Relational objects in Objective C - ios

I have two classes that define Video and Cue objects. I get my data through an JSON API. The backend is written in Rails and has a one-to-many relationship between Video and Cues.
The data I get is structured like this:
{ "true":
[
{
"id" : 3,
"title" : "My Title"
[
{ "cues":
[
{
"id": 117,
"time" : "12.81",
"video_id" : 3
},
{
"id": 118,
"time" : "14.34",
"video_id" : 3
}
]
}
]
}
]
}
I have a method in Video.m that gets the JSON array, puts it in a dictionary and converts the dictionary to an array of Video objects.
+(id) getVideos {
NSURL *videoURL = [NSURL URLWithString:#"http://localhost:3000/myEndPoint"];
NSData *jsonData = [NSData dataWithContentsOfURL:videoURL];
NSError *error = nil;
NSDictionary *videoDictionary = [NSJSONSerialization JSONObjectWithData:jsonData options:0 error:&error];
NSMutableArray *videos = [NSMutableArray array];
for (NSDictionary *dict in videoDictionary[#"true"]) {
NSString *title = [dict objectForKey:#"title"];
Video *newVideo = [[Video alloc] initWithTitle:title];
[videos addObject: newVideo];
}
return videos;
}
How should I format the cues so that I can get specific cues from a Video, like in a relational sort of way if possible, if not then just the best practise. In Rails it would be video.cues. Can I do this in Objective C?
Would be perfect if I could end up having the ability to do something like:
Cue *currentCue = video.cues[0];

Add a property to your Video class: NSArray *cues. And change your init method to initWithTitle:(NSString*)title andCues:(NSArray*)cues. That way you'll be able to do exactly that: video.cues[0]

Related

How to fetch the data from JSON using key in iPhone

Hey I'm new to iPhone and I have been trying to parse the below JSON for displaying different types of Survey using my below code. I have two tables, in first table i want to display all the "Surveys_title" text value, and once user will tap on any survey title row then it should display their particular question and question ID in my second table. Like i have two questions for "Survey1" and three questions for "Survey2". Using my code, i am able to display all survey titles in my first table but i am getting problem that how to store array of objects for all the survey types individually. here, I have created one custom class "Survey". Thank you for any help you can give me.
JSON :
{
"Surveys": [
{
"Surveys_title": "Survey1",
"Questions": [
{
"event_sq_qns_id": 1,
"questions": "What is your primary job title/focus?"
},
{
"event_sq_qns_id": 2,
"questions": "Effectiveness of the speakers?"
}
]
},
{
"Surveys_title": "Survey2",
"Questions": [
{
"event_sq_qns_id": 3,
"questions": "What is this?"
},
{
"event_sq_qns_id": 4,
"questions": "Who are you?"
},
{
"event_sq_qns_id": 5,
"questions": "what is your name?"
}
]
},
{
"Surveys_title": "Survey3",
"Questions": [
{
"event_sq_qns_id": 6,
"questions": "What is your primary job?"
},
{
"event_sq_qns_id": 7,
"questions": "Effectiveness of the speakers?"
}
]
}
]
}
here is my code :
#import <Foundation/Foundation.h>
#interface Surveys : NSObject
#property (nonatomic, retain) NSString *surveys_question_id;
#property (nonatomic, retain) NSString *questions;
#end
- (void) fetchingSurveyQuestionsFromServer
{
[MBProgressHUD showHUDAddedTo:self.view animated:YES];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0), ^{
NSDictionary *results;
#try {
NSString *filePath = [[NSBundle mainBundle] pathForResource:#"survey" ofType:#"json"];
NSData *responseData = [NSData dataWithContentsOfFile:filePath];
//parse the json data
NSError *error;
NSDictionary* json = [NSJSONSerialization JSONObjectWithData:responseData
options:kNilOptions
error:&error];
results= [json objectForKey:#"Surveys"];
}
#catch (NSException *exception) {
NSLog(#"Exception in %s %#",__FUNCTION__,exception);
}
dispatch_async (dispatch_get_main_queue (),
^{
arraySurveys = [[NSMutableArray alloc] init];
arraySurveys_type = [[NSMutableArray alloc] init];
NSString *surveys_title_name;
for (NSDictionary *dict in results) {
NSDictionary *questionDict = dict[#"Questions"];
surveys_title_name = dict[#"Surveys_title"];
NSLog(#"Questions dictionary = %#", questionDict);
NSLog(#"Survey type is = %#", surveys_title_name);
for (NSDictionary *dict1 in questionDict) {
Surveys *surveys = [[Surveys alloc] init];
surveys.surveys_question_id = [dict1 objectForKey:#"event_sq_qns_id"];
surveys.questions = [dict1 objectForKey:#"survey_questions"];
[arraySurveys addObject:surveys];
}
[arraySurveys_type addObject:surveys_title_name];
}
[MBProgressHUD hideHUDForView:self.view animated:YES];
[tblSurveys reloadData];
});
});
}
Using above code, all the questions are adding directly to the arraySurveys. please help me how can i differentiate according to the Surveys title.
Thanks.
Use like this ....
SBJSON *json = [[SBJSON alloc] init];
NSMutableDictionary *jsonObject = [json objectWithString:response ];
NSMutableArray *Surveys=[jsonObject valueForKey:#"Surveys"];
NSMutableArray * Surveys_title =[[NSMutableArray alloc]init];
NSMutableArray * Questions =[[NSMutableArray alloc]init];
for (NSDictionary *dictnory in Surveys) {
[Surveys_title addObject:[dictnory objectForKey:#"Surveys_title"]];
[Questions addObject:[dictnory objectForKey:#"Questions"]];
}

