I have to following JSON response from a server:
{
"theSet": [
],
"Identifikation": 1,
"Name": "Casper",
"Adress": "Lovis 23",
"Location": "At home",
"Information": "The first, the second and the third",
"Thumbnail": "none",
}
I am retrieving the data like so:
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSLog(#"connectionDidFinishLoading");
NSLog(#"Succeeded! Received %d bytes of data",[data length]);
NSError *myError = nil;
NSDictionary *res = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:&myError];
news = [NSArray arrayWithObjects:[res allKeys], [res allValues], nil];
NSLog(#"%#", news);
//[mainTableView reloadData];
}
Then I want to insert all the JSON data into an array, so I can display the data in my tableview.
My tableview code:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"MainCell"];
if(cell == nil){
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:#"MainCell"];
}
cell.textLabel.text = [[news objectAtIndex:indexPath.row] objectForKey:#"Name"];
cell.detailTextLabel.text = [[news objectAtIndex:indexPath.row] objectForKey:#"Adress"];
return cell;
}
But my app crashes with the error:
-[__NSArrayI objectForKey:]: unrecognized selector sent to instance.
How can I insert the JSON object into an NSArray, so I can display it in my tableview?
EDITED:
I reviewed your code again and what I previously answered was wrong.
When generating your news, you are putting 2 NSArray objects in it. The first containing all keys, and the second containing all values in your JSON.
In order to display the names of each object in your JSON, you should be simply doing
news = [res allKeys];
jsonResult = res;
// store your json if you want to use the values!
Note they will be unordered.
On your cell, you can do:
NSString *key = [news objectAtIndex:indexPath.row];
cell.textLabel.text = key;
id object = [jsonResult valueForKey:key];
cell.detailTextLabel.text = // do something depending on your json type which can have different values
The error you have
[__NSArrayI objectForKey:]: unrecognized selector sent to instance.
Tells you everything you need to know.
This says NSArray does not understand objectForKey. If you read the documentation provided by Apple, you will see this.
Your code
cell.textLabel.text = [[news objectAtIndex:indexPath.row] objectForKey:#"Name"];
Is expecting the news NSArray to return an object that responds to objectForKey - most likely an NSDictionary. The code you have for extracting your JSon data
NSDictionary *res = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:&myError];
news = [NSArray arrayWithObjects:[res allKeys], [res allValues], nil];
Is just taking all of the dictionaries and extracting the keys into the array.
You need to look at these lines of your code - this is where you are going wrong.
Look at the NSJSONSerialization reference and the releated sample code that it links to.
I found a simple solution myself, that fits my project better:
I just did the following:
NSDictionary *res = [NSJSONSerialization JSONObjectWithData:data options:0 error:&myError];
NSArray news = [NSArray arrayWithObject:res];
and with that I am able to use the following code to display the JSON contents in my tableview.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"MainCell"];
if(cell == nil){
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:#"MainCell"];
}
cell.textLabel.text = [[news objectAtIndex:indexPath.row] valueForKey:#"name"];
cell.detailTextLabel.text = [[news objectAtIndex:indexPath.row] objectForKey:#"Location"];
return cell;
}
Related
I am trying to fill the cells of a dynamic tableview with a NSDictionary I believe, here is my method to fill the tableview:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
ResultsCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
NSData *jsonData = self.responseFromServer;
NSDictionary *json = [NSJSONSerialization JSONObjectWithData:jsonData options:kNilOptions error:nil];
NSArray *results = [json objectForKey:#"myData"];
for (NSDictionary *item in results) {
cell.title.text =[[item objectForKey:#"title"]objectAtIndex:indexPath.row];
}
// Configure the cell...
return cell;
}
If I just have
cell.title.text =[item objectForKey:#"title"];
almost works but all my titles are the same. But how it is currently I get the error:
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFString objectAtIndex:]: unrecognized selector sent to instance 0x7612940'
and im not sure what it means or how to fix it.
It seems like your Dictionary is actually an array of Dictionaries each with the key #"Title".
What you are doing right now is getting the String of each element and trying to get the index of indexPath.row, but strings do not have that method.
Since you only need the object at index indexPath.row, you can replace the whole for loop with the following line of code:
cell.title.text = [[results objectAtIndex:indexPath.row] objectForKey:#"title"];
Also, as Nicholas Hart said, in order to improve performance by a lot you should put the following lines in the code when you receive the json object so that it is only done once, and make results an instance variable that can be accessed from the tableView's delegate methods:
NSData *jsonData = self.responseFromServer;
NSDictionary *json = [NSJSONSerialization JSONObjectWithData:jsonData options:kNilOptions error:nil];
NSArray *results = [json objectForKey:#"myData"];
I have a plist with dictionary.
In the dictionary i have a string called "cellPic" that have url address of an image.
