TweetFollow Us on Twitter

A Dashboard Widget that Reads and Saves its Preferences

Volume Number: 24
Issue Number: 10
Column Tag: Dashboard Widgets

A Dashboard Widget that Reads and Saves its Preferences

Create a Dashboard Widget that can save and read data after restarting it.

by Mihalis Tsoukalos

Introduction

In this article I am going to illustrate how to create a Dashboard Widget that saves its preferences. After saving the preferences, you will learn how to read and use the saved information and display the selected data in the front side of the Widget. The name of the Widget is "Save Prefs".

The files that compose the Widget

Figure 1 shows the files of the Widget as well as their sizes (in bytes).


Figure 1: The files that compose the "Save Prefs" Widget.

As you can understand by looking at Figure 1, the "Save Prefs" Widget is relatively simple. You should notice that it has a directory -the AppleClasses directory- that contains three JavaScript files. Apple provides the contents of the AppleClasses directory and the only thing that you should do is to copy the three JavaScript files inside your Widget's directory.

Also, as you will see in the next section, you will have to include them in the main HTML file of your Widget. Source code for this project can be downloaded from ftp.mactech.com/src/mactech/volume24_2008/24.10.sit. The source archive contains the following files:

SavePrefs.html file

SavePrefs.js file

SavePrefs.css

Info.plist

You may think that the SavePrefs.js JavaScript file contains a lot of code but most of the code is typical when creating a Dashboard Widget. The showPrefs() and hidePrefs() functions are used for watching and hiding the back side of the Widget and you usually have to copy and paste their definitions to your new Widgets.

The SavePrefs.css file

The CSS file looks pretty simple. Nevertheless, if you make small mistakes to the CSS code the Widget may misbehave very badly! I am saying this because I had some problems with the #OptionPopup declaration. Due to my wrong declarations the option list was displayed outside of the Widget area and I could not see it at all!

The Info.plist file

The Info.plist file is pretty simple and is as follows:

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN"
"http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>BackwardsCompatibleClassLookup</key>
<true/>
<key>CFBundleDisplayName</key>
<string>Save Prefs</string>
<key>CFBundleIdentifier</key>
<string>com.mtsouk.widget.saveprefs</string>
<key>CFBundleName</key>
<string>Save Prefs</string>
<key>CFBundleShortVersionString</key>
<string>1.0</string>
<key>CFBundleVersion</key>
<string>1.0</string>
<key>CloseBoxInsetX</key>
<integer>14</integer>
<key>CloseBoxInsetY</key>
<integer>16</integer>
<key>MainHTML</key>
<string>SavePrefs.html</string>
</dict>
</plist>

Explaining the Technique

The presented technique uses the following two JavaScript methods:

  • widget.preferenceForKey(keyName): This method tries to read the value of a key, if the value is already saved.
  • widget.setPreferenceForKey(value, keyName): This method sets the value of a key. The Dashboard Reference suggests that you should pass null in order to delete an existing key.

Apple suggests that you utilize the widget.preferenceForKey(keyName) function using the following practice:

   if(window.widget)
   {
       var optionString = widget.preferenceForKey("optionString");
       if (optionString && optionString.length > 0)
       {
           optionText.innerText = optionString;
       }
   }

Similarly, Apple suggests that you use the widget.setPreferenceForKey(value, keyName) function as follows:

   if(window.widget)
   {
       widget.setPreferenceForKey("Hello MacTech!","optionString");
   }

A word of advice: The described method stores strings without any encryption. It is therefore not a secure way to store your sensitive information.

The following lines of JavaScript code declare two global variables, called glassDoneButton and whiteInfoButton, respectively. Each of the two variables holds one button. The first declaration creates the done button whereas the second declaration creates that little info (i) button that you frequently see in Widgets.

   var glassDoneButton;
   var whiteInfoButton;

The following JavaScript code implements the two button definitions:

   glassDoneButton = new AppleGlassButton(document.getElementById("doneButton"),
            "Done", hidePrefs);
   whiteInfoButton = new AppleInfoButton(document.getElementById("infoButton"),
            document.getElementById("front"), "white", "white", showPrefs);

The following command line output text explains where Dashboard keeps the Widget stored information using the described method:

mtsouk$ ll ~/Library/Preferences/widget-com.mtsouk.widget.saveprefs.plist
-rw————
    1 mtsouk   mtsouk         98 May 18 22:13
    /Users/mtsouk/Library/Preferences/widget-com.mtsouk.widget.saveprefs.plist
mtsouk$

The contents of the widget-com.mtsouk.widget.save-prefs.plist file are the following:

   <?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>OptionString</key>
   <string>Option 4</string>
</dict>
</plist>


Figure 2: The final look of the presented Widget (both sides).

