How to set UITextField default value to user's previous input? - ios

Question

My iOS app starts off with a pop-up message (UIAlertView) where you have to enter text in a UITextField. I would like the default value of the UITextField to be equal to the user's previous input.
Example: at 1pm, the user types "Happy" and clicks OK. When he re-opens the app at 2pm, the Text Field already has "Happy" as default value, he just needs to click OK. At 3pm, he opens the app, the default value is "Happy" but he changes it to "Angry", and then clicks OK. At 4pm, "Angry" is the default value when he opens the app.
- (void)viewDidLoad
{
[super viewDidLoad];
//Pop-up TextField
UIAlertView * alert = [[UIAlertView alloc] initWithTitle:#"Hello" message:#"How are you feeling ?" delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil];
alert.alertViewStyle = UIAlertViewStylePlainTextInput;
UITextField * machineTextFieldInit = [alert textFieldAtIndex:0];
machineTextFieldInit.placeholder = #"Mood";
[alert show];
}
Many thanks in advance for your help and advice !

Answer 1

It appears what you're looking for is a method to persist a user's data across multiple app sessions. This can be done a number of different ways:
Core Data
User Defaults
Plist File
External Server
Since the code you've supplied looks rather simple, perhaps using the NSUserDefaults will be the way to go.
To store a value in NSUserDefaults use this bit of code when the user presses the button:
- (void) alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
UITextField * machineTextField = [alertView textFieldAtIndex:0];
NSString * input = machineTextField.text;
if (input != nil)
{
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:input forKey:#"my.app.domain.machineTextField"];
[defaults synchronize];
}
}
And when you present the dialog, load the value from the defaults.
- (void)viewDidLoad
{
[super viewDidLoad];
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString * previous = [defaults objectForKey:#"my.app.domain.machineTextField"];
//Pop-up TextField
UIAlertView * alert = [[UIAlertView alloc] initWithTitle:#"Hello" message:#"How are you feeling ?" delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil];
alert.alertViewStyle = UIAlertViewStylePlainTextInput;
UITextField * machineTextFieldInit = [alert textFieldAtIndex:0];
machineTextFieldInit.placeholder = previous ? previous : #"Mood";
[alert show];
}

Answer 2

The simplest answer I can think of is the store the previous value in a class property, then when the user clicks cancel, store the value into their property
#property NSString *previousValue;
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex{
if (buttonIndex == [alertView cancelButtonIndex]){
previousText = machineTextFieldInit.text;
}
}
Then on the init of your alertview test field set
machineTextFiledInit.text = previousValue;
Haven't tested and there may be an easier way :)
Also don't forget to set previousValue to a default value for when the user clicks the first time.
Edit: If you want it to store it passed the close of the app
-(void)encodeRestorableStateWithCoder:(NSCoder *)coder
{
[coder encodeObject:previousValue forKey:#"previousVal"];
}
-(void)decodeRestorableStateWithCoder:(NSCoder *)coder
{
previousValue = [coder decodeObjectForKey#"previousVal"];
}