Store App names in NSArray from JSON DATA which Stored in NSDictionary

I have retrive following response form Server in JSON format which I have sucessfully store in NSDictionary.
{
"#companyName" = "MobileAPPSDeveloper";
"#generatedDate" = "8/6/13 2:41 AM";
"#version" = "1.0";
application = (
{
"#apiKey" = 234FXPQB36GHFF2334H;
"#createdDate" = "2013-03-01";
"#name" = FirstApp;
"#platform" = iPhone;
},
{
"#apiKey" = 3PF9WDY234546234M3Z;
"#createdDate" = "2013-02-01";
"#name" = SecondAPP;
"#platform" = iPhone;
},
{
"#apiKey" = NXGQXM2347Y23234Q4;
"#createdDate" = "2013-05-22";
"#name" = ThirdApp;
"#platform" = Android;
}
);
}
This is method I have used.
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
[self convertDataIntoDictionary:responseData];
}
-(void)convertDataIntoDictionary:(NSData*)data{
NSDictionary *dictionary;
if (data.length>0) {
NSError *parsingDataError;
dictionary = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&parsingDataError];
if (parsingDataError) {
// [ErrorAlert showError:parsingDataError];
NSString *recievedString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(#"Data Conversion Error When Parsing: %#", recievedString);
}
}
NSLog(#"Data back from server\n %#",dictionary);
NSArray *applicationDetails = dictionary[#"application"];
}
I can not go further then this?
I would like to get All NAME of APPS in Array.
Any help would be appreciate.
The basics of parsing JSON is:
{ }- dis represents dictionary
( )- dis represents array
So in your JSON, there is a dictionary at the root and inside it has a key application which cbntains an Array.
NSArray *applicationArray = [dictionary objectForKey:#"application"];
NSMutableArray *mutableAppNamesArray = [[NSMutableArray alloc]init];
Inside this array there are three NSDictionary at every index:
for(NSDictionary *dict in applicationArray){
NSString *appName = [dict objectForKey:#"#name"];
NSLog(#"app name : %#", appName);
[mutableAppNamesArray addObject:appName];
}
NSArray * appNamesArray = [NSArray arrayWithArray:mutableAppNamesArray];
I think this is not a proper format for JSON. JSON objects usually contain ':' instead of '='
Example :-
{
products_id: "476",
products_model: "XOLO Play",
products_price: "15499.0000",
products_image: "xolo-play-play-t1000-.jpg",
products_date_available: null,
products_last_modified: "2013-08-04 06:04:11",
products_date_added: "2013-08-04 06:03:10",
manufacturers_id: "17",
products_status: "1",
products_rating: null,
category_id: "11"
},
{
products_id: "18",
products_model: "Nokia Lumia 820",
products_price: "8990.0000",
products_image: "samsung-galaxy-ace-duos-gsm-mobile-phone-large-1.jpg",
products_date_available: null,
products_last_modified: "2013-07-30 03:45:28",
products_date_added: "2013-01-23 00:52:00",
manufacturers_id: "2",
products_status: "1",
products_rating: "3",
category_id: "11"
},
But if you still need to parse it then you might try as below:
First get into the array
by NSDictionary *array = [allValues objectForKey:#"application"]; then each index to NSDictionary and then object for key. If its your server response than try to make it in the proper JSON format.