I'm trying to populate my table view with images that i put on my dropbox account & read them through the plist string.
("arrayFromPlist" is my array)
The problem is that when i run it, i'm getting an error in the console:
[__NSCFDictionary objectAtIndex:]: unrecognized selector
This is my code:
-(void) readPlistFromDocs
{
// Path to the plist (in the Docs)
NSString *rootPath =
[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES) objectAtIndex:0];
NSString *plistPath = [rootPath stringByAppendingPathComponent:#"Data.plist"];
NSLog(#"plistPath = %#",plistPath);
// Build the array from the plist
NSMutableArray *arrayFromDocs = [[NSMutableArray alloc] initWithContentsOfFile:plistPath];
if (arrayFromDocs)
{
NSLog(#"\n content of plist file from the documents \n");
NSLog(#"Array from Docs count = : %d", [arrayFromDocs count]);
}
arrayFromPlist = [[NSArray alloc] initWithArray:arrayFromDocs];
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
// Returns the number of rows in a given section.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [arrayFromPlist count];
NSLog(#"Array SIZE = %d",[arrayFromPlist count]);
}
- (UITableViewCell *)tableView:(UITableView *)aTableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [aTableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
NSURL *url = [[NSURL alloc] initWithString:[[arrayFromPlist objectAtIndex:indexPath.row] objectForKey:#"cellPic"]];
NSData *urlData = [[NSData alloc] initWithContentsOfURL:url];
[[cell imageView] setImage:[UIImage imageWithData:urlData]];
return cell;
}
My other question is - how can i load the images asynchronous when i read the url from the plist string?
I tried to find an example for that but i found only asynchronous without uisng plist.
Thanks.
Change Following line
NSDictionary *arrayFromDocs = [[NSDictionary alloc] initWithContentsOfFile:plistPath];
Best Tutorial for load the images asynchronous
Hope, this will help you..
I have a JSON file, and i need to extract values from it and display on my tableview. Everything works fine.
{
"1": {
"name": "Jemmy",
"birthday": "1994-11-23"
},
"2": {
"name": "Sarah",
"birthday": "1994-04-12"
},
"3": {
"name": "Deb",
"birthday": "1994-11-23"
},
"4": {
"name": "Sam",
"birthday": "1994-11-23"
}
}
When i display the values, it doesn't get displayed in the order of 1,2,3,4 as given in the records. It just gets displayed randomly. I have included my code below, I need it to be modified so i could display the content in the order given above. Can someone please help ?
- (void)requestSuccessfullyCompleted:(ASIHTTPRequest *)request{
NSString *responseString = [request responseString];
SBJsonParser *parser = [SBJsonParser new];
id content = [responseString JSONValue];
if(!content){
return;
}
NSDictionary *personDictionary = content;
NSMutableArray *personMutableArray = [[NSMutableArray alloc] init];
for (NSDictionary *childDictionary in personDictionary.allValues)
{
Deal *deal = [[Deal alloc] init];
deal.name=[childDictionary objectForKey:#"name"];
deal.dob=[childDictionary objectForKey:#"birthday"];
[personMutableArray addObject:deal];
}
self.personArray = [NSArray arrayWithArray:personMutableArray];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
Cell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
Person *person = [self.personArray objectAtIndex:indexPath.row];
cell = [[Cell alloc] initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:CellIdentifier];
cell.namelabel.text=person.name;
cell.doblabel.text=person.dob;
}
return cell;
}
You're not reusing your cell correctly. If the cell is being reused, you fail to configure it.
Your cellForRowAtIndexPath: should be this way:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
Cell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[Cell alloc] initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:CellIdentifier];
}
Person *person = [self.personArray objectAtIndex:indexPath.row];
cell.namelabel.text=person.name;
cell.doblabel.text=person.dob;
return cell;
}
Note that this is correct ARC code, but in pre-ARC, you need to add autorelease to the end of the [Cell alloc] line.
Try this and also correct your cellForRowAtIndexPath: for reused cells
- (void)requestSuccessfullyCompleted:(ASIHTTPRequest *)request{
NSString *responseString = [request responseString];
SBJsonParser *parser = [SBJsonParser new];
id content = [responseString JSONValue];
if(!content){
return;
}
NSDictionary *personDictionary = content;
NSMutableArray *personMutableArray = [[NSMutableArray alloc] init];
NSArray *array = [personDictionary allKeys];
NSArray * sortedArray = [array sortedArrayUsingSelector:#selector(caseInsensitiveCompare:)];
for (NSString *str in sortedArray)
{
NSDictionary *childDictionary = [personDictionary objectForKey:str];
Deal *deal = [[Deal alloc] init];
deal.name=[childDictionary objectForKey:#"name"];
deal.dob=[childDictionary objectForKey:#"birthday"];
[personMutableArray addObject:deal];
}
self.personArray = [NSArray arrayWithArray:personMutableArray];
}
You store the data from the JSON in a dictionary which doesn't store ordered data. You would have to get that data in order in an array or sort the array afterwords.
