How to Create UIImage from NSData and Avatar Data of XMPP? - iphone

Question

This question is related to Iphone SDK, NSData and UIImage.
I am trying to create an image from the Avatar Data returned from the xmpp like the following:
<presence from='yyy#184.73.164.51/spark' to='ken#184.73.164.51/424978324712783686768453' id='Oj02v-45'><status>Away due to idle.</status><priority>0</priority><show>away</show><x xmlns='vcard-temp:x:update'><photo>a3f549fa9705e7ead2905de0b6a804227ecdd404</photo></x><x xmlns='jabber:x:avatar'><hash>a3f549fa9705e7ead2905de0b6a804227ecdd404</hash></x></presence>
So in this case, I assume that a3f549fa9705e7ead2905de0b6a804227ecdd404 is the photo data.
So How can I transfer this into NSData?
I think if I can get the NSData object,
I can easily create the UIImage, right?
I think "a3f549fa9705e7ead2905de0b6a804227ecdd404" is the photo data
this is my codes:
NSString* command = #"a3f549fa9705e7ead2905de0b6a804227ecdd404";
command = [command stringByReplacingOccurrencesOfString:#" " withString:#""];
NSMutableData *commandToSend= [[NSMutableData alloc] init];
unsigned char whole_byte;
char byte_chars[3] = {'\0','\0','\0'};
int i;
for (i=0; i < [command length]/2; i++) {
byte_chars[0] = [command characterAtIndex:i*2];
byte_chars[1] = [command characterAtIndex:i*2+1];
whole_byte = strtol(byte_chars, NULL, 16);
[commandToSend appendBytes:&whole_byte length:1];
}
UIImage *image = [UIImage imageWithData: commandToSend];
However,
it doesn't work.
Anyone knows what's wrong with it?

Answer 1

In XMPPPresence.m add this method
-(NSString *)photo {
NSXMLElement *xElement = [self elementForName:#"x" xmlns:#"vcard-temp:x:update"];
NSString *photoHash = [[xElement elementForName:#"photo"]stringValue];
return photoHash;
}
// In XMPPStream's delegate:
- (void)xmppStream:(XMPPStream *)stream didReceivePresence:
(XMPPPresence *)presence {
NSString *photoHash = [presence photo];
if ([photoHash length] > 0) { // in case when there's no photo hash
XMPPJID *rosterJID = [presence from];
BOOL requestPhoto = ... // determine if you need to request new
photo or nor
if (requestPhoto) {
NSXMLElement *iqAvatar = [NSXMLElement elementWithName:#"iq"];
NSXMLElement *queryAvatar = [NSXMLElement elementWithName:#"vCard"
xmlns:#"vcard-temp"];
[iqAvatar addAttributeWithName:#"type" stringValue:#"get"];
[iqAvatar addAttributeWithName:#"to" stringValue:[rosterJID full]];
[iqAvatar addChild:queryAvatar];
XMPPIQ *avatarRequestIQ = [XMPPIQ iqFromElement:iqAvatar];
[stream sendElement:avatarRequestIQ];
}
}
}
// And when buddy will send photo, it will be in vcard BASE64-encoded.
// You will receive it as IQ:
- (BOOL)xmppStream:(XMPPStream *)stream didReceiveIQ:(XMPPIQ *)iq {
XMPPElement *vCardPhotoElement = (XMPPElement *)[[iq
elementForName:#"vCard"] elementForName:#"PHOTO"];
if (vCardPhotoElement != nil) {
// avatar data
NSString *base64DataString = [[vCardPhotoElement
elementForName:#"BINVAL"] stringValue];
NSData *imageData = [NSData
dataFromBase64String:base64DataString]; // you need to get NSData
BASE64 category
UIImage *avatarImage = [UIImage imageWithData:imageData];
XMPPJID *senderJID = [iq from];
[self xmppStream:stream didReceiveImage:avatarImage
forBuddy:senderJID]; // this is my custom delegate method where I
save new avatar to cache
}
return NO;
}
Hope this will help you.

Answer 2

That is the picture hash you now have to send a vcard request which will contain the same hash for verification and binval containing the picture data in base64