Weird value from NSDictionary - iphone

I got a NSDictionary that when I do a [currentOrder debugDescription] call on it the layout is below, when I then do a:
[currentOrder valueForKey: #"itemOrder"]
It return it funny with the brackets as:
(
"4 X ESPRESSO"
)
where it should only be (without brackets):
4 X EXPRESSO
Any idea why?
Content of currentOrder:
currentOrder: <__NSArrayM 0x68426c0>(
{
extra1Select = 0;
extra2Select = 0;
extra3Select = 0;
itemCost = 58;
itemOrder = "4 X ESPRESSO";
itemOrderDescription = "Cookie: YES, Sugar: YES";
itemQuantity = 4;
itemRestaurant = VidaECaffe;
plistItem = {
cost = "11.5";
description = "R11.50";
extra1 = {
desc = Cookie;
details = (
{
cost = "3.00";
option1 = YES;
},
{
cost = "0.00";
option2 = NO;
}
);
};
extra2 = {
desc = Sugar;
details = (
{
cost = "0.00";
option1 = YES;
},
{
cost = "0.00";
option2 = NO;
}
);
};
itemRestaurant = VidaECaffe;
level = 1;
title = ESPRESSO;
};
}
)

The problem is that currentOrder is not a dictionary but a NSArray containing a dictionary. The failure you are making next is that you use valueForKey: which is part of the key value coding family and not the designated access method for dictionaries (which is objectForKey:), and the array returns you a filtered array as a result...

When you print out the value of an array or dictionary in the debugger, the debugger includes the extra brackets, braces, and whatnot so you can see the layout of the structure you are asking about.
If the debugger shows the contents of an array something like
(
"Foobar"
)
it's telling you that the array has one element, a string with the value Foobar.
Put entirely another way: Read up on what the debugger does when it prints out values. Lots of resources here and on the web for this. For example: Debugging with GDB: Introduction to Commands, Print and Print-Object

Related

How to identify the type of an object?

Here is my JSON response for a particular API.
Case 1
ChallengeConfiguration = {
AnswerAttemptsAllowed = 0;
ApplicantChallengeId = 872934636;
ApplicantId = 30320480;
CorrectAnswersNeeded = 0;
MultiChoiceQuestion = (
{
FullQuestionText = "From the following list, select one of your current or previous employers.";
QuestionId = 35666244;
SequenceNumber = 1;
},
{
FullQuestionText = "What color is/was your 2010 Pontiac Grand Prix?";
QuestionId = 35666246;
SequenceNumber = 2;
}
)
}
The key "MultiChoiceQuestion" returns an array with two questions. So here is my code.
let QuestionArray:NSArray = dict1.objectForKey("ChallengeConfiguration")?.objectForKey("MultiChoiceQuestion") as! NSArray
Case 2
ChallengeConfiguration =
{
AnswerAttemptsAllowed = 0;
ApplicantChallengeId = 872934636;
ApplicantId = 30320480;
CorrectAnswersNeeded = 0;
MultiChoiceQuestion = {
FullQuestionText = "From the following list, select one of your
current or previous employers.";
QuestionId = 35666244;
SequenceNumber = 1;
}
}
For Case 2 my code does not work and app crashes because it returns a dictionary for that specific Key. So how could I write a generic code that would work for all objects?
It looks like the key can contain either an array of dictionary values or a dictionary, so you just need to try casting to see which one you have.
so I would likely do it like this:
if let arr = dict1.objectForKey("ChallengeConfiguration")?.objectForKey("MultiChoiceQuestion") as? Array {
// parse multiple items as an array
} else if let arr = dict1.objectForKey("ChallengeConfiguration")?.objectForKey("MultiChoiceQuestion") as? [String:AnyObject] {
// parse single item from dictionary
}
You should never really use ! to force unwrap something unless you are completely certain that the value exists and is of the type you are expecting.
Use conditional logic here to test the response and parse it safely so that your app doesn't crash, even in failure.

