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Adding a Text Field Setting

We now need to add a second item in this array, which will represent the first actual preference field. We’re going to start with a simple text field.

If you single-click the PreferenceSpecifiers row in the editor pane (don’t do this, just keep reading), and press return to add a child, the new row will be inserted at the beginning of the list, which is not what we want. We want to add a row at the end of the array.

To add the row, click the disclosure triangle to the left of Item 0 to close it, and then select Item 0 and press return, which will give you a new sibling row after the current row (see Figure 12–17). As usual, when the item is added, a drop-down menu appears, showing the default value of Text Field.

Figure 12–17. Adding a new sibling row to Item 0

Click somewhere outside the drop-down menu to make it go away, and then click the disclosure triangle next to Item 1 to expand it. You’ll see that it contains a Type row set to PSTextFieldSpecifier. This is the Type value used to tell the Settings application that we want the user to edit this setting in a text field. It also contains two empty rows for Title and Key (see Figure 12–18).

Figure 12–18. Our text field item, expanded to show the type, title, and key

Select the Title row, then double-click in the whitespace of the Value column. Type in Username to set the Title value. This is the text that will appear in the Settings app.

Now do the same for the Key row (no, that’s not a misprint, you’re really looking at a key called Key). For a value, type in username (note the lowercase first letter). Remember

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that user defaults work like a dictionary. This entry tells the Settings application which key to use when it stores the value entered in this text field.

Recall what we said about NSUserDefaults? It lets you store values using a key, similar to an NSDictionary. Well, the Settings application will do the same thing for each of the preferences it saves on your behalf. If you give it a key value of foo, then later in your application, you can request the value for foo, and it will give you the value the user entered for that preference. We will use this same key value later to retrieve this setting from the user defaults in our application.

NOTE: Notice that our Title has a value of Username and our Key has a value of username. This uppercase/lowercase difference will happen frequently. The Title is what appears on the screen,

so the capital U makes sense. The Key is a text string we’ll use to retrieve preferences from the user defaults, so all lowercase makes sense there. Could we use all lowercase for Title? You bet. Could we use all capitals for Key? Sure! As long as you capitalize it the same way when you save

and when you retrieve, it doesn’t matter which convention you use for your preference keys.

Now, select the last of the three Item 1 rows (the one with a Key of Key) and press return to add another entry to our Item 1 dictionary, giving this one a key of AutocapitalizationType and a value of None. This specifies that the text field shouldn’t attempt to autocapitalize what the user types in this field. Note that as soon as you start typing AutocapitalizationType, Xcode presents you with a list of matching choices, so you can simply pick one from the list instead of typing the whole name.

Create one last new row, and give it a key of AutocorrectionType and a value of No. This will tell the Settings application not to try to autocorrect values entered into this text field. When you do want the text field to use autocorrection, change the value in this row to Yes. Again, Xcode presents you with a list of matching choices as you begin entering

AutocorrectionType.

When you’re finished, your property list should look like the one shown in Figure 12–19.

Figure 12–19. The finished text field specified in Root.plist

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Adding an Application Icon

Before we try out our new setting, let’s add an application icon to the project. You’ve done this before.

Save Root.plist, the property file you just edited. Then make your way into the source code archive and into the 12 – AppSettings folder. Drag the file icon.png into your project’s AppSettings folder and, when prompted, have Xcode copy the icon.

Next, open the Supporting Files folder, and click the file AppSettings-info.plist. When the property list editor appears, expand the Icon files row. Next, select the Icon files row, press return to create a new item inside it, and change the new item’s value to icon.png.

That’s it. Now compile and run the application by selecting Product Run. Press the home button, and then tap the icon for the Settings application. You will find an entry for our application, which uses the application icon we added earlier (see Figure 12–3). Click the AppSettings row, and you will be presented with a simple settings view with a single text field, as shown in Figure 12–20.

Figure 12–20. Our root view in the Settings application after adding a group and a text field

Quit the simulator, and go back to Xcode. We’re not finished yet, but you should now have a sense of how easy it is to add preferences to your application. Let’s add the rest

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of the fields for our root settings view. The first one we’ll add is a secure text field for the user’s password.

Adding a Secure Text Field Setting

Click Root.plist to return to your setting specifiers (don’t forget to turn on Show Raw Keys/Values, assuming your friends at XcodeCorp have reset this). Collapse Item 0 and Item 1. Now select Item 1. Press C to copy it to the clipboard, and then press V to paste it back. This will create a new Item 2 that is identical to Item 1. Expand the new item, and change the Title to Password and the Key to password (one with a capital P and one with a lowercase p).

Next, add one more child to the new item. Remember that the order of items does not matter, so feel free to place it directly below the Key item you just edited. To do this, select the Key/password row, and then hit return.

Give the new item a Key of IsSecure (note the leading uppercase I), and change the Type to Boolean. Now change its Value from NO to YES, which tells the Settings application that this field needs to be a password field, rather than just an ordinary text field. Our finished Item 2 is shown in Figure 12–21.

Figure 12–21. Our finished Item 2, a text field designed to accept a password

Adding a Multivalue Field

The next item we’re going to add is a multivalue field. This type of field will automatically generate a row with a disclosure indicator. Clicking it will take you down to another table where you can select one of several rows.

Collapse Item 2, select the row, and then press return to add Item 3. Use the popup attached to the Key field to select Multi Value, and expand Item 3 by clicking the disclosure triangle.

The expanded Item 3 already contains a few rows. One of them, the Type row, is set to PSMultiValueSpecifier. Look for the Title row and set its value to Protocol. Then find the Key row, and give it a value of protocol. The next part is a little tricky, so let’s talk about it before we do it.

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We’re going to add two more children to Item 3, but they will be Array type nodes, not String type nodes, as follows:

One array, called Titles, will hold a list of the values from which the user can select.

The other array, called Values, will hold a list of the values that actually are stored in the user defaults.

So, if the user selects the first item in the list, which corresponds to the first item in the Titles array, the Settings application will actually store the first value from the Values array. This pairing of Titles and Values lets you present user-friendly text to the user but actually store something else, like a number, date, or different string.

Both of these arrays are required. If you want them both to be the same, you can create one array, copy it, paste it back in, and change the key so that you have two arrays with the same content but stored under different keys. We’ll actually do just that.

Select Item 3 (leave it open) and press return to add a new child. You’ll see that once again, Xcode is aware of the type of file we’re editing and seems to anticipate what we want to do, because the new child row already has its Key set to Titles and is configured to be an Array. Just what we wanted! Expand the Titles row and hit return to add a child node. Repeat this four more times, so you have a total of five child nodes. All five nodes should be String type and should contain the following values: HTTP, SMTP, NNTP, IMAP, and POP3.

Once you’ve entered all five nodes, collapse Titles, and select it. Then press C to copy it, and press V to paste it back. This will create a new item with a key of Titles - 2. Double-click Titles - 2, and change it to Values.

We’re almost finished with our multivalue field. There’s just one more required value in the dictionary, which is the default value. Multivalue fields must have one—and only one—row selected. So, we need to specify the default value to be used if none has yet been selected, and it needs to correspond to one of the items in the Values array (not the Titles array, if they are different). Xcode already added a DefaultValue row when we created this item, so all we need to do now is give it a value of SMTP. Figure 12–22 shows our version of Item 3.

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Figure 12–22. Our finished Item 3, a multivalue field designed to let the user select from one of five possible values

Let’s check our work. Save the property list, and build and run the application again. When your application starts up, press the home button and launch the Settings application. When you select AppSettings, you should see three fields on your root-level view (see Figure 12–23). Go ahead and play with your creation, and then let’s move on.

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