CODEWITHSUNDEEP
objective-ciosjsonnsdictionarynsdata
Firdous
Firdous

Reputation: 4652

Not able to read JSON from service

I am implementing forget password service in which I would pass an email address and it would return JSON to acknowledge about the sent email. The issue is that I am unable to read the response string in json, and my exception message is shown that data parameter is nil, but if I view the url in my web browser the service looks fine as mentioned below. my code is:

NSURL *url = [LokalmotionCommonTask getURLForgotPassword:emailFieldTxt.text];

    NSData* data = [NSData dataWithContentsOfURL: url];

    @try {
        NSError* error;
        NSDictionary* jsonDict = [NSJSONSerialization 
                                  JSONObjectWithData:data //1
                                  options:0 
                                  error:&error];

        NSLog(@"%@", [jsonDict objectForKey:@"response"]);
    }
    @catch (NSException *exception) {
        NSLog(@"forgot password exception: %@: %@", [exception name], [exception reason]);
    }

and the service response I get in my web browser is like this:

{"status":400,"response":"Your request to change password is already sent. Please check your email."}

Exception:

forgot password exception: NSInvalidArgumentException: data parameter is nil

Upvotes: 3

Views: 2452

Answers (4)

iGauravK
iGauravK

Reputation: 91

i was facing the same problem, problem was that i have given extra space in the url string that was url string @" http:...." corrected it by removing space in the start of url string @"https:...."

Upvotes: 1

Firdous
Firdous

Reputation: 4652

Solved that by fixing service URL, my url was not encoded and had spaces inline

Upvotes: 0

Christian Schnorr
Christian Schnorr

Reputation: 10776

There error says data parameter is nil. So the variable you pass for the JSON-date probably is nil.
[NSData dataWithContentsOfURL:url] probably returns nil since an error occured. Try logging that.

Also, even if it is only a small file you request, I would go for an asynchronous request in order not to block the UI.

Upvotes: 1

zaph
zaph

Reputation: 112857

in Objective-C exceptions are only used for fatal errors, not recoverable errors. Instead just check for nil data:

If you need to know what was the reason for failure, use: 

NSError* error;
NSURL *url = [LokalmotionCommonTask getURLForgotPassword:emailFieldTxt.text];
NSData* data = [NSData dataWithContentsOfURL: url options:NULL error:&error];
if (data) {
    NSDictionary* jsonDict = [NSJSONSerialization 
                              JSONObjectWithData:data //1
                              options:0 
                              error:&error];
    NSLog(@"%@", [jsonDict objectForKey:@"response"]);
}
else {
    NSLog(@"forgot password error, %@", [error localizedFailureReason]);
}

There is a naming convention error: getURLForgotPassword:
A method name that begins with "get" implies that there will be a return by reference parameter. Better to just name the method: forgotPasswordURL:

These two things, exceptions and accessors prefixed with get are a basic difference from Jave.

Upvotes: 3

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