How to let user to modify the text in UITableView cells - ios

Question

I have a question regarding uitable view.
I am implementing an app which is similar to the address book app.I am able to present the table view in editing mode. I want to let the user to edit the text in the cells in editing mode. I know that in order to edit the text in the cells, I need a textfield. I have created a textfield.
My question is:
what should I do in order to present that textfield in the cells.
what are the methods I need to implement in order to present that text field in the table view in editing mode.
Once I am done with editing ,How can I update the data which is in my contacts view controller(contains all the contacts).The saving should persist in the address book. For this question I know that I need to implement some delegate method,But I am not sure how to do that.
Please have a look at the following code,so that you will have an idea about my problem.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath: (NSIndexPath *)indexPath
{
[tableView setSeparatorColor:[UIColor clearColor]];
//[self.tableView setEditing: YES animated: YES];
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"Cell"];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
// Configure the cell...
if(isEditingOn) {
if(cell == nil)
cell = [self getCellContentView:CellIdentifier];
UILabel *lblTemp1 = (UILabel *)[cell viewWithTag:1];
UITextField *textfield1=(UITextField*)[cell viewWithTag:2];
if(indexPath.row == 0) {
lblTemp1.text = #"Name";
textfield1.text = myContact.name;
}
else if(indexPath.row == 1) {
lblTemp1.text = #"Phone";
textfield1.text = myContact.phone;
}
else if(indexPath.row == 2) {
lblTemp1.text = #"Email";
textfield1.text = myContact.email;
}
}
else {
if(indexPath.row == 0) {
cell.textLabel.text = myContact.name;
}
else if(indexPath.row == 1) {
cell.textLabel.text = myContact.phone;
}
else if(indexPath.row == 2) {
cell.textLabel.text = myContact.email;
}
}
return cell;
}
- (UITableViewCell *) getCellContentView:(NSString *)cellIdentifier {
CGRect CellFrame = CGRectMake(0, 0, 60, 20);
CGRect Label1Frame = CGRectMake(10, 10, 180, 25);
UILabel *lblTemp;
UITableViewCell *cell = [[[UITableViewCell alloc] initWithFrame:CellFrame reuseIdentifier:cellIdentifier] autorelease];
lblTemp = [[UILabel alloc] initWithFrame:Label1Frame];
lblTemp.tag = 1;
[cell.contentView addSubview:lblTemp];
[lblTemp release];
CGRect TextFieldFrame=CGRectMake(240, 10, 60, 25);
UITextField *textfield;
textfield=[[UITextField alloc]initWithFrame:TextFieldFrame];
textfield.tag=2;
textfield.placeholder = #"";
[cell.contentView addSubview:textfield];
}

Answer 1

This is a really complex question to answer this fully and in-depth with code examples, but I'll try to point you in the right direction.
1) Add a UITextField as a subview of your table cell when you create the cell in the tableView:cellForRowAtIndexPath: method (I assume that's what your getCellContentView: method is for). Set a tag on your UITextField that matches the row index of the cell and make your tableviewcontroller the delegate for the cell. Set the textfield to hidden. (remember to set the tag each time the cell is requested, not just the first time you create it).
2) In the tableView:didSelectRowAtIndexPath: method, grab the cell using tableViewCellForRowAtIndexPath and then show the textfield inside it (you may have to do some view traversal to get it) and call becomeFirstResponder on the textfield.
3) When the user has typed something, your textfielddelegate methods will be fired. You can look at the tag on the textfield to work out which row the field belongs to and then update the dat source with the new text. Then just reload the table to hide the textfield and update the cell content.
If you know how to use custom table cell subclasses then you can make your life a bit easier by creating a custom cell that already contains a textfield and has an property for accessing it, but otherwise the technique will be mostly the same.
Also, tableView:didSelectRowAtIndexPath: won't normally fire when a tableview is in edit mode unless you set tableView.allowsSelectionDuringEditing = YES;

Answer 2

It's better to use 2 UITableViewCells, The first one for view and the last for edit mode.
Also we will depend on the variable rowToEdit which refers to the current editing row. (in my case one cell is allowed to be edited at the same time)
let us begin:
First I depend on accessoryButtonTap action to edit the row:
var rowToEdit: IndexPath? = nil
override func tableView(_ tableView: UITableView, accessoryButtonTappedForRowWith indexPath: IndexPath) {
// End edit mode if one cell being in edit mode other than this one
if let row = self.rowToEdit {
// return current edit cell to view mode
self.rowToEdit = nil
self.tableView.reloadRows(at: [row], with: .automatic)
}
self.rowToEdit = indexPath
self.tableView.reloadRows(at: [self.rowToEdit!], with: .automatic)
}
Differentiate between the 2 modes when you will load the cell:
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if indexPath == self.rowToEdit {
let cellId = "ContactEditTableViewCell"
let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath as IndexPath) as! ContactEditTableViewCell
cell.accessoryType = .none
self.configEditCell(cell: cell, indexPath: indexPath)
return cell
} else {
let cellId = "ContactTableViewCell"
let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath as IndexPath) as! ContactTableViewCell
self.configCell(cell: cell, indexPath: indexPath)
return cell
}
}
Additional option if you want to change the height based on mode:
override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
if indexPath == self.rowToEdit {
return 120
} else {
return 70
}
}
Last option to add Save and Cancel buttons:
I added them to each cell, So I pass a reference to the ContactTable to each cell.
#IBAction func btnSave_click(_ sender: UIButton) {
// save the record
btnCancel_click(sender)
}
#IBAction func btnCancel_click(_ sender: UIButton) {
let tmp = self.tbl.rowToEdit
self.tbl.rowToEdit = nil
self.tbl.tableView.reloadRows(at: [tmp!], with: .automatic)
}