Dev:Preferences specifier plist

This document provides the specification of the dictionaries that specify the layout of an iOS preference pane. These can be supplied statically via .plist files or dynamically via the _specifiers ivar in a subclass of PSViewController.

Root level

The root level of the plist may contain these keys:

key	type		meaning	depends
entry	dictionary		Specifier-like dictionary.	-
title	string	localizable string	Title of the preference pane.	entry ≠ nil
items	array	... of specifiers	Array of specifier dictionaries.	-

The title key is used only for the root plist, otherwise, the label value from the specifier that pushed the new pane is used.

Specifier Keys and Values

You can use any keys that your controller recognizes in the plist for further customization.

General to-do: Add explanations of each specifier and potentially a screenshot of it (gif for the spinner?).

Cell types

Must be one of the following:

PSButtonCell
PSEditTextCell
PSEditTextViewCell
PSGiantCell
PSGiantIconCell
PSGroupCell
PSLinkCell
PSLinkListCell
PSListItemCell
PSSecureEditTextCell
PSSegmentCell
PSSliderCell
PSSpinnerCell
PSStaticTextCell
PSSwitchCell
PSTitleValueCell

The cell type is determined from the class method +[PSTableCell cellTypeFromString:].

General keys

key	type		meaning	depends
cell	string	`<cell type>`	Specifier cell type.	-
label	string	localizable string	Label of specifier.	-
defaults	string	bundle ID	User defaults associated with this specifier.	-
key	string		Key of the user defaults.	defaults ≠ nil
default	any		Default value of control.	-
id	string		Specifier ID.	-
hasIcon	boolean		Whether the specifier will have an icon.	bundle ≠ nil
icon	string	filename	File name of the icon to use. Default value is `icon.png`. The height of the icon should be 29px.	hasIcon = true
get	string	selector	Getter.	-
set	string	selector	Setter.	-
enabled	boolean		Whether the control is enabled by default.	-
height	real		Height of the cell.	-
PostNotification	string		Darwin notification string to be posted when a change happens.	-
detail	string	class name	Detail controller class.	-
cellClass	string	class name	Customized cell class	-
requiredCapabilities	array	... of `<capability>`s	Required capabilities of the device such that this specifier can be shown.	-
dontIndentOnRemove	boolean		Prevents the cell from being indented when the table view is in editing mode.	-

Investigate hasIcon key dependency since all but PSGroupCell display an icon if supplied.

Keys apply to all cells unless otherwise stated in their respective subsection.

Signature and default methods for the set and get selectors:

-(void)setPreferenceValue:(id)value forSpecifier:(PSSpecifier*)specifier;
-(id)readPreferenceValue:(PSSpecifier*)specifier;

PSButtonCell

key	type		meaning	depends
action	string	selector	Action. Signature: `-(void)speciferPerformedAction:(PSSpecifier*)specifier;` or `-(void)speciferPerformedAction;`	-
confirmation	dictionary	`<confirmation>`	Definitions of the confirmation sheet before action is performed.	-
isDestructive	boolean		Whether the action to be performed is destructive. The OK button will be in red if true if less than iOS7.	confirmation ≠ nil

The confirmation value is a dictionary containing the following fields:

key	type		meaning
prompt	string	localizable string	Content of confirmation sheet.
title	string	localizable string	Title of confirmation sheet.
okTitle	string	localizable string	Title of the OK button.
cancelTitle	string	localizable string	Title of the cancel button.

To do: confirm this last table. Tests suggest "prompt" is the title, "title" is the okTitle, "okTitle" is MIA, cancelTitle works as stated. Investigate history of "isDestructive" key.