Parsing JSON information in Objective C (multiple levels)

I'm able to parse a part of my JSON file but if I want to go deeper in the structure, I'm lost. Here's my JSON :
{
"album":[
{
"album_titre":"Publicité",
"album_photo":"blabla.jpg",
"album_videos":[
{
"titre_video":"Chauffage Compris",
"duree_video":"01'25''",
"photo_video":"chauffage.jpg",
"lien_video":"www.bkjas.jhas.kajs"
},
{
"titre_video":"NIFFF 2012",
"duree_video":"01'43''",
"photo_video":"nifff.jpg",
"lien_video":"www.bkjas.jhas.kajs"
}
]
},
{
"album_titre":"Events",
"album_photo":"bloublou.jpg",
"album_videos":[
{
"titre_video":"Auvernier Jazz",
"duree_video":"01'15''",
"photo_video":"auvernier.jpg",
"lien_video":"www.bkjas.jhas.kajs"
},
{
"titre_video":"NIFFF 2011",
"duree_video":"01'03''",
"photo_video":"nifff2011.jpg",
"lien_video":"www.bkjas.jhas.kajs"
}
]
},
{
"album_titre":"Culture",
"album_photo":"bilibl.jpg"
},
{
"album_titre":"Postproduction",
"album_photo":"bizoubzou"
}
]
}
And here's my objective-c code :
- (void)fetchedData:(NSData *)responseData {
NSError* error;
NSDictionary *document = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&error];
if (document==nil)
{
NSLog( #"oops\n%#", error);
}
NSArray *album = document[#"album"];
for( NSDictionary *albumDictionary in album )
{
[album_titre addObject:albumDictionary[#"album_titre"]];
[album_photo addObject:albumDictionary[#"album_photo"]];
for( NSDictionary *album_videosDictionary in albumDictionary[#"album_videos"])
{
[titre_video addObject:album_videosDictionary[#"titre_video"]];
[duree_video addObject:album_videosDictionary[#"duree_video"]];
[photo_video addObject:album_videosDictionary[#"photo_video"]];
[lien_video addObject:album_videosDictionary[#"lien_video"]];
}
}
[self.tableView reloadData];
}
What I can't achieve is to create an array with for example contains all "titre_video" corresponding to "album_titre":"publicité". So it should contain "Chauffage Compris" and "Nifff 2012".
I know it's a kind of easy question but I've search for a while and still not able to do it.
Thank's a lot.
Nicolas
The key is to understand JSON structure:
{ } - - this means the underlying object is a dictionary.
[ ] -- this means the underlyingobject is an array
- (void)fetchedData:(NSData *)responseData {
NSError* error;
NSDictionary *document = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&error];
// all titre:video for album_titre:publicite
NSArray *albumArray = [document objectForKey:#"album"];
NSDictionary *dict = [albumArray objectAtindex:0];
NSArray *videos = [dict objectForKey:#"album_videos"];
// to fetch Videos inside album_videos
// here you will get al the videos inside key titre_video
NSMutableArray *titreVideoArray = [[NSMutableArray alloc]init];
for(int i=0; i< videos.count; i++){
NSDictionary *dict = [videos objectAtindex:i];
NSArray *titreVideos = [dict objectForKey:#"titre_video"];
[titreVideoArray addObject: titreVideos];
}
}
It seems you want to fetch all the videos relating to different "album_titre".
I would suggest you to use NSPredicate .
NSArray *videos = [self videosArrayForTitle:#"Publicité" albumArray:albumArray];
Here we pass title and the albumArray from above to fetch us the videos array.
- (NSArray *)videosArrayForTitle:(NSString *)title albumArray:(NSArray *)albumArray{
NSPredicate *resultPredicate=[NSPredicate predicateWithFormat:#"SUBQUERY(album_titre, $content, $content CONTAINS %#).#count > 0", title];
NSArray *searchResults=[albumArray filteredArrayUsingPredicate:resultPredicate];
NSArray *videos = [searchResults objectForKey:#"album_videos"];
return videos;
}
{ } denotes NSDictionary
[ ] denotes NSArray
Copy your json into a text edit file and go in deep. You can use NSLog() to print the data, when you go deep.
Hope it will help you.

ios development - How to do JSON parser?

