when I try to write this JSON:
{"author":"mehdi","email":"email#hotmail.fr","message":"Hello"}
like this in Objective-C:
NSString *myJson=#"{"author":"mehdi","email":"email#hotmail.fr","message":"Hello"}";
it doesn't work. Can someone help me?
You need to escape quote characters with a backslash:
NSString *myJson = #"{\"author\":\"mehdi\",\"email\":\"email#hotmail.fr\",\"message\":\"Hello\"}";
Otherwise the compiler will think that your string literal ends right after the first {.
The backslashes will not be present as characters in the resulting NSString. They are merely there as hints for the compiler and are removed from the actual string during compilation.
Newbie note: JSON strings that you read directly from a file via Objective C of course do not need any escaping! (JSON itself may need such, but that's about it. No need for additional escaping on the ObjC-side of it.)
Related
I am looking for a way to decode quoted-printables.
The quoted-printables are for arabic characters and look like this:
=D8=B3=D8=B9=D8=A7=D8=AF
I need to convert it to a string, and store it or display..
I've seen post on stackoverflow for the other way around (encoding), but couldn't find decoding.
Uhm, it's a little hacky but you could replace the = characters with a % character and use NSString's stringByReplacingPercentEscapesUsingEncoding: method. Otherwise, you could essentially split the string on the = characters, convert each element to a byte value (easily done using NSScanner), put the byte values into a C array, and use NSString's initWithBytes:length:encoding: method.
Note that your example isn't technically in quoted-printable format, which specifies that a quoted-printable is a three character sequence consisting of an = character followed by two hex digits.
In my case I was coming from EML... bensnider's answer worked great... quoted-printable (at least in EML) uses an = sign followed by \r\n to signify a line wrapping, so this was the code needed to cleanly translate:
(Made as a category cause I loves dem)
#interface NSString (QuotedPrintable)
- (NSString *)quotedPrintableDecode;
#end
#implementation NSString (QuotedPrintable)
- (NSString *)quotedPrintableDecode
{
NSString *decodedString = [self stringByReplacingOccurrencesOfString:#"=\r\n" withString:#""]; // Ditch the line wrap indicators
decodedString = [decodedString stringByReplacingOccurrencesOfString:#"=" withString:#"%"]; // Change the ='s to %'s
decodedString = [decodedString stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding]; // Replace the escaped strings.
return decodedString;
}
#end
Which worked great for decoding my EML / UTF-8 objects!
Bensnider's answer is correct, the easy way of it.
u'll need to replace the "=" to "%"
NSString *s = #"%D8%B3%D8%B9%D8%A7%D8%AF";
NSString *s2 = [s stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
s2 stored "سعاد" which makes sense so this should work straight forward with out a hack
In some cases the line ends are not "=\r\n" but are only "=\n", in which case you need another step:
decodedString = [self stringByReplacingOccurrencesOfString:#"=\n" withString:#""];
Otherwise, the final step fails due to the unbalanced "%" at the end of a line.
I know nothing of the iPhone, but most email processing libraries will contain functions to do this, as email is where this format is used. I suggest searching for MIME decoding type functions, similar to those at enter link description here.
The earlier posters approach also seems fine to me - I feel he is being a little too self-deprecating in describing it as hacky :)
Please see a working solution that takes a quoted-printable-containing strings and resolves those graphemes. The only thing you should pay attention to is the encoding (that answer is based upon UTF8, by it can be easily switched to any other): https://stackoverflow.com/a/32903103/2799410
i'm saving a NSString inside an NSArray and that NSArray inside an NSDictionary. While doing this, a process inside my NSDictionary notifies me if my string is like Hi I'm XYZ. Then in the place of single quote the appropriate UTF character is getting stored.
So how to avoid this or how can I get my actual text along with special characters from NSArray or from my NSDictionary?
Any help is thankful.
NSString internally uses Unicode characters. So it easily can handle all sorts of characters from different languages.
You cannot choose the internal encodig of NSString. It's always Unicode. If you have an encoding problem, then you have either created the NSString instance incorrectly or you have output the instance the wrong way.
And there's no such thing as an UTF character.
Please better describe your problem and show the relevant source code.
I have some xml that is coming back from a web service. I in turn use xslt to turn that xml into json (I am turning someone else's xml service into a json-based service). My service, which is now outputting JSON, is consumed by my iphone app using the de facto iphone json framework, SBJSON.
The problem is, using the [string JSONValue] method chokes, and I can see that it's due to line breaks. Lo and behold, even the FAQ tells me the problem but I don't know how to fix it.
The parser fails to parse string X
Are you sure it's legal JSON? This framework is really strict, so won't accept stuff that (apparently) several validators accepts. In particular, literal TAB, NEWLINE or CARRIAGE RETURN (and all other control characters) characters in string tokens are disallowed, but can be very difficult to spot. (These characters are allowed between tokens, of course.)