PSEditTextCell & PSSecureEditTextCell

key	type		meaning	depends
keyboard	string	{"`numbers`", "`phone`"}	Type of keyboard. nil or invalid values uses a normal keyboard.	-
autoCaps	string	{"`sentences`", "`words`", "`all`"}	Autocapitalization type for cells that requires a keyboard.	keyboard = nil
placeholder	string	localizable string	Placeholder.	-
suffix	string	localizable string	Suffix.	-
bestGuess	string	selector	Initial value of text field.	-
noAutoCorrect	boolean		Disable auto-correction.	-
isIP	boolean		Input field intended for entering IP address (Use Numbers keyboard).	-
isURL	boolean		Input field intended for entering URL (Use URL keyboard).	-
isNumeric	boolean		Input field intended for entering numbers (Use NumberPad keyboard).	-
isDecimalPad	boolean		Input field intended for entering decimal numbers (Use DecimalPad keyboard).	-
isEmail	boolean		Input field intended for entering e-mail (Use EmailAddress keyboard).	-
isEmailAddressing	boolean		?	-
prompt	string	localizable string	Setup prompt.	-
okTitle	string	localizable string	Title for OK button in setup prompt.	prompt ≠ nil
cancelTitle	string	localizable string	Title for cancel button in setup prompt.	prompt ≠ nil

To do: Check "prompt", "okTitle" and "cancelTitle" as they appear to not work on iOS 6. Are these in the correct place?
Check what "suffix" does. Find "bestGuess" selector signature. Solve the mystery of "isEmailAddressing".

PSEditTextViewCell

This specifier doesn't show a label so it is recommended to use a previous specifier to indicate what this specifier represents.

The text area expands to fit the whole cell, so setting a height key will provide more space to write.

Saved value is HTML text, <div> being the root tag block.

PSGiantCell

This specifier doesn't show a label so it is recommended to use a specifier before this one to indicate what this specifier represents.

PSGiantIconCell

This specifier uses the label key as text content.

The font in this cell is bigger than normal.

To do: Find out the actual font and icon sizes.

PSGroupCell

key	type	meaning	depends
footerText	string	Text displayed in a small font after this specifier.	-
footerAlignment	integer	0:left; 1:center; 2:right; defaults to 1.	-
headerCellClass	string	The class name to use for the header.	-
footerCellClass	string	The class name to use for the footer.	-
isStaticText	boolean	Whether the cells in this group have static text.	-

If you want to make a Image Header read this [Archived 2014-04-30 at the Wayback Machine]. Hides the group title (label key).

isStaticText is used in conjunction with PSStaticTextCell.

To do: Research "isStaticText" interaction with "PSStaticTextCell".

PSLinkCell

key	type		meaning	depends
bundle	string	filename	Bundle file name. This bundle will be loaded for additional resources.	-
internal	boolean		Directory to search for the bundle. If true, search in `/AppleInternal/Library/PreferenceBundles/`. If false, search in `/System/Library/PreferenceBundles/.`	bundle ≠ nil
isController	boolean		Whether the bundle contains a controller class.	bundle ≠ nil
overridePrincipalClass	boolean		Overrides the principal class by the detail controller when bundle has a controller.	isController = true
pane	string	class name	Edit pane class. If bundle is absent, the edit pane class is obtained from the current bundle. Default value is PSEditingPane.	detail ≠ nil
customControllerClass	string	class name	Custom controller class to use when the view become visible	-
lazy-bundle	NSBundle		A bundle. This bundle will be loaded for additional resources.	-

This specifier is useful for loading extra resources and custom code.

If none of these keys are specified, the framework will try to load a plist using the label text as name.

PSListItemCell

This specifier makes use of the get key to get the value in the runtime.

