How can i auto generate text fields - ios

Question

I'm new to iOS and I'm busy with my first app. I have a question: In the code below is there any way to have my app auto generate a text field when a button is pressed without me having to set it up first?
For example in the code below would it be possible to get input from a text field and use it in place of "field1" to auto generate another textfield.
UITextField *field1 = [[UITextField alloc] initWithFrame:CGRectMake(10, 10, 100, 30)];
field1.placeholder = #"Textbox 1";
field1.borderStyle = UITextBorderStyleRoundedRect;
[self.view addSubview:field1];
x = 10;
w = 100;
h = 30;
y = y + 60;
UITextField *field1 = [[UITextField alloc] initWithFrame:CGRectMake(x, y, w, h)];
field1.placeholder = #"Textbox 1";
field1.borderStyle = UITextBorderStyleRoundedRect;
[self.view addSubview:field1];
OK i see it was my code. In CGRectMake i replaced the values with variables which i incremented now with every button press and its more text fields, before it was adding on on top of the other thats why it seemed like it wasnt adding new text fields.
Now 2 questions on the above,
can i access the textfields individualy using this method.
Is this considered best practice or does it just use a lot of memory.

Answer 1

General Answer
Going by your question and comments, it looks like you want to keep adding an arbitrary number of fields and manage them as you go (keep them around so you can access and manipulate them). You'll still need to write code to create a field and stash it somewhere.
You can create a -createAndStoreFieldWithName: method that's called by your action. Such a method would use something similar to the code you wrote above but would store it somewhere. I'd recommend an 'NSMutableDictionary' that lives permanently in your controller, since dictionaries provide named access to their content.
This way, if you want to create a field called "Foo", your -createAndStoreFieldWithName: method would check to see if an entry named Foo already exists in the fieldsDictionary dictionary and, if not, would create the field (and add it to its superview, positioned wherever you wish) in code and call -[fieldsDictionary setObject:newlyCreatedField forKey:fieldName] to store it. That way, you can always get the field by name by asking -[fieldsDictionary objectForKey:desiredFieldName].
If you later want to remove them, use the same "get the field by name" approach to access the field, remove it from its superview, and remove it from the dictionary so it can be disposed of properly.
Of course if multiple fields with the same name can exist (ie, more than one Foo field), you'll need to add a layer of abstraction. In this case, you can use a unique identifier (like a UUID) the user never sees. The thing to figure out (which is hard to specify without more detail from you) is how you'll match the identifier to the proper field (given the possibility of multiple Foo fields, for example).
Also, you could just add the fields to the superview and loop through its -subviews array to locate fields by their label but this is anti-pattern to proper MVC design. Your controller object (the one creating the labels and adding them to other views) should be keeping track of these fields as I mentioned above, not the superview. This lets your controller be the intelligent mediator, since it knows what the fields are for and will use them (or possibly hand them off to some other controller) as it needs.
Situation-Specific Answer
BUT - consider whether individual UITextFields are the right way to go. Perhaps a UITableView with added rows is the better choice here? In this case your controller just decides there's one more row and kicks the table view to update. When asked about the cell, just give it your desired label from some labels container (maybe just a straight NSMutableArray of labels maintained by your controller - it matches array index to row index). MUCH simpler.
More detail in your question will get you more specific answers. Again, though, edit your original question - don't keep appending comments.

Answer 2

I assume you have a buttonPressed: method? Your question is not very clear, so if you'd like to clarify, I'm sure we can provide you with a better answer. Assuming you have a textField named inputField as a property of your view controller, you could do something like this:
- (void)buttonPressed:(id)sender {
NSString *currentText = self.inputField.text;
UITextField *newTextField = [[UITextField alloc] initWithFrame:CGRectMake(10, 10, 100, 30)];
newTextField.placeholder = currentText;
newTextField.borderStyle = UITextBorderStyleRoundedRect;
[self.view addSubview:newTextField];
}
This would create a new UITextField upon button press with its placeholder text set to whatever was in your other UITextField. This is assuming you just want to do this once and that you only have a single new UITextField. If you can do this multiple times, but still just want a single UITextField updated with new text, newTextField should be a property, and you check if it is not nil and alloc init if it is. If it's not nil (it already exists), you need only update the text/placeholder property with the new text.
If every time the user enters text, you need a new UITextField in a new location, the solution would be a little different. Again, all of these answers (mine and others) are making assumptions about what you are trying to achieve.
UPDATE: Allow me to update this answer appropriately, as was previously pointed out. The long-and-short of it would be to use #JoshuaNozzi's approach, as it will achieve what you're trying to do. Just updating this for completeness.