Chapter 7 ViewTaskController

EEE · May 23rd, 2011, 01:23 PM

In the ViewTaskController, as depicted on pg. 172 in figure 7-5, I'd like to split up the table into 3 sections and show the 6 rows of data split up over 3 table sections with section titles like the following:

Section 1
Text
Priority

Section 2
Due Date
Location

Section 3
Hi-Pri Task
Tasks due sooner than this one

Can anyone please explain exactly how this would be done in order to define the three section titles, section the table into 3 sections, define exactly how many rows per section, and push the correct data to each row in each section?

I know where the numberOfSectionsInTableView and numberOfRowsInSection code is in ViewTaskController.m, but I don't understand how to define the exact sections and data for each section in order to achieve the 3 sections as mentioned above.

Thanks in advance for your help.

thepianoguy · May 23rd, 2011, 10:26 PM

The following changes to ViewTaskController.m produce the result you appear to be looking for. (Changes and additions in bold)

Code:

#pragma mark Table view methods

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 3;
}


// Customize the number of rows in the table view.
- (NSInteger)tableView:(UITableView *)tableView 
    numberOfRowsInSection:(NSInteger)section {
    return 2;
}

-(NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
    return [NSString stringWithFormat:@"Section %d",section + 1];
}


// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView 
         cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    
    static NSString *CellIdentifier = @"Cell";
    
    UITableViewCell *cell = 
        [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] 
                 initWithStyle:UITableViewCellStyleValue2 
                 reuseIdentifier:CellIdentifier] autorelease];
    }
    
    // Set up the cell...
    int choice = indexPath.section * 2 + indexPath.row;
    switch (choice) {
        case 0:
            cell.textLabel.text = @"Text";
            cell.detailTextLabel.text = managedTaskObject.text;
            break;
        case 1:
            cell.textLabel.text = @"Priority";
            
            // Get the priority number and convert it to a string
            NSString* priorityString=nil;
            
            switch ([managedTaskObject.priority intValue]) {
                case 0:
                    priorityString = @"None";
                    break;
                case 1:
                    priorityString = @"Low";
                    break;
                case 2:
                    priorityString = @"Medium";
                    break;
                case 3:
                    priorityString = @"High";
                    break;
                default:
                    break;
            }
            
            cell.detailTextLabel.text = priorityString;
            [priorityString release];
            
            break;
        case 2:
            cell.textLabel.text = @"Due Date";
            
            //  Create a date formatter to format the date from the picker
            NSDateFormatter* df = [[NSDateFormatter alloc] init];
            [df setDateStyle:NSDateFormatterLongStyle];
            cell.detailTextLabel.text = 
                [df stringFromDate:managedTaskObject.dueDate ];
            [df release];
            
            break;
        case 3:
            cell.textLabel.text = @"Location";
            Location* locationObject = managedTaskObject.location;
            if (locationObject!=nil)
            {
                cell.detailTextLabel.text = locationObject.name;
            }
            else {
                cell.detailTextLabel.text = @"Not Set"; 
                
            }
            
            break;   
        case 4:
            // Show hi-pri tasks alert
            cell.detailTextLabel.text = @"Hi-Pri Tasks";
            break;
        case 5:
            // Show sooner tasks alert
            cell.detailTextLabel.text = @"Tasks due sooner than this one";
            break;
            
        default:
            break;
    }
    
    return cell;
}

Bob

EEE · May 23rd, 2011, 11:00 PM

Thank you very much for your reply and for the code instructions. It worked perfectly! However, I may have made my example too symmetrical in section sizes and names. Can you elaborate with the following section examples. I'm having a hard time figuring out how to get specific with the Section titles and changing up the number of rows and order of rows rather than an even 2 rows per section as I had mistakenly mentioned earlier. Thanks in advance for your help. Much appreciated.

