03-15 Preparing for the Challenge Apps

03-15 Preparing for the Challenge Apps

Now you're ready to write
your own delegates.

The challenge app for

this lesson has three text
fields with customized behavior.

A zip code text field that only allows
digits with a maximum of five digits.

A dollar sign text field that begins
with the text for zero cents.

And then fills in the dollar
figure as digits are added.

And finally, a text field that can only
be edited when this switch is set to on.

Here in the first field, once I get
to five digits, I can't type anymore.

Here in the second field,
the digits fill in from right to left.

And there are always two
digits beyond the decimal.

By the way, don't forget that
Cmd+k toggles the keyboard.

In the third field, the user has to
flip this switch in order to add text.

You can see that tapping
inside the first two fields

brings up the number pad
instead of the qwerty keyboard.

You can set this in the attribute
inspector in storyboard.

Actually, let's open up
the utilities pane and

take a minute to explore
the attribute inspector.

This is a super convenient way to
configure UIkit view components.

Here you can set your placeholder text.

So you might want to put something like,
type your zip code here.

Here you can configure the clear button
like the one you saw in the Safari

search bar.

Here you can set capitalization.

If you add something
like a confirmation code,

you might want all characters
to be capitalized.

And here's the keyboard type, which for
the zip code we want set to number pad.

And just two more tips before
you move on to the challenge.

You're going to need to set
the delegates for your text fields.

If you want to do this in Storyboard
remember your delegate is

just a property.

So you're going to look for it in
Storyboard where you always look for

properties in the pop-up
connections menu.

And here under outlets you
can see your delegate.

Also for manipulating text,
you might want to revisit these

few lines of code from
the emoji text field delegate.

The NSString class has the method named
string by replacing characters in range.

It's perfect to use in
a UI text field delegate.

This method is helpful when you need
to build new strings from typed input.

In order to use this method, SWF strings
are usually used to cast to NSStrings.

In this case,

the variable newText represents
the text that will be displayed.