I'm new to ios development. Now I get a JSON file from server.
I use NSDictionary to get objects. When I debug, I could get "name", "address" values.
But I don't know how can I get all "dish" elements from "recommendation" Object? In java development, I know recommendation is an object, and "dish" is an array element. But I don't know what happen in ios.
{
"results": [
{
"name": "ollise",
"address": "columbia university",
"geo": [
{
"coordinates": 40
},
{
"coordinates": 70
}
],
"logo": "http:\/\/a0.twimg.com\/profile_images\/3159758591\/1548f0b16181c0ea890c71b3a55653f7_normal.jpeg",
"recommendation": [
{
"dish": "dish1"
},
{
"dish": "dish2"
}
],
}
]
}
By the way, in JSON, I store URL of an image in "logo", but I cannot get the value when debugging. Should I use some special format?
[Restaurant setname:[Dict objectForKey:#"name"]] // I could get name
[Restaurant setlogo:[Dict objectForKey:#"logo"]] // I can get nothing!
This is the way to do it
NSDictionary *response = [NSJSONSerialization JSONObjectWithData:yourData options:NSJSONReadingMutableLeaves error:nil];
NSDictionary *results = [[response objectForKey:#"results"] objectAtIndex:0];
NSString *name = [response objectForKey:#"name"];
//... get other objects
NSArray *recommendation = [results objectForKey:#"recommendation"];
NSDictionary *recommendation1 = [recommendation objectAtIndex:0];
NSDictionary *recommendation2 = [recommendation objectAtIndex:1];
NSString *dish = [recommendation1 objectForKey#"dish"];
NSString *dish1 = [recommendation2 objectForKey#"dish"];
[Restaurant setname:name];
NSString *logo = [results objectForKey:#"logo"];
[Restaurant setlogo:logo];
The results is the same dictionary as the one in the JSON. Treat anything with braces ({}) as an NSDictionary and brackets ([]) as an NSArray. dish is not an array element, it is a key in a dictionary that is an array element.

How can I get the JSON array data from nsstring or byte in xcode 4.2?

I'm trying to get values from nsdata class and doesn't work.
here is my JSON data.
{
"count": 3,
"item": [{
"id": "1",
"latitude": "37.556811",
"longitude": "126.922015",
"imgUrl": "http://175.211.62.15/sample_res/1.jpg",
"found": false
}, {
"id": "3",
"latitude": "37.556203",
"longitude": "126.922629",
"imgUrl": "http://175.211.62.15/sample_res/3.jpg",
"found": false
}, {
"id": "2",
"latitude": "37.556985",
"longitude": "126.92286",
"imgUrl": "http://175.211.62.15/sample_res/2.jpg",
"found": false
}]
}
and here is my code
-(NSDictionary *)getDataFromItemList
{
NSData *dataBody = [[NSData alloc] initWithBytes:buffer length:sizeof(buffer)];
NSDictionary *iTem = [[NSDictionary alloc]init];
iTem = [NSJSONSerialization JSONObjectWithData:dataBody options:NSJSONReadingMutableContainers error:nil];
NSLog(#"id = %#",[iTem objectForKey:#"id"]);
//for Test
output = [[NSString alloc] initWithBytes:buffer length:rangeHeader.length encoding:NSUTF8StringEncoding];
NSLog(#"%#",output);
return iTem;
}
how can I access every value in the JSON? Please help me.
look like this ..
NSString *jsonString = #"your json";
NSData *JSONdata = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
NSError *jsonError = nil;
if (JSONdata != nil) {
//this you need to know json root is NSDictionary or NSArray , you smaple is NSDictionary
NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:JSONdata options:0 error:&jsonError];
if (jsonError == nil) {
//every need check value is null or not , json null like ( "count": null )
if (dic == (NSDictionary *)[NSNull null]) {
return nil;
}
//every property you must know , what type is
if ([dic objectForKey:#"count"] != [NSNull null]) {
[self setCount:[[dic objectForKey:#"count"] integerValue]];
}
if ([dic objectForKey:#"item"] != [NSNull null]) {
NSArray *itemArray = [dic objectForKey:#"item"]; // check null if need
for (NSDictionary *itemDic in itemArray){
NSString *_id = [dic objectForKey:#"id"]; // check null if need
NSNumber *found = (NSNumber *)[dic objectForKey:#"found"];
//.....
//.... just Dictionary get key value
}
}
}
}
I did it by using the framework : http://stig.github.com/json-framework/
It is very powerfull and can do incredible stuff !
Here how I use it to extract an item name from an HTTP request :
(where result is the JSO string)
NSString *result = request.responseString;
jsonArray = (NSArray*)[result JSONValue]; /* Convert the response into an array */
NSDictionary *jsonDict = [jsonArray objectAtIndex:0];
/* grabs information and display them in the labels*/
name = [jsonDict objectForKey:#"wine_name"];
Hope this will be helpfull
Looking at your JSON, you are not querying the right object in the object hierarchy. The top object, which you extract correctly, is an NSDictionary. To get at the items array, and the single items, you have to do this.
NSArray *items = [iTem objectForKey:#"item"];
NSArray *filteredArray = [items filteredArrayUsingPredicate:
[NSPredicate predicateWithFormat:#"id = %d", 2];
if (filteredArray.count) NSDictionary *item2 = [filteredArray objectAtIndex:0];
Try JSONKit for this. Is is extremely simple to use.
Note sure if this is still relevant, but in iOS 5, apple added reasonable support for JSON. Check out this blog for a small Tutorial
There is no need to import any JSON framework. (+1 if this answer is relevant)

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