PSLinkListCell & PSSegmentCell

key	type		meaning	depends
validValues	array	...of strings	List of values to choose from.	-
validTitles	array	...of localizable strings	Titles corresponding to the list of values.	-
shortTitles	array	...of localizable strings	Short titles corresponding to the list of values, displayed in the link cell.	-
valuesDataSource	string	selector	Selector to call to get the list of values dynamically.	validValues = nil
titlesDataSource	string	selector	Selector to call to get the list of titles dynamically.	validTitles = nil
staticTextMessage	string	localizable string	The message to be added below the cells list of PSListItemsController.	cell = "`PSLinkListCell`"

valuesDataSource and titlesDataSource are performed on the target sent from -[PSListController loadSpecifiersFromPlistName:target:]. They must return an NSArray containing the values and (localized) titles respectively. Their signatures should be

-(NSArray*)dataFromTarget:(id)target;

In order to make a PSLinkListCell actually work like a list, you must supply the key-value pair

	detail = PSListItemsController;

PSSliderCell

key	type		meaning	depends
min	real		Minimum value of slider.	-
max	real		Maximum value of slider.	-
showValue	boolean		Show the value.	-
isContinuous	boolean		Change the value by steps. Possibly deprecated.	-
isSegmented	boolean		Change the value by steps.	-
segmentCount	integer		Steps count.	-
leftImage	string	filename	Image displayed next to the slider on the left.	-
rightImage	string	filename	Image displayed next to the slider on the right.	-

This specifier doesn't show a label so it is recommended to use a previous specifier to indicate what this specifier represents.

Image files must reside in the same directory. They can be symlinks to files elsewhere though. If showValue is set to true it might overlap with the right image.

To Do: figure out if the step is a constant or a proportion (1/10? 1/16?) of the slider range.

PSSpinnerCell

PSSpinnerCell is a simple cell with an animating spinner (UIActivityIndicatorView) inside it. Available only in iOS 7 (or higher)^{[citation needed]}. There is no way to start or stop the animation manually, it is always running. Therefore, this cell is meant to be dynamically inserted and deleted from a PSListController subclass.

PSStaticTextCell

This specifier uses the label key as text content.

PSSwitchCell

key	type	meaning	depends
alternateColors	boolean	Use an orange switch instead of blue.	iOS < 7
control-loading	boolean	Show an activity indicator view instead of switch (e.g. VPN cell)	-
negate	boolean	Invert the value displayed.	-

You can dynamically set the UISwitch's state by returning YES or NO in the get method. When the switch's state changes, the set method is called.

See PSSwitchCell in the Recipes section for solving an issue on iOS 7.

PSTitleValueCell

This specifier makes use of the get key to get the value in the runtime.

Miscellaneous

key	type		meaning	depends
alignment	integer		Text alignment. 0:left; 1:center; 2:right; defaults to 1.	cell ∈ {"`PSGroupCell`", "`PSStaticTextCell`"}

To do: check which specifiers support this key.

`PSSpecifier` runtime properties of plist keys

The table below only shows the keys recognized by SpecifiersForPlist when translating the plist into an array of PSSpecifiers. They may correspond to the actual properties of the specifier. If you would like to generate a PSSpecifier in runtime, some actions may differ:

keys	corresponding action
cell	Use the constructor, or change the `cellType` ivar.
label	Use the `name` declared property.
get	Use the constructor, or change the `getter` ivar.
set	Use the constructor, or change the `setter` ivar.
action	Change the `action` ivar.
default	Use the value property.
icon	`-[PSSpecifier setProperty:forKey:]` Use the iconImage and UIImage as a key and property, or `-[PSSpecifier setupIconImageWithPath:]`
autoCaps, keyboard, noAutoCorrect	`-[PSSpecifier setKeyboardType:autoCaps:autoCorrection:]`
isIP, isURL, isNumeric, isEmail, isEmailAddressing	Change the `textFieldType` ivar.
bestGuess	Change the `bestGuess` ivar of the PSTextFieldSpecifier class.
validValues, validTitles, shortTitles	`-[PSSpecifier setValues:titles:shortTitles:]`
confirmation	Create an instance of PSConfirmationSpecifier.
enabled	Must be set to YES (as NSNumber) to make the specifier interactive.

