converting image to base64 and uploading in JSON format to server - iphone

Question

I have a problem. I need to convert base64 string to JSON string and pass it to server.
for example I have a base64 string /9j/4AAQSkZJRgABAQAAAQABAAD/4QBYRXhpZgAATU0AKgAAAAgAAgESAAMAAAABAAEAAIdpAAQAAAABAAAAJgAAAAAAA6ABAAMAAAABAAEAAKACAAQAAAABAAAACqADAAQAAAABAAAACgAAAAD/2wBDAAEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQH/Z
i need to convert it to JSON format. I do the following:
+(NSData *)prepareForUploading:(NSString *)base64Str
{
NSDictionary *dict=[NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:base64str, nil] forKeys:[NSArray arrayWithObjects:#"picture", nil]];
NSData *preparedData=[NSJSONSerialization dataWithJSONObject:dict options:NSJSONWritingPrettyPrinted error:nil];
return preparedData;
};
here how I'm making NSURLRequest
-(NSString *)uploadPict:(NSString *)pict
{
NSLog(#"Server: upload: called");
NSData *prepPictData=[[self class] prepareForUploading:pict];
NSString *preparedBase64StrInJSON=[[NSString alloc] initWithData:prepPictData encoding:NSUTF8StringEncoding];
//here I'm adding access token to request
NSString *post = [NSString stringWithFormat:#"accessToken=%#&object=%#", self.key, preparedBase64StrInJSON];
NSData *postData = [post dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];
NSString *postLength = [NSString stringWithFormat:#"%d", [postData length]];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
[request setURL:[NSURL URLWithString:[NSString stringWithFormat:#"%#upload.aspx", serverAPIPath]]];
[request setHTTPMethod:#"POST"];
[request setValue:#"postLength" forHTTPHeaderField:#"Content-Length"];
[request setValue:#"application/x-www-form-urlencoded" forHTTPHeaderField:#"Content-Type"];
[request setHTTPBody:postData];
NSURLResponse *response;
NSError *error;
NSData *urlData=[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
//....
}
But I get "Invalid length for a Base-64 char array" from server. What's wrong?
If I paste my token and JSON to http://hurl.it/ and make request using it - everything goes normally.
I think the problem is / symbols in base64 string and as a result / symbols in JSON.
Maybe it is something with [postData length]: if I erase \/ characters from JSON string:
9j4AAQSkZJRgABAQAAAQABAAD4QBYRXhpZgAATU0AKgAAAAgAAgESAAMAAAABAAEAAIdpAAQAAAABAAAAJgAAAAAAA6ABAAMAAAABAAEAAKACAAQAAAABAAAACqADAAQAAAABAAAACgAAAAD2wBDAAEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQHZ request will perform normally but this base64 encoded string is not the same.
Please, help me to solve this problem

Answer 1

jString is your base64 string, first use following line
[self encodeString:jString];
and then call use following.
NSString *URL = [NSString stringWithFormat:#"forms.asmx/CreateUpdate?"];
URL=[NSString stringWithFormat:#"%#%#", USERS_API_ROOT_URL, URL];
NSString *post = [NSString stringWithFormat:#"apiKey=A0B1I2L3A4L5-A1D3-4F30-5AB2-C8DEE266&strPost=%#",jString];
unsigned long long postLength = [post length];
NSString *contentLength = [NSString stringWithFormat:#"%llu",postLength];
NSData *postData = [post dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init] ;
[request setURL:[NSURL URLWithString:URL]];
[request setHTTPMethod:#"POST"];
[request setValue:contentLength forHTTPHeaderField:#"Content-Length"];
[request setValue:#"application/x-www-form-urlencoded" forHTTPHeaderField:#"Content-Type"];
[request setHTTPBody:postData ];
(void)[[NSURLConnection alloc] initWithRequest:request delegate:self];
-(NSString *)encodeString:(NSString *)string
{
NSString *newString = (__bridge_transfer NSString*)CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, (CFStringRef)string, NULL,CFSTR(":/?#[]#!$ &'()*+,;=\"<>%{}|\\^~`"), CFStringConvertNSStringEncodingToEncoding(NSUTF8StringEncoding));
return newString;
}
Hope it will work.