I am trying to make a part of my app where if the person doesn't change the blank text in my UITextField, then he/she can't go on to the next step. Basically, I want to test the UITextField for nil text. I have used the if (text == #"") method, but if the person clicks on the UITextField but doesn't type, then the if statement doesn't work. For some reason it doesn't think the text == nil or "". Am I implementing the code wrong. Any other options. Please help!!!
You should be checking the length of the text property:
if([[textField text] length] == 0) {
//do something...
}
Here's the category I use...
#implementation NSString (NSString+Extensions)
- (BOOL)isNotBlank {
return [[self stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] length] > 0;
}
#end
This way a nil string would evaluate to false, which is correct. Creating an isBlank would return false for nil, which isn't correct.
I have write code to check the string is empty or not. This code also check for the string only space that is also empty for store name and address etc. this will help you.
NSString *stringTemp = textField.text;
stringTemp = [stringTemp stringByReplacingOccurrencesOfString:#" " withString:#""];
if ([stringTemp isEqualToString:#""]) {
NSLog(#"Empty string");
}
else{
NSLog(#"string has some content ");
}
Thanks
If I were you I would disable and enable the button while the user is typing. Imho it's better that the button looks disabled when there is no text than having the user click the button to tell him that he is not allowed to move to the next view. Most of apples own apps do it like this.
You achieve this behavior by using the UITextFieldDelegate method like this
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
// "Length of existing text" - "Length of replaced text" + "Length of replacement text"
NSInteger textLength = [aTextView.text length] - range.length + [text length];
if (textLength > 0) {
doneButton.enabled = YES;
}
else {
doneButton.enabled = NO;
}
return YES;
}
If you provide a prefilled textfield you have to enable the button in viewDidLoad (or where ever you want) and if you provide an empty field you have to disable it initally.
Related
I have many textField Inputs for the calculations I want that if any of the inputs is not a number and negative number then it show error message on button click and not to move to the other screen
There's at least a couple ways you can handle this, James.
#1) specify numeric keyboards for those specific numeric-only text fields in the storyboard / xib file
#2) set a delegate for the text field and when the user is done editing (e.g. textFieldDidEndEditing:), look at the contents of the text field and if you see anything that isn't a number, throw up a UIAlert.
One way to do this would be:
- (void)textFieldDidEndEditing:(UITextField *)textField
{
NSRange rangeOfInvalidCharacter = [textField.text rangeOfCharacterFromSet: [[NSCharacterSet decimalDigitCharacterSet] invertedSet]];
if(rangeOfInvalidCharacter.location != NSNotFound)
{
// throw up a UIAlert here
// and, if you want, erase the bogus text via:
textField.text = #"";
return;
}
// and if we get here, that means the text field contents are only digits.
}
Try this code
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
{
NSCharacterSet * set = [[NSCharacterSet characterSetWithCharactersInString:#"0123456789"] invertedSet];
if ([string rangeOfCharacterFromSet:set].location != NSNotFound) {
return NO; // For don't add this character
}
return YES; // For input a true character
}
This seems impossible, but maybe someone else has had the same problem.
Is it possible for me to accept an autocomplete programmatically, or in some way get the suggested word that pops up? My problem is that I'm capturing the return/backspace keystroke and then move focus to another textview. When enter/backspace is hit, the textview will ignore the auto-suggested word. It seems that it is only possible to accept an autocompletion by hit space/dot (and return for new row). With this code:
- (BOOL) textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range
replacementText:(NSString *)text {
NSRange textViewRange = [textView selectedRange];
// Handle newrow and backspace.
if(([text length] == 0) && (textViewRange.location== 0) && textViewRange.length==0){
// BACKSPACE KEYSTROKE
[delegate doSomethingWhenBackspace];
return NO;
}else if ([text isEqualToString:#"\n"]){
// RETURN KEYSTROKE
[delegate doSomethingWhenReturn];
return NO;
}
return YES;
}
I tried to programmatically add "space" when the return key is hit but that also ignores the auto-completed word.
else if ([text isEqualToString:#"\n"]){
// Tryin to accept autocomplete with no result.
textview.text = [textview.text stringByAppendingString:#" "];
// RETURN KEYSTROKE
[delegate doSomethingWhenReturn];
return NO;
}
Any suggestions?
Call -resignFirstResponder (i.e. [textView resignFirstResponder]) on the text view or text field which needs to accept autocomplete results: UIKit will change the .text property to include the autocorrected text.
If you want to keep the keyboard up after your first view resigns first responder, pass the firstResponder responsibility onto your next text input view with [anotherTextView becomeFirstResponder].
For backspace and space u can use this condition
if ([[text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]] length]==0)
{
[delegate doSomethingWhenBackspace];
return NO;
}
I've had a very similar problem, I was making an app that had to read every letter in a text view and I has issues when Autocomplete inserted words because it was saving it as if it was one letter.
you could add each character to an array and then check to see if any are over 1 string in length. Or you could add each character that is put in into an array and then run something like
NSString *string = text;
NSMutableArray *array = [NSMutableArray new];
for (int i=0; i<string.length; i++) {
[array addObject:[string substringWithRange:NSMakeRange(i, 1)]];
}
to add each character individually, by comparing the two arrays you could determine if autocorrect has been used and with what word/s.