Recipes

Use the following snippet to create a PSSpecifier in the runtime:

	PSSpecifier* specifier = [PSSpecifier preferenceSpecifierNamed:@"title"
								target:self
								   set:@selector(setPreferenceValue:specifier:)
								   get:@selector(readPreferenceValue:)
								detail:Nil
								  cell:<cell type>
								  edit:Nil];
	[specifier setProperty:@YES forKey:@"enabled"];

Using @selector(setPreferenceValue:specifier:) as setter and @selector(readPreferenceValue:) as getter will ease the load on the work as the specifier will use its properties to make itself work, namely "defaults", "key", "default", "PostNotification".

PSButtonCell

The red delete button in VPN is in fact very easy to implement. All you need to do is add the following code:

@interface UITableCell : UIView
@end

@interface UIImageAndTextTableCell : UITableCell
-(id)titleTextLabel;
@end

@interface UIPreferencesTableCell : UIImageAndTextTableCell
-(void)setTarget:(id)target;
-(void)setAction:(SEL)action;
@end

@interface UIPreferencesControlTableCell : UIPreferencesTableCell
@end

@interface UIPreferencesDeleteTableCell : UIPreferencesControlTableCell
@end

@interface PSDeleteTableCell : UIPreferencesDeleteTableCell
@end

@implementation PSDeleteTableCell
-(void)setValueChangedTarget:(id)target action:(SEL)action userInfo:(NSDictionary*)info {
	[self setTarget:target];
	[self setAction:action];
}
-(UILabel*)titleTextLabel {
	UILabel* res = [super titleTextLabel];
	res.textColor = [UIColor whiteColor];
	return res;
}
@end

And add the following key-value pair to the button specifier:

	cellClass = PSDeleteTableCell;

Note that UIPreferencesDeleteTableCell no longer exists as of iOS 6.0. It appears to be replaced by a boolean on PSButtonCell, isDestructive.

PSEditTextCell & PSSecureEditTextCell

To make the Return key close the keyboard add the following method to your PSListController subclass:

- (void)_returnKeyPressed:(NSConcreteNotification *)notification {
	[self.view endEditing:YES];
	[super _returnKeyPressed:notification];
}

PSLinkCell

PSLinkCell is useful for linking to sub-preference-panes. The simplest example just needs 2 keys:

{
	cell  = PSLinkCell;
	label = "Settings-iPhone";
}

The label is the important part. When user clicked on the link cell, iPhoneOS will use the unlocalized label as the file name of the plist for the next pane. In the example above, the main settings screen will appear.

If you use just 2 keys, only plists inside Preferences can be loaded. In order to load your own plist, you must use a custom subclass of PSListController in detail:

{
	cell   = PSLinkCell;
	label  = "My Awesome Pane";
	detail = MyListController;
}

MyListController can simply be an empty subclass of PSListController:

@interface MyListController : PSListController {}
@end
@implementation MyListController
@end

The key thing is when you place MyListController inside your bundle, its bundle property will return your bundle which My Awesome Pane.plist can be found.

PSSwitchCell

Since iOS 7.0 and above the "alternateColors" key does not work. To be able to change the color of a switch, you must subclass PSSwitchTableCell in a PreferenceBundle as follows:

@interface PSTableCell : UITableViewCell
@end
@interface PSControlTableCell : PSTableCell
- (UIControl *)control;
@end
@interface PSSwitchTableCell : PSControlTableCell
- (id)initWithStyle:(int)style reuseIdentifier:(id)identifier specifier:(id)specifier;
@end

@interface SRSwitchTableCell : PSSwitchTableCell
@end

@implementation SRSwitchTableCell

-(id)initWithStyle:(int)style reuseIdentifier:(id)identifier specifier:(id)specifier { //init method
	self = [super initWithStyle:style reuseIdentifier:identifier specifier:specifier]; //call the super init method
	if (self) {
		[((UISwitch *)[self control]) setOnTintColor:[UIColor redColor]]; //change the switch color
	}
	return self;
}

@end

Then set this key-value pair for the specifier:

	cellClass = SRSwitchTableCell;

A detailed tutorial about this has been written on sharedroutine.com.

