I'm a noob when it comes to requests and JSON. Inside my app I send to the server and get back stuff so I can use it of course. I tried looking up different things but none really seem to be what I'm looking for. So I'm getting back what seems to be formatted JSON. What I want to know how to do is put it into a NSMutable array. The way I get this JSON is by using AFNetworking's AFJSONRequestOperation.
My response looks like this.
{
id = 38;
name = "St. Martin Hall";
},
{
id = 40;
name = "Assumptions Commons";
},
{
id = 41;
name = "Vickroy Hall";
},
{
id = 42;
name = "St. Ann Hall";
},
{
id = 37;
name = "Duquesne Towers";
}
if your JSON format like {"mainKey":[{},{},...]}
NSError* error;
NSDictionary* json = [NSJSONSerialization
JSONObjectWithData:responseData //1
options:kNilOptions
error:&error];
NSArray* dataArray = [json objectForKey:#"mainKey"]; //2
else your JSON format like [{},{},...]
NSError* error;
NSArray* dataArray = [NSJSONSerialization
JSONObjectWithData:responseData //1
options:kNilOptions
error:&error];
I think your format is case 2: [] Array of Object {}
Tutorial: http://www.raywenderlich.com/5492/working-with-json-in-ios-5
JSON:http://www.json.org
You use the NSJSONSerialization class to convert JSON to Foundation objects and convert Foundation objects to JSON.
This class is available in iOS 5.0+. If you're targetting older iOS version, have a look at a third-party JSON framework:
Comparison of JSON Parser for Objective-C (JSON Framework, YAJL, TouchJSON, etc)
If that's what you're getting back it's not JSON I'm afraid. It does look like Javascript in a way but it should be more like
[
{
"id" : 38,
"name" : "St. Martin Hall"
},
{
"id" : 39,
"name" : "Assumptions Commons"
}
]
Related
I get the JSON format like this:
stream( { posts: [{CHANNEL: {ios: "(format=m3u8-aapl).m3u8"} }]})
What I want to get is an array for the "ios".
This is my code:
id jsonObjects = [NSJSONSerialization JSONObjectWithData:
jsonSource options:NSJSONReadingMutableContainers error:nil];
for (NSDictionary *dataDict in jsonObjects) {
NSArray *ios_data = [[[dataDict objectForKey:#"posts"] objectForKey:#"CHANNEL"] objectForKey:#"ios"];
NSLog(#"%#",ios_data);
dict = [NSDictionary dictionaryWithObjectsAndKeys:ios_data, ios,nil];
}
but it return in NULL, what the problem of it?
Your "JSON":
stream( { posts: [{CHANNEL: {ios: "(format=m3u8-aapl).m3u8"} }]})
Is not JSON. You can try running it through a validator like http://jsonlint.com/ to test it out.
Also, you should create an NSError reference to pass in instead of nil so NSJSONSerialization can vend you an error object. This will help in your debugging.
Here is an example of what your data would look like if it were valid JSON:
{
"stream": [
{
"posts": [
{
"CHANNEL": {
"ios": "(format=m3u8-aapl).m3u8"
}
}
]
}
]
}
(I spaced it out to be more legible, but the spacing is unnecessary for parsing.)
Once you have your array holding 'posts' you can drill down like this:
NSArray *fileData = [myDic1 valueForKeyPath:#"posts.CHANNEL"];
and then access like this:
for (int i=0; i < [clientFileData count]; i++) {
NSDictionary *myDictionary = [fileData objectAtIndex:i];
]
Also, unless I am wrong, your JSON file seems incorrectly formatted.
Get your response like:
NSDictionary *dictionaryData = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&error];
Correct JSOn should be like this
{
"posts":[
{
"CHANNEL":{
"ios":"(format=m3u8-aapl).m3u8"
}
}
]
}
Get the correct format of JSON and then try to parse it. And one thing you were doing wrong is POST is an array.
I have a JSON array(dictionary?) of objects that are themselves an array. I need to find a value within one of these arrays so that I can compare it later. Part of my JSON data:
[
{
"Name": "Exhibitor",
"Url": "api/congress/exhibitor",
"ResourceType": "Data",
"LastMod": 1389106977
},
{
"Name": "Workshop",
"Url": "api/congress/workshop",
"ResourceType": "Data",
"LastMod": 1389106977
},
{
"Name": "Speaker",
"Url": "api/congress/Speaker",
"ResourceType": "Data",
"LastMod": 1389106977
},
]
My method receives a table name as a parameter and returns a time stamp. How would I receive the time stamp (1389106977) for the table "workshop" for example? This seems so simple but I cannot work it out for 'nested' arrays/dictionaries.
