UITableView: hide header from empty section
i have a UITableView, that displays expenses from a current month (see screenshot):
My problem is with the header for empty sections. is there any way to hide them? The data is loaded from coredata.
this is the code that generates the header title:
TitleForHeader
-(NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section{
if ([tableView.dataSource tableView:tableView numberOfRowsInSection:section] == 0) {
return nil;
} else {
NSDate *today = [NSDate date ];
int todayInt = [dataHandler getDayNumber:today].intValue;
NSDate *date = [NSDate dateWithTimeIntervalSinceNow:(-(todayInt-section-1)*60*60*24)];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setLocale:[[NSLocale alloc] initWithLocaleIdentifier:[[NSLocale preferredLanguages] objectAtIndex:0]]];
[dateFormatter setTimeStyle:NSDateFormatterNoStyle];
[dateFormatter setDateStyle:NSDateFormatterMediumStyle];
NSString *formattedDateString = [dateFormatter stringFromDate:date];
return formattedDateString;}
}
ViewForHeader
-(UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section{
if ([tableView.dataSource tableView:tableView numberOfRowsInSection:section] == 0) {
return nil;
} else {
UIView *headerView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 312, 30)];
UILabel *title = [[UILabel alloc]initWithFrame:CGRectMake(4, 9, 312, 20)];
UIView *top = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 312, 5)];
UIView *bottom = [[UIView alloc]initWithFrame:CGRectMake(0, 5, 312, 1)];
[top setBackgroundColor:[UIColor lightGrayColor]];
[bottom setBackgroundColor:[UIColor lightGrayColor]];
[title setText:[expenseTable.dataSource tableView:tableView titleForHeaderInSection:section]];
[title setTextColor:[UIColor darkGrayColor]];
UIFont *fontName = [UIFont fontWithName:@"Cochin-Bold" size:15.0];
[title setFont:fontName];
[headerView addSubview:title];
[headerView addSubview:top];
[headerView addSubview:bottom];
return headerView;
}
}
heightForHeader
- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section {
NSLog(@"Height: %d",[tableView.dataSource tableView:tableView numberOfRowsInSection:section] == 0);
if ([tableView.dataSource tableView:tableView numberOfRowsInSection:section == 0]) {
return 0;
} else {
return 30;
}
}
numberOfRowsInSection
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
int rows = 0;
for (Expense* exp in [dataHandler allMonthExpenses]) {
if ([exp day].intValue == section) {
rows++;
}
}
return rows;
}
sebastian
You have to set tableView:heightForHeaderInSection:
to 0 for the appropriate sections. This is something which changed fairly recently and got me in a couple places. From UITableViewDelegate
it says...
Prior to iOS 5.0, table views would automatically resize the heights of headers to 0 for sections where tableView:viewForHeaderInSection: returned a nil view. In iOS 5.0 and later, you must return the actual height for each section header in this method.
So you'll have to do something like
- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section {
if ([tableView.dataSource tableView:tableView numberOfRowsInSection:section] == 0) {
return 0;
} else {
// whatever height you'd want for a real section header
}
}
What if in – tableView:viewForHeaderInSection:
you return nil
if the section count is 0.
EDIT :
You can use numberOfRowsInSection
for obtaining the number of elements in the section.
EDIT:
Probably you should return nil also in titleForHeaderInSection
if numberOfRowsInSection
is 0.
EDIT: Did you implement the following method?
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
EDIT : Swift 3 example
override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
switch section {
case 0:
if self.tableView(tableView, numberOfRowsInSection: section) > 0 {
return "Title example for section 1"
}
case 1:
if self.tableView(tableView, numberOfRowsInSection: section) > 0 {
return "Title example for section 2"
}
default:
return nil // when return nil no header will be shown
}
return nil
}
In my strange situation I have to return:
viewForHeaderInSection -> nil
viewForFooterInSection -> nil (don't forget about footer!)
heightForHeaderInSection -> 0.01 (not zero!)
heightForFooterInSection -> 0.01
only in this case empty sections disappear completely
Take a look at the method -[UITableViewDelegate tableView:heightForHeaderInSection:]
. Especially the note that accompanies its documentation:
Prior to iOS 5.0, table views would automatically resize the heights of headers to 0 for sections where
tableView:viewForHeaderInSection:
returned anil
view. In iOS 5.0 and later, you must return the actual height for each section header in this method.