Swift, dictionary parse error

I'm using an API to get weather condition and the retrieved dict is
dict = {
base = stations;
clouds = {
all = 92;
};
cod = 200;
coord = {
lat = "31.23";
lon = "121.47";
};
dt = 1476853699;
id = 1796231;
main = {
"grnd_level" = "1028.63";
humidity = 93;
pressure = "1028.63";
"sea_level" = "1029.5";
temp = "73.38";
"temp_max" = "73.38";
"temp_min" = "73.38";
};
name = "Shanghai Shi";
rain = {
3h = "0.665";
};
sys = {
country = CN;
message = "0.0125";
sunrise = 1476827992;
sunset = 1476868662;
};
weather = (
{
description = "light rain";
icon = 10d;
id = 500;
main = Rain;
}
);
wind = {
deg = "84.50239999999999";
speed = "5.97";
};
}
If I want the value of humidity, I just use
let humidityValue = dict["main"]["humidity"] and it works.
But the problem is I also want to get the value of description in weather
when I used let dscptValue = dict["weather"]["description"]
it retrieved nil.
How's that? and I notice there are two brackets around weather .I'm not sure whether it is the same with the statement without brackets.
weather = (
{
description = "light rain";
icon = 10d;
id = 500;
main = Rain;
}
);
How to get the value of description?
weather keys contains Array of Dictionary not directly Dictionary, so you need to access the first object of it.
if let weather = dict["weather"] as? [[String: AnyObject]], let weatherDict = weather.first {
let dscptValue = weatherDict["description"]
}
Note: I have used optional wrapping with if let for preventing crash with forced wrapping.
Weather is an array of dictionaries.
dict["weather"][0]["description"]
may give you the expected result.

Multidimensional array makes Xcode6 crash

I have an application which retrieves a JSON file. Here you are a piece of my code:
Array definition
var photos: NSArray = []
How I populate the array:
ezJson().createRequest("http://myapiurl/load", type: "GET", params: nil, completion: {(returnedObject : AnyObject?, error : NSError?)in
if returnedObject{
self.photos = returnedObject as NSArray
self.tableView.reloadData()
}
})
println(self.photos)
{
created = {
date = "2014-06-13 18:35:46";
timezone = "Europe/Madrid";
"timezone_type" = 3;
};
description = description1;
id = 3;
name = 539b286277617;
},
{
created = {
date = "2014-06-13 18:38:38";
timezone = "Europe/Madrid";
"timezone_type" = 3;
};
description = description2;
id = 4;
name = 539b290ed8577;
}
println(self.photos[0])
{
created = {
date = "2014-06-13 18:35:46";
timezone = "Europe/Madrid";
"timezone_type" = 3;
};
description = description1;
id = 3;
name = 539b286277617;
}
The problem is, I don't know how to get a particular item. I've tried:
println(self.photos[0]) // it works
println(self.photos[0]["name"] // Xcode crash "Command /Applications/Xcode6-Beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift failed with exit code 254"
println(self.photos[0].name) // returns nil
How can I access to the name parameter ?
It seems that you are casting a String to NSArray. This won't give you the effect that you want.
First of all, if you want to acces your elements by name, you want an NSDictionary.
Then it propably still won't work, as there is no implicit conversion between the types so you will have to either parse it yourself or use some JSON library.
Last : your JSON is incorrect.

How to access a certain value in an NSArray?

I have an array called someArray. I would like to access the name value of the NSArray. I'm trying to access it using the following, but with out any luck. How do I do it properly?
cell.textLabel.text = [[someArray objectAtIndex:indexPath.row] objectForKey:#"name"];
some array {
haserror = 0;
headers = {
code = 0;
haserror = 0;
nodeid = "fe1.aaaaaa.2.undefined";
time = 16;
};
results = (
{
coords = (
"44.916667",
"8.616667"
);
id = 2;
key = alessandria;
name = Alessandria;
state = Piemonte;
zip = 1512;
},
{
coords = (
"43.616944",
"13.516667"
);
id = 3;
key = ancona;
name = Ancona;
state = Marche;
zip = 601;
},
}
As far as i see from you data model, the key name is a node under the key results. You can use this data model as a dictionary map, the code snippet below must give you what you need..
NSDictionary *myObject = [[someArray objectAtIndex:indexPath.row] objectForKey:#"results"];
cell.textLabel.text = [myObject objectForKey:"name"];
IMPORTANT NOTE: If you have some lopps or some other mechanisms for receiving data, there may be more efficent ways for your sıolution, so please give some more additional info about what you are exactly tryin to do
As others have noted, someArray is a dictionary while results is a key pointing to an array inside of your dictionary. If you want an array of all of the name fields in your results array, you could use valueForKeyPath: on the someArray variable, like this:
NSArray *names = [someArray valueForKeyPath:#"results.name"];
The names variable should now contain "Alessandria", and "Ancona" from the data set your show in your example code.