PSTitleValueCell

To display a value like Preferences -> General -> About, add the cell to your plist:

{
	cell = PSTitleValueCell;
	label = Version;
	get = "valueForSpecifier:";
}

And add the getter method to your controller:

- (NSString *)valueForSpecifier:(PSSpecifier *)specifier {
	return @"1.0";
}

Custom cells

Making a custom cell, header or footer is useful because it allows you to customize the style, add an image, etc.

All you need to do is make a class that looks like:

@interface PSTableCell : UITableViewCell
@end

@protocol PreferencesTableCustomView
- (id)initWithSpecifier:(PSSpecifier *)specifier;
- (CGFloat)preferredHeightForWidth:(CGFloat)width;
@end

@interface CustomCell : PSTableCell <PreferencesTableCustomView> {
	UILabel *_label;
}
@end

@implementation CustomCell
- (id)initWithSpecifier:(PSSpecifier *)specifier {
	self = [super initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"Cell" specifier:specifier];
	if (self) {
		_label = [[UILabel alloc] initWithFrame:[self frame]];
		[_label setLineBreakMode:UILineBreakModeWordWrap];
		[_label setNumberOfLines:0];
		[_label setText:@"You can use attributed text to make this prettier."];
		[_label setBackgroundColor:[UIColor clearColor]];
		[_label setShadowColor:[UIColor whiteColor]];
		[_label setShadowOffset:CGSizeMake(0,1)];
		[_label setTextAlignment:UITextAlignmentCenter];

		[self addSubview:_label];
		[_label release];
	}
	return self;
}

- (CGFloat)preferredHeightForWidth:(CGFloat)width {
	// Return a custom cell height.
	return 60.f;
}
@end

Then, set the cellClass, headerCellClass or footerCellClass in your specifier. For example:

...
{ 
	cell = PSGroupCell;
	footerCellClass = CustomCell;
},
...

A cell doesn't have to be specified for custom cells.

Constructing a PSLinkCell at runtime

If you want to dynamically add a specifier for a PSLinkCell that lazy-loads a bundle, you can do it like this:

PSSpecifier* specifier = [PSSpecifier preferenceSpecifierNamed:@"title"
                                                        target:self
                                                           set:NULL
                                                           get:NULL
                                                        detail:Nil
                                                          cell:PSLinkCell
                                                          edit:Nil];

[specifier setProperty:@"/System/Library/PreferenceBundles/prefs.bundle" forKey:@"lazy-bundle"];
[specifier setAction:@selector(lazyLoadBundle:)];

// Now add the specifier to your controller.

Constructing a PSLinkListCell at runtime

If you want to dynamically add a specifier for a PSLinkListCell you can do it like this:

PSSpecifier* specifier = [PSSpecifier preferenceSpecifierNamed:@"title"
                                                        target:self
                                                           set:NULL
                                                           get:NULL
                                                        detail:NSClassFromString(@"PSListItemsController")
                                                          cell:PSLinkListCell
                                                          edit:Nil];

[specifier setProperty:@YES forKey:@"enabled"];
[specifier setProperty:@"0" forKey:@"default"];		
specifier.values = [NSArray arrayWithObjects:@"0",@"1",@"2",nil];
specifier.titleDictionary = [NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:@"Title 1",@"Title 2",@"Title 3",nil] forKeys:specifier.values];
specifier.shortTitleDictionary = [NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:@"T1",@"T@",@"T3",nil] forKeys:specifier.values];
[specifier setProperty:@"kListValue" forKey:@"key"];

// Now add the specifier to your controller.

Making an editable PSListController

With this you can perform a "swipe-to-delete" on the rows.

