 1.001 + 12;
    NSMutableData *destData = [NSMutableData dataWithLength:destSize];

    int error = compress([destData mutableBytes],
                         &destSize,
                         [data bytes],
                         [data length]);
    if (error != Z_OK) {
        NSLog(@"%s: self:0x%p, zlib error on compress:%d\n",__func__, self, error);
        return nil;
    }

    [destData setLength:destSize];
    return destData;
}


/*
 *-----------------------------------------------------------------------------
 *
 * -[Uploader(Private) uploadSucceeded:] --
 *
 *      Used to notify the delegate that the upload did or did not succeed.
 *
 * Results:
 *      None
 *
 * Side effects:
 *      None
 *
 *-----------------------------------------------------------------------------
 */

- (void)uploadSucceeded: (BOOL)success // IN
{
    [delegate performSelector:success ? doneSelector : errorSelector
                   withObject:self];
}


/*
 *-----------------------------------------------------------------------------
 *
 * -[Uploader(Private) connectionDidFinishLoading:] --
 *
 *      Called when the upload is complete. We judge the success of the upload
 *      based on the reply we get from the server.
 *
 * Results:
 *      None
 *
 * Side effects:
 *      None
 *
 *-----------------------------------------------------------------------------
 */

- (void)connectionDidFinishLoading:(NSURLConnection *)connection // IN
{
    NSLog(@"%s: self:0x%p\n", __func__, self);
    [connection release];
    [self uploadSucceeded:uploadDidSucceed];
}


/*
 *-----------------------------------------------------------------------------
 *
 * -[Uploader(Private) connection:didFailWithError:] --
 *
 *      Called when the upload failed (probably due to a lack of network
 *      connection).
 *
 * Results:
 *      None
 *
 * Side effects:
 *      None
 *
 *-----------------------------------------------------------------------------
 */

- (void)connection:(NSURLConnection *)connection // IN
  didFailWithError:(NSError *)error              // IN
{
    NSLog(@"%s: self:0x%p, connection error:%s\n",
            __func__, self, [[error description] UTF8String]);
    [connection release];
    [self uploadSucceeded:NO];
}


/*
 *-----------------------------------------------------------------------------
 *
 * -[Uploader(Private) connection:didReceiveResponse:] --
 *
 *      Called as we get responses from the server.
 *
 * Results:
 *      None
 *
 * Side effects:
 *      None
 *
 *-----------------------------------------------------------------------------
 */

-(void)       connection:(NSURLConnection *)connection // IN
      didReceiveResponse:(NSURLResponse *)response     // IN
{
    NSLog(@"%s: self:0x%p\n", __func__, self);
}


/*
 *-----------------------------------------------------------------------------
 *
 * -[Uploader(Private) connection:didReceiveData:] --
 *
 *      Called when we have data from the server. We expect the server to reply
 *      with a "YES" if the upload succeeded or "NO" if it did not.
 *
 * Results:
 *      None
 *
 * Side effects:
 *      None
 *
 *-----------------------------------------------------------------------------
 */

- (void)connection:(NSURLConnection *)connection // IN
    didReceiveData:(NSData *)data                // IN
{
    NSLog(@"%s: self:0x%p\n", __func__, self);

    NSString *reply = [[[NSString alloc] initWithData:data
                                             encoding:NSUTF8StringEncoding]
                       autorelease];
    NSLog(@"%s: data: %s\n", __func__, [reply UTF8String]);

    if ([reply hasPrefix:@"YES"]) {
        uploadDidSucceed = YES;
    }
}


@end

Usage:

        [[EPUploader alloc] initWithURL:[NSURL URLWithString:@"http://yourserver.com/uploadDB.php"]
                                                     filePath:@"path/to/some/file"
                                                     delegate:self
                                                 doneSelector:@selector(onUploadDone:)
                                                errorSelector:@selector(onUploadError:)];       

Answer 4

Looks like Three20 library has support for POSTing images to HTTP server.

See TTURLRequest.m

And it's released under Apache 2.0 License.

Answer 5

Sridhar,

a PHP web application:

The following PHP code receives the name of the file in the "uploaded" parameter. If uploading was successful then the file is copied into the upload directory. Save this code as uploader.php and put it on your webserver.

 <?php
    $target = "upload/";
    $target = $target . basename( $_FILES['uploaded']['name']) ;
    $ok=1;
    if(move_uploaded_file($_FILES['uploaded']['tmp_name'], $target))
    {
       echo "YES";
    }
    else {
       echo "NO";
    }
    ?>

If you're having trouble getting your web application to work it may help to test it using a web browser. You can create a web page to upload a file using the following code. Same the code as test.php and put it on your webserver.

 <form enctype="multipart/form-data" action="uploader.php" method="POST">
    <input type="hidden" name="MAX_FILE_SIZE" value="100000" />
    Choose a file to upload: <input name="uploaded" type="file" /><br />
    <input type="submit" value="Upload File" />
    </form>