Alpha
Text

Bravo
Due Date
Location
Priority

Tango
Hi-Pri Task
Tasks due sooner than this one

thepianoguy · May 24th, 2011, 12:54 AM

The following sets up the tableView as you described. Note that the reordering of the items also required reworking or the -didSelectRowAtIndexPath... method as well for the proper controller to be called. If there is anything that is not clear let me know.

Code:

#pragma mark Table view methods -- Edited to resolve forum question

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 3;
}


// Customize the number of rows in the table view.
- (NSInteger)tableView:(UITableView *)tableView 
 numberOfRowsInSection:(NSInteger)section {
    NSInteger returnValue = 0;
    switch (section) {
        case 0:
            returnValue = 1;
            break;
        case 1:
            returnValue = 3;
            break;
        case 2:
            returnValue = 2;
            
        default:
            break;
    }
    return returnValue;
}

-(NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
    NSString *sectionHeader = nil;
    switch (section) {
        case 0:
            sectionHeader = @"Alpha";
            break;
        case 1:
            sectionHeader = @"Bravo";
            break;
        case 2:
            sectionHeader = @"Tango";
            break;
        default:
            break;
    }
    
    return sectionHeader;
}


// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView 
         cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    
    static NSString *CellIdentifier = @"Cell";
    
    UITableViewCell *cell = 
    [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] 
                 initWithStyle:UITableViewCellStyleValue2 
                 reuseIdentifier:CellIdentifier] autorelease];
    }
    
    // Set up the cell...
    
    switch (indexPath.section) {
        case 0:
            cell.textLabel.text = @"Text";
            cell.detailTextLabel.text = managedTaskObject.text;
            break;
        case 1:
            switch (indexPath.row) {
                case 0:
                    cell.textLabel.text = @"Due Date";                    
                    //  Create a date formatter to format the date from the picker
                    NSDateFormatter* df = [[NSDateFormatter alloc] init];
                    [df setDateStyle:NSDateFormatterLongStyle];
                    cell.detailTextLabel.text = 
                    [df stringFromDate:managedTaskObject.dueDate ];
                    [df release];
                    
                    break;
                case 1:
                    cell.textLabel.text = @"Location";
                    Location* locationObject = managedTaskObject.location;
                    if (locationObject!=nil)
                    {
                        cell.detailTextLabel.text = locationObject.name;
                    }
                    else {
                        cell.detailTextLabel.text = @"Not Set"; 
                        
                    }
                    
                    break;
                case 2:
                    cell.textLabel.text = @"Priority";
                    
                    // Get the priority number and convert it to a string
                    NSString* priorityString=nil;
                    
                    switch ([managedTaskObject.priority intValue]) {
                        case 0:
                            priorityString = @"None";
                            break;
                        case 1:
                            priorityString = @"Low";
                            break;
                        case 2:
                            priorityString = @"Medium";
                            break;
                        case 3:
                            priorityString = @"High";
                            break;
                        default:
                            break;
                    }
                    
                    cell.detailTextLabel.text = priorityString;
                    [priorityString release];
                    break;
                default:
                    break;
            }
            break;
        case 2:
            switch (indexPath.row) {
                case 0:
                    // Show hi-pri tasks alert
                    cell.detailTextLabel.text = @"Hi-Pri Tasks";
                    break;
                case 1:
                    // Show sooner tasks alert
                    cell.detailTextLabel.text = @"Tasks due sooner than this one";
                    break;
                default:
                    break;
            }
            
        default:
            break;
    }
    
    return cell;
}

- (void)tableView:(UITableView *)tableView 
    didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    
    //  Deselect the currently selected row according to the HIG
    [tableView deselectRowAtIndexPath:indexPath animated:NO];
    
    //  Based on the section and selected row, choose which controller to push
    switch (indexPath.section) {
        case 0:
        {
            EditTextController* etc = [[EditTextController alloc] 
                                       initWithStyle:UITableViewStyleGrouped];
            etc.managedObject = self.managedTaskObject;
            etc.keyString=@"text";
            etc.managedObjectContext = self.managedObjectContext;
            [self.navigationController pushViewController:etc animated:YES];
            [etc release];
            break;
        }
        case 1:
            switch (indexPath.row) {
                case 0:
                {
                    EditDateController* edc = [[EditDateController alloc] init];
                    
                    edc.managedTaskObject = self.managedTaskObject;
                    edc.managedObjectContext = self.managedObjectContext;
                    
