I'm using [NSData dataWithContentsOfURL:] to create two NSData instances and I want to compare these instances to gauge how different they are. Since they're both from the same website, using a string to find what is different will help me highlight the actual element(s) that has (have) changed. Is it possible to change this data to a string to find the difference?
Try initWithData:encoding: method of NSString to create string with your data.
Exmp: NSString *str = [[NSString alloc] initWithData:someData encoding:NSUTF8StringEncoding]
Why don't you use NSString
stringWithContentsOfURL:encoding:error:
Related
I am trying to identify between three types of objects:
if it is a URL of a file
If it is a URL of a directory
if it is a simple string
up till now, I have just this code, which does not work!
NSArray * classes = nil;
classes = [[NSArray alloc] initWithObjects:[NSURL class],
[NSAttributedString class],[NSString class], nil];
NSDictionary *options = [NSDictionary dictionary];
NSArray * copiedItems = nil;
copiedItems = [pb readObjectsForClasses:classes options:options];
Now I try to take the first object of the array copiedItems and try to call "types" property and i get a crash!
Check here and here:
You would need to use these pasteboard types, instead of the ones you're using.
NSString *NSStringPboardType;
NSString *NSFilenamesPboardType;
NSString *NSPostScriptPboardType;
NSString *NSTIFFPboardType;
NSString *NSRTFPboardType;
NSString *NSTabularTextPboardType;
NSString *NSFontPboardType;
NSString *NSRulerPboardType;
NSString *NSFileContentsPboardType;
NSString *NSColorPboardType;
NSString *NSRTFDPboardType;
NSString *NSHTMLPboardType;
NSString *NSPICTPboardType;
NSString *NSURLPboardType;
NSString *NSPDFPboardType;
NSString *NSVCardPboardType;
NSString *NSFilesPromisePboardType;
NSString *NSMultipleTextSelectionPboardType;
There's an pasteboard type for URLs. To distinguish between a file and a folder, you would need to instantiate an NSURL object with the pasteboard data, and find out if it is a directory by querying its attributes.
EDIT:
You also need to consider if the pasteboard data is being put there by your own application or other applications. If it's being put by other applications, I'm not sure the pasteboard types with the classes will work.
I use something like this in one of my projects:
supportedTypes = // array with supported types, maybe from the list
NSString *type = [pasteboard availableTypeFromArray:supportedTypes];
NSData *data = [pasteboard dataForType:type];
types is a method on NSPasteboard used to tell you what is available from the pasteboard. So, you shouldn't call it on the items you get back from the pasteboard.
If you're going to request multiple class types, iterate over the response and check the class type of each item, then decide how to interact with it.
Alternatively, decide which class type of data is most useful and make individual class type requests to the pasteboard. If you get a result back, use it and carry on, if not, try the next most useful class type. Look at using canReadObjectForClasses:options: to make this easier.
I need to create a JsonString from a NSString, without any key in ObjC.
All tutorials talks about serialization from NSDictionary or NSData.
My string is like #"fr-FR".
The result i'm looking for is like #"{"fr-FR"}", but dynamically.
Can't do it myself because i will need to do the same stuff for different kind of arguments.
Thanks in advance :)
To achieve the result you are asking for (even if it's not a proper JSON) you could try something like this:
NSString *myString = #"fr-FR"; // Or whatever
NSString *result = [NSString stringWithFormat:#"{\"%#\"}", myString];
You need to use a JSON framework/library, for example TouchJSON, and then you can do the following to encode your NSString:
theData = [[CJSONSerializer serializer] serializeObject:theString
error:&theError];
(from the demo code here).
You could use NSJSONSerialization class if you develop on IOS 5 +
create data with your string
NSString *myString = #"fr-FR"; // Or whatever
NSString *result = [NSString stringWithFormat:#"{%#}", myString];
NSData* data=[result dataUsingEncoding:NSUTF8StringEncoding];
and then use
+ (id)JSONObjectWithData:(NSData *)data options:(NSJSONReadingOptions)opt error:(NSError **)error
to create your JSON object
(just typed, not tested)
IMHO after reading the json spec again ( http://www.json.org ) {"string"} isn't valid json and the code you are using in c# produces invalid results. However, if you need to communicate with c# code that acts this way you should just encode the string itself using a JSON library and then afterwards pack it in curly braces. That way you get all the escaping needed for JSON for special cases (e.g. quotes and whatnot) which you don't if you just add quotes and braces manually.
I am trying to store user input text (in this case a book title) into an array so that I can output it in a table view in another xib.
I'm getting stuck trying to store the "bookTitle.text" info into my "userinfoArray". I know it probably has a simple solution and I know how to do it in C++ but not in Objective-C. Any tips, links etc. would be great.
NSMutableArray *userinfoArray = [[NSMutableArray alloc]init];
NSString *tempString = [[NSString alloc]initWithString:[bookTitle text]];
[userinfoArray addObject:tempString];
you can then access it later with:
[userinfoArray objectAtIndex:0];
NSMutableArray is very flexible. with addObject:object you can add as many things as you want, remove them with removeObjectAtIndex:index.
more here: NSMutableArray Class Reference
alternatively if you know what size your array will have you can use a normal NSArray: NSArray Class Reference which will work similar
sebastian
Try
userinfoArray = [NSArray arrayWithObject:[bookTitle text]];
Or if you want to create a longer array with more objetcs then
userinfoArray = [NSArray arrayWithObjects:[bookTitle text], secondObject, thirdObject, nil];
If you want to add or remove objects later then you may want to use NSMutableArray instead.
If this does not answer your question, then please try to be a bit more specific about your problem.
If I have a NSString that came back from a web service in the form of a plist structure, how can I initialize a NSMutableArray with this NSString. I want to know if there is a similar way to initWithContentsOfFile for NSString.
My first thought was to save the NSString to a file and then use initWithContentsOfFile; but I am trying to avoid save to file first. It seems like there should be a simpler way.
Untested, should work like this:
NSData *data = [myString dataUsingEncoding:NSUTF8StringEncoding];
NSMuableArray *array = [NSPropertyListSerialization
propertyListWithData:data
options:NSPropertyListMutableContainers
format:NSPropertyListXMLFormat_v1_0
error:NULL];
See the Property List Programming Guide "Reading and Writing Property-List Data". It covers how to turn NSData into a property list. If you already have NSData from the network, just don't convert it to NSString. If you only have an NSString, use dataUsingEncoding: to convert it to NSData.
Check the documentation for the -propertyList and -mutableCopy methods.
You could use NSXMLParser to parse the XML (which is what a plist is) and turn it into a dictionary (and retrieve the array from there)
I'm working on writing to a file one user input on a textField.
So far I have one NSFileManager which writes data to a file. Still, I have no way of putting the textField input inside a file.
Is there a way do add a string value to NSData so I can write it?
you can get NSData from NSString,
NSData *newData = [yourString dataUsingEncoding:NSUTF16StringEncoding];
use encoding that fits your case.
append the obtained data to existing NSData,
[existingData appendData:newData]
Note: "existingData" should be an instance of NSMutableData.
Use below code as your reference.
NSString* myString = #"Is there a method for adding one NSString for NSData";
NSData* myData= [myString dataUsingEncoding:NSUTF8StringEncoding];