Not sure of the value being retrieved from NSDictionary

I want to retrive a value from a NSDictionary.
Here is a snippet of code:
NSDictionary *metadataDict = [representation metadata];
NSLog(#"%#",metadataDict);
"DateTimeOriginal" is the value I want to retrieve from the following output.
{
ColorModel = RGB;
DPIHeight = 72;
DPIWidth = 72;
Depth = 8;
Orientation = 6;
PixelHeight = 1936;
PixelWidth = 2592;
"{Exif}" = {
ApertureValue = "2.970854";
ColorSpace = 1;
ComponentsConfiguration = (
1,
2,
3,
0
);
DateTimeDigitized = "2011:09:28 09:35:36";
DateTimeOriginal = "2011:09:28 09:35:36";
ExifVersion = (
2,
2,
1
);
ExposureMode = 0;
ExposureProgram = 2;
ExposureTime = "0.06666667";
FNumber = "2.8";
Flash = 24;
FlashPixVersion = (
1,
0
);
FocalLength = "3.85";
ISOSpeedRatings = (
320
);
MeteringMode = 5;
PixelXDimension = 2592;
PixelYDimension = 1936;
SceneCaptureType = 0;
SensingMethod = 2;
Sharpness = 2;
ShutterSpeedValue = "3.9112";
SubjectArea = (
1295,
967,
699,
696
);
WhiteBalance = 0;
};
"{GPS}" = {
Latitude = "37.54216666666667";
LatitudeRef = N;
Longitude = "126.95";
LongitudeRef = E;
TimeStamp = "01:19:05.00";
};
"{TIFF}" = {
DateTime = "2011:09:28 09:35:36";
Make = Apple;
Model = "iPhone 4";
Orientation = 6;
ResolutionUnit = 2;
Software = "4.3.5";
XResolution = 72;
YResolution = 72;
"_YCbCrPositioning" = 1;
};
}
I know it's long but I tried these three and it still would not work.
NSLog(#"valueForKey %#", [metadataDict valueForKey:#"DateTimeOriginal"]);
NSLog(#"valueForKeyPath %#", [metadataDict valueForKeyPath:#"DateTimeOriginal"]);
NSLog(#"objectForKey %#", [metadataDict objectForKey:#"DateTimeOriginal"]);
Does anyone know what kind of datatype is in the NSDictionary and how I can retrieve it?
Thanks much.
Above project link:
http://dl.dropbox.com/u/12439052/TheK2.zip
What you're really looking for is
NSDictionary *exif = [metadataDict objectForKey:#"{Exif}"];
NSLog(#"DateTimeOriginal: %#", [exif objectForKey:#"DateTimeOriginal"]);
If you read the output from your first log, you'll see that the key you want is actually inside another dictionary which has the key "{Exif}". Also, -objectForKey: is the better method here to use rather than -valueForKey: (the latter is for generic KVO, the former is the real dictionary object accessor).
Try this one:
NSString *DateTimeOriginal=[[metadataDict objectForKey:#"{Exif}"]objectForKey:#"DateTimeOriginal"];
During Response Value of lines keep in mind
{ .......... } indicates dictionary.
(............) indicates array.
Dictionary always have key with it like somename = "value in it".
Array has value seperated by comma like a , b , c .....
Now it is possible it may have array into dictionary like { SubjectArea = ( 1295,967,699,696);} and vice versa.