                    [self.navigationController pushViewController:edc animated:YES];
                    [edc release];
                    break;
                }
                case 1:
                {
                    EditLocationController* elc = [[EditLocationController alloc] init];
                    elc.managedObjectContext = self.managedObjectContext;
                    elc.managedTaskObject = self.managedTaskObject;
                    [self.navigationController pushViewController:elc animated:YES];
                    [elc release];
                    break;
                }
                case 2:
                {
                    EditPriorityController* epc = 
                    [[EditPriorityController alloc]
                     initWithStyle:UITableViewStyleGrouped];
                    epc.managedTaskObject = self.managedTaskObject;
                    epc.managedObjectContext = self.managedObjectContext;
                    
                    [self.navigationController pushViewController:epc animated:YES];
                    [epc release];
                    break;
                }
                
                    
                default:
                    break;
            }
            break;
        case 2:
            switch (indexPath.row) {
                case 0:
                {
                    
                    UIAlertView* alert = 
                    [[[UIAlertView alloc] initWithTitle:@"Hi-Pri Tasks" 
                                                message:nil
                                               delegate:self 
                                      cancelButtonTitle:@"OK" 
                                      otherButtonTitles:nil  ] autorelease];
                    
                    // Use Fetched property to get a list of high-pri tasks
                    NSArray* highPriTasks = managedTaskObject.highPriTasks;
                    NSMutableString* alertMessage = 
                    [[[NSMutableString alloc] init] autorelease];
                    
                    // Loop through each hi-pri task to create the string for 
                    // the message
                    for (Task * theTask in highPriTasks)                
                    {
                        [alertMessage appendString:theTask.text];
                        [alertMessage appendString:@"\n"];
                    }
                    
                    alert.message = alertMessage;
                    [alert show];
                    
                    break;    
                }
                case 1:
                {
                    
                    UIAlertView* alert =
                    [[[UIAlertView alloc] initWithTitle:@"Tasks due sooner" 
                                                message:nil
                                               delegate:self 
                                      cancelButtonTitle:@"OK" 
                                      otherButtonTitles:nil  ] autorelease];
                    NSMutableString* alertMessage =
                    [[[NSMutableString alloc] init] autorelease];
                    
                    // need to get a handle to the managedObjectModel to use the stored
                    // fetch request
                    TasksAppDelegate* appDelegate =
                    [UIApplication sharedApplication].delegate;
                    NSManagedObjectModel* model = appDelegate.managedObjectModel;
                    
                    // Get the stored fetch request
                    NSDictionary* dict = 
                    [[NSDictionary alloc] 
                     initWithObjectsAndKeys:managedTaskObject.dueDate,  
                     @"DUE_DATE",nil];
                    
                    NSFetchRequest* request =
                    [model fetchRequestFromTemplateWithName:@"tasksDueSooner"
                                      substitutionVariables:dict];
                    
                    [dict release];
                    
                    NSError* error;
                    NSArray* results = 
                    [managedObjectContext executeFetchRequest:request error:&error];
                    
                    // Loop through eachtask to create the string for the message
                    for (Task * theTask in results)                
                    {
                        [alertMessage appendString:theTask.text];
                        [alertMessage appendString:@"\n"];
                    }
                    alert.message = alertMessage;
                    [alert show];
                    
                    break;    
                }
                default:
                    break;
            }
        default:
            break;
    }
}

Bob

EEE · May 24th, 2011, 01:32 AM

Bob,

That all worked perfectly and is exactly what I needed. Thanks for taking the time to re-tweak this. This really helps a lot. Thank you very much, and thanks for the good catch on the didSelectRowAtIndexPath method for the correct controller to be called. Much appreciated!

Evan