Loading data in Component 2 after selecting component 1 picker View IOS

Question

There are Three components (projects, tasks and sub tasks )in my pickerview when I select project, I was able to get the project name and respective project ID (Project ID is in label). My requirement is I want to send the project ID to NSURL so that I can load the respective tasks that are assigned to that project ID. Here is my Below Code. ViewDidLoad:

// Code for Tasks loading
    NSString *nsTaskurllocal = @"http://test.com/";
    NSString *usrid = @"313";
    NSString * productIdString =[NSString stringWithFormat:@"%@/%@",[self.lblProjects text],usrid];
    NSLog(@"aString : %@", productIdString);
    NSString *aString = [nsTaskurllocal stringByAppendingString:productIdString];


    NSURL *nstaskurl = [NSURL URLWithString:aString];
    NSLog(@"nstaskurl : %@", nstaskurl);

    NSData *nstaskpostData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];

    NSString *nstaskpostLength = [NSString stringWithFormat:@"%lu", (unsigned long)[nstaskpostData length]];
    NSMutableURLRequest *nstaskrequest = [[NSMutableURLRequest alloc] init];
    [nstaskrequest setURL:nstaskurl];
    [nstaskrequest setHTTPMethod:@"POST"];
    [nstaskrequest setValue:nstaskpostLength forHTTPHeaderField:@"Content-Length"];
    [nstaskrequest setValue:@"application/projectpicker" forHTTPHeaderField:@"Accept"];
    [nstaskrequest setValue:@"application/jsonArray" forHTTPHeaderField:@"Content-Type"];
    [nstaskrequest setHTTPBody:nstaskpostData];


    NSError *nstaskerror = [[NSError alloc] init];
    NSHTTPURLResponse *nstaskresponse = nil;
    NSData *nstaskurlData=[NSURLConnection sendSynchronousRequest:nstaskrequest returningResponse:&nstaskresponse error:&nstaskerror];
    NSURLRequest *nstaskurlRequest = [NSURLRequest requestWithURL:nstaskurl
                                                cachePolicy:NSURLRequestReturnCacheDataElseLoad
                                            timeoutInterval:30];


    // Make synchronous request
    nstaskurlData = [NSURLConnection sendSynchronousRequest:nstaskurlRequest
                                    returningResponse:&nstaskresponse
                                                error:&nstaskerror];
    if ([nstaskresponse statusCode] >= 200 && [nstaskresponse statusCode] < 300)
    {
        NSString *nstaskresponseData = [NSJSONSerialization JSONObjectWithData:nstaskurlData
                                                                 options:NSJSONReadingAllowFragments error:&nstaskerror];

        NSArray *nstaskentries = [NSJSONSerialization JSONObjectWithData:[nstaskresponseData dataUsingEncoding:NSUTF8StringEncoding]
                                                           options:0 error:&nstaskerror];
        if(!nstaskentries)
        {
            NSLog(@"Error : %@", nstaskerror);
        }
        else{

            for (NSDictionary *nstaskentry in nstaskentries) {
                 taskID = [nstaskentries valueForKey:@"ID_TASK"];
                taskNames = [nstaskentries valueForKey:@"TASk_NAME"];

                //NSLog(@"Error : %@", taskNames); //log to see the result in console // by Kiran
            }

            _projectpicker.delegate = self;
            _projectpicker.dataSource = self;
        }

    }       else {

    }
    -(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{

    NSNumber *myProjectArrayString = [projID objectAtIndex:row];
    //NSNumber *myTaskArrayString = [taskID objectAtIndex:row];
    //NSLog(@"%@",myArrayString);
    //NSLog(@"%@",myTaskArrayString);
    lblProjects.text = [NSString stringWithFormat:@"%@",myProjectArrayString];
    //lblProjects.hidden = YES;
    lblTasks.text = [taskNames objectAtIndex:[pickerView selectedRowInComponent:1]];
    //lblTasks.text = [NSString stringWithFormat:@"%@", myTaskArrayString];
    lblSubTasks.text = [subtaskNames objectAtIndex:[pickerView selectedRowInComponent:2]];
}

Thanks in Advance Kiran Kumar

Answer 1

You need to differentiate between your total data, and your displayed data.

So, download all of your data and save it in projectNames, taskNames and subtaskNames. But also have 2 other properties: currentTaskNames and currentSubtaskNames (you don't need cProjectNames because the user can always see all project names.

After the download:

self.currentTaskNames = taskNames;
self.currentSubtaskNames = subtaskNames;

Now, when the user selects a project, filter the tasks and subtasks that are available.

switch (component) {
    case 0:
    {
        NSString *project = [projectNames objectAtIndex:row];
        self.currentTaskNames = [taskNames filteredArrayUsingPredicate:...];
        break;
    }
    case 1:
    {
        NSString *task = [taskNames objectAtIndex:row];
        self.currentSubtaskNames = [subtaskNames filteredArrayUsingPredicate:...];
        break;
    }
    case 2:
    // do something interesting
    break;
}

You need to fill in the predicates which filter out the tasks and subtasks that aren't appropriate based on the selected project and task.

---

Also, stop using labels for data storage...