Hope this will help.
I need my user to input some data like DF-DJSL so I put this in the code:
theTextField.autocapitalizationType = UITextAutocapitalizationTypeAllCharacters;
But unfortunately what happens is the first to letter type in CAPS but then letter immediately after typing the hyphen will be in lower case and then the rest return to CAPS therefore producing output like this (unless the user manually taps the shift button after typing a hyphen): DF-dJSL
How can I fix this?
Many Thanks
You don't mention which SDK you're using, but against 3.0 and above I see your desired behaviour.
That said, you could always change the text to upper case when they finish editing using the textFieldDidEndEditing method from the delegate:
- (void)textFieldDidEndEditing:(UITextField *)textField {
NSString *textToUpper = [textField.text uppercaseString];
[theTextField setText:textToUpper];
}
Or, by setting up a notification on the textfield when it changes, you could change the text as it is being typed:
// setup the UITextField
{
theTextField.delegate = self;
theTextField.autocapitalizationType = UITextAutocapitalizationTypeAllCharacters;
[theTextField addTarget:self action:#selector(textFieldDidChange:) forControlEvents:UIControlEventEditingChanged];
}
You have to do it this way since, unlike UISearchBar, UITextField doesn't implement textDidChange. Something like this, perhaps?
- (void)textFieldDidChange:(UITextField *)textField {
NSRange range = [textField.text rangeOfString : #"-"];
if (range.location != NSNotFound) {
theTextField.autocapitalizationType = UITextAutocapitalizationTypeAllCharacters;
}
}
I want to limit the character users can type in iPhone's keyboard, so I created an array of my own. e.g. The array including 0~9 and a dot to enable users to type a price. Then I can return NO for -(BOOL)textField:shouldChangeCharactersInRange:replacementString: if the replace string is not in the array.
The problem is that the backspace button is also disabled when I use this array to filter text. Any ideas about how to enable backspace button?
Another problem is that I want to let users type their names and therefore I don't want to let them switch to numbers and punctuaction (backspace button is also locked if I use an array to filter). How to disable the switch button on the keyboard (Now I just limit them to type a~z, blank and "." , but I think disable the switch button might be a better way)?
I find a way (maybe not good enough, but it can do the work for backspace function):
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
if(textField == txtChargeAmt)
{
if(string.length == 0) //backspace button is pressed
{
textField.text = [textField.text substringToIndex:(textField.text.length - 1)];
return NO;
}
for(NSString *s in arrNumberAndDot)
{
if([string isEqualToString:s])
{
return YES;
}
}
return NO;
}
else
return YES;
}
Other ideas about the backspace issue are welcomed. And how to disable the switch button then?
I guess I am not sure why you would want to use the same TextField for these two different types of input.
I would have two fields, an alphanumeric field for name entry and a numeric field for number entry.
Or am I not getting your question?
This will do what you want a little more succinctly (and efficiently):
- (BOOL)textField:(UITextField*)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString*)string
{
NSCharacterSet *validCharacterSet = [NSCharacterSet characterSetWithCharactersInString:#".0123456789"];
BOOL shouldChange =
[string length] == 0 || // deletion
textField != txtChargeAmt || // not the field we care about
[string rangeOfCharacterFromSet:validCharacterSet].location != NSNotFound;
if (!shouldChange)
{
// Tell the user they did something wrong. There's no NSBeep()
// on the iPhone :(
}
return shouldChange;
}
I'd construct that character set somewhere else so you you'd only have to do it once, but you get the idea. Anyone have any thoughts on what to do to alert the user they used an invalid character? I'm trying to solve a similar problem.
I am trying to get a string value out of a textField when the user dismisses the keyboard. However, it seems that whenever I try to get the value, I get garbage (attempting to print out textField.text gives out garbage). What could I be doing wrong?
(The control displays fine, and I can put text values into it even).
Here's my code:
-(BOOL)textFieldShouldReturn:(UITextField *)textField {
NSInteger currenttag = textField.tag;
NSLog(#"%d",textField.tag);
if (currenttag == 0) {
NSLog(#"%x %s",(unsigned int)textField.text,textField.text);
username = textField.text;
} else if (currenttag == 1) {
password = textField.text;
}
[textField resignFirstResponder];
return YES;
}
The fields username and passwords are nil NSString*'s, but since I will merely hold on to the NSStrings held by textField.text, it should be fine.
NSLog(#"text field text:%#",textField.text);
Have you tried using breakpoints? Have you tried NSLog(#"%#", textField.text); ?
Have you tried rewriting the function so it only displays the text?
Is the textField a valid object?
Inserting [textField retain]; as the 1st line will probably fix the problem. Just remember to add a [textField release]; at the end of the method.