data from server is not getting displayed in tableview - ios

Question

i have 2 screens ,in 1 st when i click a button it should go to 2 nd screen get data from server and display in table view in 2 nd screen.but with following code i am unable to display data in table view
#import "FirstTableViewController.h"
#interface FirstTableViewController ()<NSXMLParserDelegate>
#property(nonatomic,strong)NSXMLParser*xmlparse;
#property(nonatomic,strong)NSMutableString*tempstr;
#property(nonatomic,strong)NSMutableArray*arr;
#end
#implementation FirstTableViewController
- (void)viewDidLoad {
[super viewDidLoad];
NSMutableURLRequest*req=[[NSMutableURLRequest alloc]init];
NSURL*url=[NSURL URLWithString:#"http://www.thomas-bayer.com/sqlrest/CUSTOMER/"];
[req setURL:url];
[[[NSURLSession sharedSession]dataTaskWithRequest:req completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
// SMXMLDocument *document = [SMXMLDocument documentWithData:data error:&error];
NSString*str=[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
_xmlparse=[[NSXMLParser alloc]initWithData:data];
_xmlparse.delegate=self;
[_xmlparse parse];
}] resume];
[_table reloadData];
}
- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{
_tempstr=[[NSMutableString alloc]initWithString:string];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(nullable NSString *)namespaceURI qualifiedName:(nullable NSString *)qName attributes:(NSDictionary<NSString *, NSString *> *)attributeDict;{
if([elementName isEqualToString:#"CUSTOMER"]){
self.tempstr=[[NSMutableString alloc]init];
}
if([elementName isEqualToString:#"CUSTOMERList"]){
self.arr=[[NSMutableArray alloc]init];
}
}
- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(nullable NSString *)namespaceURI qualifiedName:(nullable NSString *)qName;{
if([elementName isEqualToString:#"CUSTOMER"]){
[_arr addObject:self.tempstr];
self.tempstr=nil;
}
// NSLog(#"arr is %#",self.arr);
}
#pragma mark - Table view data source
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return self.arr.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"Cel" forIndexPath:indexPath];
cell.textLabel.text=[self.arr objectAtIndex:indexPath.row];
return cell;
}
#end

Answer 1

do two things
First
- (void)viewDidLoad {
[super viewDidLoad];
arr = [NSMutableArray array]; // initilize the memory of array
NSMutableURLRequest*req=[[NSMutableURLRequest alloc]init];
NSURL*url=[NSURL URLWithString:#"http://www.thomas-bayer.com/sqlrest/CUSTOMER/"];
[req setURL:url];
[[[NSURLSession sharedSession]dataTaskWithRequest:req completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
// SMXMLDocument *document = [SMXMLDocument documentWithData:data error:&error];
NSString*str=[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
_xmlparse=[[NSXMLParser alloc]initWithData:data];
_xmlparse.delegate=self;
[_xmlparse parse];
}] resume];
}
Second
- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(nullable NSString *)namespaceURI qualifiedName:(nullable NSString *)qName;{
if([elementName isEqualToString:#"CUSTOMER"]){
[_arr addObject:self.tempstr];
self.tempstr=#"";
}
if(arr.count >0)
{
dispatch_async(dispatch_get_main_queue(), ^{
[_table reloadData];
});
}
}