CODEWITHSUNDEEP
iosobjective-cjsonnsarraynsuserdefaults
AndroidDev
AndroidDev

Reputation: 21237

Converting NSString to NSArray and storing in NSUserdefaults

I have a string that downloads from a server. It is in JSON format and is well-formed. It is an array of JSON objects. My objective is to convert this to an NSArray and then store it in NSUserDefaults for subsequent use. My attempt generally works, but sometimes I crash with this error:

Attempt to set a non-property-list object

Here is the code that I am using. I think that it should be this straightforward. I don't believe have to actually convert the objects to NSDictionaries and iterate over this, do I?

NSString *message = [dict objectForKey:@"message"];
NSLog(@"message: %@", message);
data = [message dataUsingEncoding:NSUTF8StringEncoding];
NSArray *arr = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];

[[NSUserDefaults standardUserDefaults] setObject:arr forKey:RESOURCES_LIST];

For example, this is one of the strings that causes this to crash (as output by the NSLog command):

[{"folder":"Documents","files":[{"sort_order":"120","filename":"pdf.pdf","filetype":"pdf","display_name":"Instructions","upload_date":"2015-08-11","md5":"ea9f839f91941b5ea7f5a316e3ce95ca","bool_external":"0","url":"http://www.somesite.com/pdf.pdf"}]},{"folder":"Images","files":[{"sort_order":"100","filename":"space.jpg","filetype":"image","display_name":"example","upload_date":"2015-10-14","md5":"bc63b896949cbf87c54678fee8ed833b","bool_external":"0","url":"http://www.somesite.com/space.jpg"},{"sort_order":"110","filename":"profile.png","filetype":"image","display_name":"Profile","upload_date":"2015-10-14","md5":"740d61911560e1c84869563b83f3bbf8","bool_external":"0","url":"http://www.somesite.com/profile.jpeg"}]},{"folder":"Info","files":[{"sort_order":"130","filename":"info.pdf","filetype":"pdf","display_name":"info","upload_date":"2015-11-17","md5":"926a7941cc9c7f58e43c3eb2de661c27","bool_external":"0","url":null}]},{"folder":"Videos","files":[{"sort_order":"130","filename":"sample_video","filetype":"video","display_name":"Instructional Video","upload_date":"2015-08-11","md5":"-1","bool_external":"0","url":"https://www.youtube.com/embed/PuNIwSsz7PI"}]}]

Upvotes: 0

Views: 89

Answers (1)

Kevin
Kevin

Reputation: 56089

            "url": null

(in [2][@"files"][0]) This is likely being parsed into a value of [NSNull null], which cannot be stored in NSUserDefaults. You will need to either change the server to send as an empty string or not at all, or (recursively) iterate and check all values, removing (or replacing with @"") all keys with value [NSNull null].

For reference, the acceptable classes in plist files and NSUserDefaults are:

  • Array (NSArray)
  • Dictionary (NSDictionary)
  • String (NSString)
  • Data (NSData)
  • Date (NSDate)
  • Numerics [int32/64, float/double] (NSNumber)
  • Boolean (NSNumber)

And keys must be strings.

Upvotes: 1

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