You could sort the array in which you store the dictionary data, if you wish to sort it alphabetically by name you can do this:
self.personArray = [personMutableArray sortedArrayUsingSelector:#selector(compare:)];
- (NSComparisonResult)compare:(Deal *)dealObject {
return [self.name compare:dealObject.name];
}
If you want the data to be represented just as the JSON you should do something like this:
for (int i = 1; i < [personDictionary.allValues count]; i++)
{
NSDictionary *childDictionary = [[personDictionary objectForKey:[NSString stringWithFormat:#"%d", i]];
Deal *deal = [[Deal alloc] init];
deal.name=[childDictionary objectForKey:#"name"];
deal.dob=[childDictionary objectForKey:#"birthday"];
[personMutableArray addObject:deal];
}
I get this error when i play with the searchbar that I have just implemented.. Some letters work while others will crash with the error in the title. The error seems to be here but i cannot figure out what is wrong with it : "cell.textLabel.text = info.nric;".
Someone please help =(
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
}
// Set up the cell...
if(searching){
PatientInfo *info = [copyListOfItems objectAtIndex:indexPath.row];
cell.textLabel.text = info.nric;
cell.detailTextLabel.text = [NSString stringWithFormat:#"%i, %i", info.category, info.age];
}
else {
//First get the dictionary object
NSDictionary *dictionary = [listOfItems objectAtIndex:indexPath.section];
NSArray *array = [dictionary objectForKey:#"Patients"];
PatientInfo *info = [array objectAtIndex:indexPath.row];
// NSString *cellValue = [array objectAtIndex:indexPath.row];
cell.textLabel.text = info.nric;
cell.detailTextLabel.text = [NSString stringWithFormat:#"%i, %i", info.category, info.age];
}
return cell;
}
One of the arrays that you think contains only PatientInfo objects actually contains an NSString. So when you then write info.nric, it's asking that NSString for its nric property, which of course doesn't exist. The actual error would be wherever you're mistakenly putting a string in the array (either copyListOfItems or listOfItems).
Replace with the following code, you will know what exactly is going wrong in your code:
PatientInfo *info = [copyListOfItems objectAtIndex:indexPath.row];
if((nil != info) && ([info isKindOfClass:[PatientInfo class]))
{
if([info respondsToSelector:#selector(nric)])
{
cell.textLabel.text = info.nric;
}
}
I have been trying for hours to figure this out. I have some JSON from a NSURLConnection. This is working fine and I have parsed it into an array. But I can't seem to get the array out of the connectionDidFinishLoading method. I an am getting (null) in the UITableViewCell method. I am assuming this is a scope of retain issue, but I am so new to ObjC I am not sure what to do. Any help would be greatly appreciated.
Cheers.
-(void)connectionDidFinishLoading:(NSURLConnection *)connection {
[connection release];
NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
[responseData release];
SBJSON *json = [[SBJSON alloc] init];
NSDictionary *results = [json objectWithString:responseString];
self.dataArray = [results objectForKey:#"data"];
NSMutableArray *tableArray = [[NSMutableArray alloc] initWithObjects:nil];
for (NSString *element in dataArray) {
//NSLog(#"%#", [element objectForKey:#"name"]);
NSString *tmpString = [[NSString alloc] initWithString:[element objectForKey:#"name"]];
[tableArray addObject:tmpString];
}
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
// Configure the cell.
//cell.textLabel.text = [self.tableView objectAtIndex:indexPath.row];
cell.textLabel.text = [self.tableArray objectAtIndex:indexPath.row];
NSLog(#"%#", tableArray);
return cell;
}
Solution:
After taking kubi and st3fan's advice with self.tableArray I found I had to reload the tableView with [self.tableView reloadData];
Get rid of the [connection release] in the 2nd line. The connection object comes in autoreleased, so this could cause crashes.
It looks like you've got a property named tableArray? If so, you're redeclaring the name in this method (you should have gotten a compiler warning).
On second thought, here's how the 2nd 1/2 of the method should look:
NSMutableArray *tmpArray = [[NSMutableArray alloc] initWithObjects:nil];
for (NSString *element in dataArray) {
[tmpArray addObject:[element objectForKey:#"name"]];
}
self.tableArray = tmpArray;
[tmpArray release];
In connectionDidFinishLoading: you use declare tableArray as a local variable. Therefore it will never be assigned to self.tableArray.
I had the same problem and I resolved it reloading the table.
I inserted this line at the end of connectionDidFinishLoading function
[self.tableView reloadData];
and it works.