You just have to use a subclass of PSEditableListController (which is a subclass of PSListController) for your List Controller. For example:

@interface PSViewController : UIViewController
@end
@interface PSListController : PSViewController
@end
@interface PSEditableListController : PSListController
@end
@interface MyListController : PSEditableListController
@end

@implementation MyListController
- (id)specifiers {
	if (!_specifiers) {
	//add a sample specifier to the list
		PSSpecifier* testSpecifier = [PSSpecifier preferenceSpecifierNamed:@"test"
									    target:self
									       set:NULL
									       get:NULL
									    detail:Nil
									      cell:PSTitleValueCell
									      edit:Nil];
		_specifiers = [[NSArray arrayWithObjects:testSpecifier, nil] retain];
	}
	return _specifiers;
}
@end

Please note, you will only be able to delete a specifier, if its class is either PSLinkListCell, PSListItemCell or PSTitleValueCell

However, you can make all specifier's deletable by adding the function

- (UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath {
	return UITableViewCellEditingStyleDelete;
}

To perform a custom action when the specifier gets deleted, you have to implement a method in your PSEditableListController subclass like this:

-(void)removedSpecifier:(PSSpecifier*)specifier{
	UIAlertView* alert = [[UIAlertView alloc] initWithTitle:@"Removing specifier: "
							message:[specifier name]
						       delegate:self
					      cancelButtonTitle:@"OK"
					      otherButtonTitles:nil];
	[alert show];
}

and set the deletionAction Key of the specifier:

extern NSString* PSDeletionActionKey;

/*
	construct the PSSpecifier* testSpecifier
*/

[testSpecifier setProperty:NSStringFromSelector(@selector(removedSpecifier:)) forKey:PSDeletionActionKey];

Custom Settings Libraries

Plist Only

To do: add more difficult recipes, such as using the PSGroupCell properly, and making sub-preferences using the PSLinkCell

These will work as an independent plist, when put into "/Library/PreferenceLoader/Preferences". You need no Objective C or anything for these, just the plist file. This can be useful for adding preferences to things like Cydgets. Other examples from tweaks that use just the plist can be found in that same location.

Required Structure

This is the required outline to add a custom plist to the Preferences app.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
    <dict>
        <key>entry</key>
        <dict>
            <key>cell</key>
            <string>PSLinkCell</string>
            <key>icon</key>
            <string>TweakIcon@2x.png</string>
            <key>label</key>
            <string>Tweak Name</string>
        </dict>

        <key>items</key>
        <array>
           
        </array>
        <key>title</key>
        <string>Demo</string>
    </dict>
</plist>

The various cells and items are put between the array tags.

Example with PSEditTextCell

Though there is nothing all that special about this cell, it is a good example of how to make other cells.

<dict>
    <key>cell</key>
    <string>PSEditTextCell</string>
    <key>placeholder</key>
    <string>0.2</string>
    <key>bestGuess</key>
    <string>0.2</string>
    <key>defaults</key>
    <string>com.yourname.yourtweak</string>
    <key>isDecimalPad</key>
    <true/>
    <key>key</key>
    <string>savedName</string>
    <key>label</key>
    <string>Visible Name:</string>
</dict>

This would make an input text cell for numbers. Use the keys specified above to change its properties and appearance. This goes for any cell.

External links

https://code.google.com/p/networkpx/wiki/PreferencesSpecifierPlistFormat

Root level

Specifier Keys and Values

Cell types

General keys

PSButtonCell

PSEditTextCell & PSSecureEditTextCell

PSEditTextViewCell

PSGiantCell

PSGiantIconCell

PSGroupCell

PSLinkCell

PSListItemCell

PSLinkListCell & PSSegmentCell

PSSliderCell

PSSpinnerCell

PSStaticTextCell

PSSwitchCell

PSTitleValueCell

Miscellaneous

PSSpecifier runtime properties of plist keys

Recipes

PSButtonCell

PSEditTextCell & PSSecureEditTextCell

PSLinkCell

PSSwitchCell

PSTitleValueCell

Custom cells

Constructing a PSLinkCell at runtime

Constructing a PSLinkListCell at runtime

Making an editable PSListController

Custom Settings Libraries

Plist Only

Required Structure

Example with PSEditTextCell

External links

`PSSpecifier` runtime properties of plist keys