Thanks,
edit:
This is the my code with trojanfoe's added to it.
NSError* localError;
NSMutableArray *syncDataArray = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error];
if (syncDataArray)
{
NSNumber *lastMod = nil;
for (NSDictionary *dict in syncDataArray)
{
NSLog(#"current table is: %#", dict[#"Name"]);
if ([tableName isEqualToString:dict[#"Name"]])
{
lastMod = dict[#"LastMod"];
//break;
}
}
NSLog(#"LastMod = %#", lastMod);
}
else
{
NSLog(#"syncDataArray is empty");
}
This works perfectly and makes sense
The JSON data looks like an array of dictionaries, so you can iterate over the array and test for the "Name" entry:
NSArray *jsonData = ...; // You have converted JSON to Objective-C objects already
NSNumber *lastMod = nul;
for (NSDictionary *dict in jsonData) {
if ([#"Workshop" isEqualToString:dict[#"Name"]]) {
lastMod = dict[#"LastMod"];
break;
}
}
if (lastMod) {
// You found it
}
(Note I am not certain the type of object used to store the "LastMod" object, so you might need to do some debugging to find out).
EDIT If you make extensive use of this data you should immediately convert the JSON data into an array of (custom) model objects, which will make it easier to manipulate the data as your app becomes more complex.
You have an array for dictionaries so it would look something like :
NSNumber *timestamp = [[JSON objectAtIndex:index] objectForKey:#"LastMod"];
NSNumber *timestamp = response[1][#"LastMod"];
Is there any way to get JSON object from the server in the same order??
For example when i fitch using browser my JSON object return like this:
{
"23": {
"numberOfRecords": "3",
"startDate": "27/11/2013",
"endDate": "31/12/2014",
"question": "How do you rate the new MenaME Portal ?",
"voteScale": "5",
"questions": {
"option1": {
"value": "1",
"option": "Poor",
"voteResult": "50.000"
},
"option2": {
"value": "2",
"option": "Acceptable",
"voteResult": "0.000"
},
"option3": {
"value": "3",
"option": "Good",
"voteResult": "0.000"
},
"option4": {
"value": "4",
"option": "Very Good",
"voteResult": "0.000"
},
"option5": {
"value": "5",
"option": "Excellent",
"voteResult": "50.000"
}
},
"selectedAnswer": "0",
"voteAnswered": "0",
"votes": "6"
}
}
after parsing it with [NSJSONSerialization JSONObjectWithData:jsonData options:kNilOptions error:&error]
the object returned like this :
{
23 = {
endDate = "31/12/2014";
numberOfRecords = 3;
question = "How do you rate the new MenaME Portal ?";
questions = {
option1 = {
option = Poor;
value = 1;
voteResult = "50.000";
};
option2 = {
option = Acceptable;
value = 2;
voteResult = "0.000";
};
option3 = {
option = Good;
value = 3;
voteResult = "0.000";
};
option4 = {
option = "Very Good";
value = 4;
voteResult = "0.000";
};
option5 = {
option = Excellent;
value = 5;
voteResult = "50.000";
};
};
selectedAnswer = 0;
startDate = "27/11/2013";
voteAnswered = 0;
voteScale = 5;
votes = 6;
};
}
Is there any way or framework to get the object as it (in the same order returned from the server) ??
Dictionaries, both in JSON and NSDictionary, are unordered, meaning that it is irrelevant which order you see things in the log. This is defined in the JSON specification and the documentation for NSDictionary.
If it actually matters what order things are displayed in, then either the API you are linking to isn't using correct JSON, or you're doing something wrong in your app. To help with those situations you can use several of the sorted NSDictionary implementations that are around.
Can I ask why you want to ensure the dictionary is maintained in the correct order?
I understand in some cases (mine) an ancient JSON -> XML web service was being called by my app and the client refused to adjust the service so it could accept unordered JSON (valid json) but if you're writing the app, why do you need to ensure that it is in order?
I have a NSMutableDictionary subclass that keeps objects added by setObject:forKey in the order you call the method that can be found here.