If you get something like the below (the number may vary) then one of your strings has disallowed Unicode control characters in it.
NSLocalizedDescription = "Unescaped control character '0x9'";
I have tried using a line such as: NSString *myString = [myString stringByReplacingOccurrencesOfString:#"\n" withString:#"\\n"];
But that doesn't work. My xml service is not coming back as CDATA. The xml does have a line break in it as far as I can tell (how would I confirm this). I just want to faithfully transmit the line break into JSON.
I have actually spent an entire day on this, so it's time to ask. I have no pride anymore.
Thanks alot
Escaping a new line character should work. So following line should ideally work. Just check if your input also contains '\r' character.
NSString *myString = [myString stringByReplacingOccurrencesOfString:#"\n" withString:#"\\n"];
You can check which control character is present in the string using any editor which supports displaying all characters (non-displayable characters as well). e.g. using Notepad++ you can view all characters contained in a string.
It sounds like your XSLT is not working, in that it is not producing legal JSON. This is unsurprising, as producing correctly formatted JSON strings is not entirely trivial. I'm wondering if it would be simpler to just use the standard XML library to parse the XML into data structures that your app can consume.
I don't have a solution for you, but I usually use CJSONSerializer and CJSONDeserializer from the TouchJSON project and it is pretty reliable, I have never had a problem with line breaks before. Just a thought.
http://code.google.com/p/touchcode/source/browse/TouchJSON/Source/JSON/CJSONDeserializer.m?r=6294fcb084a8f174e243a68ccfb7e2c519def219
http://code.google.com/p/touchcode/source/browse/TouchJSON/Source/JSON/CJSONSerializer.m?r=3f52118ae2ff60cc34e31dd36d92610c9dd6c306
I am getting problem while parsing xml files that contains some special characters like single quote,double quote (', "")etc.I am using NSXMLParser's parser:foundCharacters:method to collect characters in my code.
<synctext type = "word" >They raced to the park Arthur pointed to a sign "Whats that say" he asked Zoo said DW Easy as pie</synctext>
When i parse and save the text from above tag of my xml file,the resultant string is appearing,in GDB, as
"\n\t\tThey raced to the park Arthur pointed to a sign \"Whats that say\" he asked Zoo said DW Easy as pie";
Observe there are 2 issues:
1)Unwanted characters at the beginning of the string.
2)The double quotes around Whats that say.
Can any one please help me how to get rid of these unwanted characters and how to read special characters properly.
NSString*string =[string stringByTrimmingCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:#" \n\t"]];
The parser is apparently returning exactly what's in the string. That is, the XML was coded with the starting tag on one line, a newline, two tabs, and the start of the string. And quotes in the string are obviously there in the original (and it's not clear in at least this example why you'd want to delete them).
But if you want these characters gone then you need to post-process the string. You can use Rams' statement to eliminate the newline and tabs, and stringByReplacingOccurrencesOfString:WithString: to zap the quotes.
(Note that some XML parsers can be instructed to return strings like this with the leading/trailing stuff stripped, but I'm not sure about this one. The quotes will always be there, though.)
Does anyone know of an easy way to add a single backslash (\) to a NSString in Objective-C? I am trying to have a NSString *temp = #"\/Date(100034234)\/";
I am able to get a double backslash or no backslash, but unable to get a single backslash. Any help would be appreciated. Thanks
The string #"\\" is a single backslash, #"\\\\" is a double backslash
The strings and NSLog are working fine for me (iPhone SDK 3.1.2 and Xcode 3.2.1):
NSLog(#"\\"); // output is one backslash
NSLog(#"\\\\"); // output is two backslashes
NSLog(#"\\/Date(100034234)\\/"); // output is \/Date(100034234)\/
See this answer.
This is a bug in NSLog. I found a mailing list archive with a message dated in 2002 of someone that filed a bug for this here. The person also said this:
Nothing has been done as far as I can tell. I don't understand how
they've done it, but the escaping does work for the string, just not for
NSLog.
So I guess you will have to come up with your own implementation of a log message if you really want backslashes.
This code does give the requested output:
NSString *temp = #"\\/Date(100034234)\\/";
NSLog(#"%#",temp);
However I had an issue with my JSON toolkit (SBJSON) that replaced all occurrances of "\\" with "\\\\", which did cause issues as described in the other answers and the comments.
The result was a string looking like:
#"\\\\/Date(100034234)\\\\/"
See my answer here
The solution was using:
temp = [temp stringByReplacingOccurancesOfString:#"\\\\" withString:#"\\"];
Where you want a \ add or remove. just \\ on that place.