A humane JSON Objective-C un-framework. (TouchJSON has been deprecated - see README)
TouchJSON is an Objective-C based parser and generator for JSON encoded data. TouchJSON compiles for
Mac OS X and iOS devices (currently iPhone, iPad and iPod Touch).
It is based on Jonathan Wight’s CocoaJSON code: http://toxicsoftware.com/cocoajson/
TouchJSON was deprecated but is now back from the dead. I’ll be updating the
README and explaining why soon.
See LICENSE file.
The “master” branch of TouchJSON now uses ARC.
The “feature/nonARC” branch is deprecated and no more fixes will be made to it. You’re welcome to
use it if it works for you but no bugs will be accepted and no changes made.
The main source repository for touchcode is on github at http://github.com/TouchCode/TouchJSON
The primary author is Jonathan Wight http://toxicsoftware.com/ with several other people
contributing bug fixes, patches and documentation. (Note: if you have contributed to TouchJSON and
want to be listed here let Jonathan Wight know).
There’s a relatively low traffic mailing list hosted on Google Groups:
http://groups.google.com/group/touchcode-dev
File bugs on the github issue tracker http://github.com/TouchCode/TouchJSON/issues but please make
sure that your JSON data is valid (see http://www.jsonlint.com/ before filing bugs (of course if
you’ve found a crash with TouchJSON’s handling of invalid JSON feel free to file a bug or discuss on
the mailing list).
There are many things you can do to help TouchJSON
TouchJSON is incredibly easy to use. Usually you can convert JSON data to and from a Cocoa
representation in just a line of code.
None! TouchJSON compiles on Mac OS X (note it does use ObjC-2) and iOS. It should compile on all
versions of iOS to date.
Note that the demo, unit tests and bench-marking projects run on Mac OS X.
Copy the source files within TouchJSON/Source to your project.
The easiest way is to open both projects in Xcode, then drag and drop. Make sure to check “Copy
items into destination groups folder (if needed).”
Be aware that the code in the Experimental subdirectory of Source is just that and may not have been
extensively tested and/or have extra dependencies
Put #import “CJSONDeserializer.h” in your source file.
NSData *theJSONData = /* some JSON data */
NSError *theError = nil;
id theObject = [[CJSONDeserializer deserializer] deserialize:theJSONData error:&theError];}
This will convert an NSData object containing JSON into an object. The resulting object’s class
depends on the type of JSON data in question. If the object is NULL then deserialization has failed
and you should check the error parameter.
The following, slightly more complex example shows how to convert an NSString containing a JSON
dictionary into an NSDictionary:
NSString *jsonString = @"yourJSONHere";
NSData *jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
NSError *error = nil;
NSDictionary *dictionary = [[CJSONDeserializer deserializer] deserializeAsDictionary:jsonData error:&error];
This deserialization will fail if the JSON root object is not a dictionary. Again check the error.
Put #include “NSDictionary_JSONExtensions.h” in your source file.
NSString *theJSONString = @"{\"key\":\"value\"}";
NSError *theError = NULL;
NSDictionary *theDictionary = [NSDictionary dictionaryWithJSONString:theJSONString error:&theError];
This version of the code could be considered more convenient than the above former examples.
If your input JSON data contains null values these values will, by default, be represented by NSNull
in your output ObjC objects. The following example shows you how to avoid NSNull values in your
output:
NSData *theJSONData = /* some JSON data */
CJSONDeserializer *theDeserializer = [CJSONDeserializer deserializer];
theDeserializer.nullObject = NULL;
NSError *theError = nil;
id theObject = [theDeserializer deserialize:theJSONData error:&theError];}
Put #import “CJSONDataSerializer.h” in your file.
Here is a code sample:
NSDictionary *dictionary = [NSDictionary dictionaryWithObject:@"b" forKey:@"a"];
NSError *error = NULL;
NSData *jsonData = [[CJSONSerializer serializer] serializeObject:dictionary error:&error];
If you think your JSON is valid but TouchJSON is failing to process it correctly (or if you think
TouchJSON is producing invalid JSON) use the online JSON lint tool to validate your JSON:
http://www.jsonlint.com/
It is especially important to validate your JSON before filing bugs.
TouchJSON will work with JSON with any string encoding supported by the Foundation framework.
However internally TouchJSON prefers UTF8, so for performance purposes you should try to use UTF8 if
at all possible.
JSON doesn’t specify a date encoding format. As such various methods are used. As such TouchJSON
doesn’t dictate which format you use. ISO 8601 style dates (with as much precession as needed) are
recoemmended. See http://en.wikipedia.org/wiki/ISO_8601. You can use the CFilteringJSONSerializer
class to automatically serialize Cocoa’s NSDate objects into ISO-8601 strings