It works by storing a NSMutableOrderedSet of keys within the dictionary and then overrides the keyEnumerator method to return an enumerator based on the ordered set
- (NSEnumerator *)keyEnumerator
{
return [self.orderedSetOfKeys objectEnumerator];
}
You could modify the NSMutableDictionary subclass i created to expose the NSMutableOrderedSet in the public header and then modify this set yourself to get an ordered version of your dictionary.. For example:
NSDictionary *JSONWebServiceDictionary = [NSJSONSerialization JSONObjectWithData:jsonData options:kNilOptions error:&error];
LNOrderedMutableDictionary *orderedDictionary = [[LNOrderedMutableDictionary alloc] initWithDictionary:JSONWebServiceDictionary];
NSMutableOrderedSet *order = [[NSMutableOrderedSet alloc] initWithArray:#[#"key1",#"key2",#"key3"]]; //All the keys you are expecting and the order you want them in..
orderedDictionary.orderSet = order; //orderSet does not exist.. it is currently called `array` and not exposed in LNOrderedMutableDictionary.h
I haven't tested the code above but unless you want to create or modify an existing JSON parser then it seems that it is your only option..
If you did want to modify an existing parser then it might just be as simple as replacing dictionary instances with LNOrderedMutableDictionary to keep everything in order.
Another idea to expand the above sample code could be to replace
NSMutableOrderedSet *order = [[NSMutableOrderedSet alloc] initWithArray:#[#"key1",#"key2",#"key3"]];
with an array returned in the JSONWebServiceDictionary dictionary as arrays keep their order when parsed from JSON so maybe you could do this?
NSMutableOrderedSet *order = [[NSMutableOrderedSet alloc] initWithArray:[JSONWebServiceDictionary objectForKey:#"keyOrderArray"]]];
Look at what you have. If you test the result you got back from JSONObjectWithData (which we'll assume was declared as id jsonObject)
if ([jsonObject isKindOfClass:[NSDictionary class]) { ...
or
NSLog(#"The object type is %#", [jsonObject class]);
you will find that it is indeed an NSDictionary (or perhaps an NSMutableDictionary). That dictionary, as you can see from the dump (or infer from the nearly identical JSON) contains a single entry with a key of "23".
So let's cast the jsonObject to an NSDictionary and reference it:
NSDictionary* jsonDict = (NSDictionary*) jsonObject;
NSDictionary* entry23Dict = [jsonDict objectForKey:#"23"];
Now, if you NSLog entry23Dict you will discover it contains all of the above, absent the { 23 = ... } outermost dictionary.
You can then access, say, "questions" with
NSDictionary* questDict = [entry23Dict objectForKey:#"questions"];
From there the individual "option1", "option2", ... "option5" dictionaries can be accessed in a similar fashion. You simply proceed one layer at a time -- don't get overwhelmed by the entire structure. (It's often helpful, when you're first learning, to NSLog each "layer" as you "peel" it out of the containing structure.)
And, of course, you have all the standard facilities that are available to NSDictionary objects (and NSArray objects, should your JSON contain any [..] arrays). For instance, you can iterate on the keys of the dictionary with
for (NSString* key in jsonDict) {
NSLog(#"This entry's number is %#", key); // For the above will print "23"
NSDictionary* numberedDict = jsonDict[key]; // Using the "new" form of dictionary access
NSString* endDate = numberedDict[#"endDate"]; // Ditto
NSLog(#"The end date is %#", endDate);
}
This is a fairly common problem. It's also probably the most annoying part about iOS. (java doesn't have this issue at all). If you want to get back objects, take a look at restkit.org Specifically this answer may help: https://stackoverflow.com/a/8284343/836450
I make a request to the Instapaper API, and it's supposed to return JSON. It returns something close to JSON, but not completely, like follows:
2013-05-30 19:54:20.155 --[53078:c07] (
{
type = meta;
},
{
"subscription_is_active" = 1;
type = user;
"user_id" = --;
username = "--#gmail.com";
},
{
"bookmark_id" = 387838931;
description = "";
hash = YHwQuwhW;
"private_source" = "";
progress = 0;
"progress_timestamp" = 0;
starred = 0;
time = 1369954406;
title = "Adobe Finally Releases Kuler Color-Picking App for iPhone - Mac Rumors";
type = bookmark;
url = "http://www.macrumors.com/2013/05/30/adobe-finally-releases-kuler-color-picking-app-for-iphone/";
},
How do I then process this? Can I take it and turn it into an NSDictionary even though it doesn't seem to be valid JSON?
From Instapaper API Docs:
Instapaper strings are always encoded in UTF-8, and Instapaper expects all input to be in UTF-8.
Unless otherwise noted, output from every method is an array. The output array is returned as JSON by default.
You can specify a jsonp parameter with a callback function name, e.g. jsonp=myCallback, to use JSONP and wrap the output in a call to the specified function.
So there is no way you will get not valid JSON!
Try following code:
NSData *jsonData = [[NSString stringWithContentsOfURL:[NSURL urlWithString:#"http://your-instapeper-API-link"] encoding:NSUTF8StringEncoding error:nil] dataUsingEncoding:NSUTF8StringEncoding];
NSError *error;
id serializationJSON = [NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONReadingMutableContainers error:&error];
And then you can log what is wrong or if result is what you expect:
NSLog(#"class of JSON input: %# \n and possible error: %#",[serializationJSON class],error);
Of course you should expect Array and no error.
EDIT ... based on coment code:
Based on docs you should get Array or Dictionary. Please add this core instead your line #23 (numer from here):
if([JSON isKindOfClass:[NSDictionary class]]) {
NSDictionary *jsonDictionary = JSON;
NSLog(#"%#",[jsonDictionary allKeys]);
} else {
NSLog(#"JSON object class: %#",[JSON class]);
}
and please show us output.
One more thing:
You get array from request. Great! This is a valid JSON. So you need to debug it. As i said it's a shame is not a unlimited acccess public API, so i can look into it. But now you have to debug your result. I see in your code that you are trying to access bookmarks. So i look into Bookmarks section in docs and this is some kind of list (NSArray). So if you don't know what result you want. You should print them into log (or set a breakpoint). Replace code from my earlier update with this simple log:
NSDictionary *resultDictionary;
if([JSON isKindOfClass:[NSArray class]]) {
NSArray *jsonArray = JSON;
NSLog(#"so json is an array with %i objects",[jsonArray count]);
for(id objectInsideArr in jsonArray) {
NSLog(#"object in array [class]: %# [value]: %#",[objectInsideArr class],objectInsideArr); //if here you find NSDictionary maybe is this dictionary you are looking for. I'm not sure what it is.
if([objectInsideArr isKindOfClass:[NSDictionary class]]) {
resultDictionary = [[NSDictionary alloc] initWithDictionary:objectInsideArr];
}
}
}
If it were me I would write a custom formatter to get it into JSON format and then use NSJSONSerialization once I know it is valid. What you posted is so far from valid there is no way it would work. I'm surprised they are returning it in that format, do they provide some kind of library for consuming their services?
If you want something even simpler, I can give you my CGIJSONObject library that will handle JSON using reflection - you just need to mirror the keys in APIs with your classes andit is good to go.
I've got a question regarding parsing a JSON response within iOS5.
Currently, I'm following this guide here to help me parse the JSON response returned from a third-party mapping service.
Everything works, except that the JSON response returned by the third-party server is somewhat different from the one shown in the guide itself.
In a nutshell, the overall structure of the entire JSON response looks something like this:
{
"directions": [....],
"messages": [....],
"routes":
{
"features": [
{
"attributes": {....},
"geometry":
{
"paths": [....]
}
}
]
}
}
This is the actual JSON query URL.
By using this line of code,
NSDictionary * jsonResponse = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&error];
I am able to sucessfully get the jsonResponse dictionary to report that it has 3 key/value pairs, but my ultimate goal is to retrieve the array stored in 'routes.features.geometry.paths'.
This is my current code block that gets the final set of array values:
NSDictionary * jsonResponse = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&error];
NSArray * jsonArray = [jsonResponse valueForKeyPath:#"routes.features.geometry.paths"];
jsonArray = [jsonArray objectAtIndex:0];
jsonArray = [jsonArray objectAtIndex:0];
I was wondering if anyone might have a better idea of how I should go about doing this in a more elegant fashion?
Thanks a lot in advance!
You can't just use it as JSON object because it will be working as JSON (Plain String) and you need to parse it so for your problem you can do like this to directly go to paths
NSArray *arr = [[[[jsonResponse objectForKey:#"routes"] objectForKey:#"features"] objectForKey:#"geometry"] objectForKey:#"paths"];
Now you can access your paths data from "arr" array
UPDATE:
NSArray *arr = [[[[[jsonResponse objectForKey:#"routes"] objectForKey:#"features"] objectAtIndex:0] objectForKey:#"geometry"] objectForKey:#"paths"];
as features element is an Array so traverse array first then goto its elements