A word of advice: You can now understand why it is extremely important to have a uniquely defined CFBundleIdentifier key for every Widget that you create or use. The above plist file that stores the Widget preferences uses the CFBundleIdentifier value as a part of its filename. It is also important to have a UNIQUE CFBundleName key because if you try to install a Widget with the same CFBundleName key, Dashboard will ask you if you want to replace the existing Widget (the other, different Widget with the same CFBundleName name)!!

Conclusions

This article presents an advanced technique that lets you store and retrieve your Dashboard Widget preferences or any other data you like. The presented Widget uses the back side for selecting the desired preference and its front side for displaying it but you can choose to implement it any way you want.

Bibliography and References

Introduction to Dashboard Programming Topics: http://developer.apple.com/documentation/AppleApplications/Conceptual/Dashboard_ProgTopics/Introduction/Introduction.html

Introduction to Dashboard Tutorial: http://developer.apple.com/documentation/AppleApplications/Conceptual/Dashboard_Tutorial/Introduction/chapter_1_section_1.html

Developing Dashboard Widgets: http://developer.apple.com/macosx/dashboard.html

Apple Dashboard Page: http://developer.apple.com/appleapplications/dashboard/

Debugging Dashboard Widgets: http://developer.apple.com/technotes/tn2005/tn2139.html

Dashboard Sample Code: http://developer.apple.com/samplecode/AppleApplications/idxDashboard-date.html#//apple_ref/doc/uid/TP30000925-TP30000418-TP40001366

Disclaimer: The presented Widget code is a modified version of the "GoodBye" Widget provided by Apple and located on your Tiger machine (but not in Mac OS X 10.5), inside the "/Developer/Examples/Dashboard/GoodbyeWorld/3-SavingPreferences" folder. The "Save Prefs" Widget that is presented in this article has four options and, as you saw, it is a little bit more complicated than the "GoodBye" Apple Widget.


Mihalis Tsoukalos lives in Greece with his wife Eugenia and enjoys digital photography and writing articles. He is the author of the "Programming Dashboard Widgets" eBook. You can reach him at tsoukalos@sch.gr.

 
AAPL
$98.38
Apple Inc.
-0.64
MSFT
$43.89
Microsoft Corpora
-0.09
GOOG
$585.61
Google Inc.
-4.99

MacTech Search:
Community Search:

Software Updates via MacUpdate

Drive Genius 3.2.4 - Powerful system uti...
Drive Genius is an OS X utility designed to provide unsurpassed storage management. Featuring an easy-to-use interface, Drive Genius is packed with powerful tools such as a drive optimizer, a... Read more
Vitamin-R 2.15 - Personal productivity t...
Vitamin-R creates the optimal conditions for your brain to work at its best by structuring your work into short bursts of distraction-free, highly focused activity alternating with opportunities for... Read more
Toast Titanium 12.0 - The ultimate media...
Toast Titanium goes way beyond the very basic burning in the Mac OS and iLife software, and sets the standard for burning CDs, DVDs, and now Blu-ray discs on the Mac. Create superior sounding audio... Read more
OS X Yosemite Wallpaper 1.0 - Desktop im...
OS X Yosemite Wallpaper is the gorgeous new background image for Apple's upcoming OS X 10.10 Yosemite. This wallpaper is available for all screen resolutions with a source file that measures 5,418... Read more
Acorn 4.4 - Bitmap image editor. (Demo)
Acorn is a new image editor built with one goal in mind - simplicity. Fast, easy, and fluid, Acorn provides the options you'll need without any overhead. Acorn feels right, and won't drain your bank... Read more
Bartender 1.2.20 - Organize your menu ba...
Bartender lets you organize your menu bar apps. Features: Lets you tidy your menu bar apps how you want. See your menu bar apps when you want. Hide the apps you need to run, but do not need to... Read more
TotalFinder 1.6.2 - Adds tabs, hotkeys,...
TotalFinder is a universally acclaimed navigational companion for your Mac. Enhance your Mac's Finder with features so smart and convenient, you won't believe you ever lived without them. Tab-based... Read more
Vienna 3.0.0 RC 2 :be5265e: - RSS and At...
Vienna is a freeware and Open-Source RSS/Atom newsreader with article storage and management via a SQLite database, written in Objective-C and Cocoa, for the OS X operating system. It provides... Read more
VLC Media Player 2.1.5 - Popular multime...
VLC Media Player is a highly portable multimedia player for various audio and video formats (MPEG-1, MPEG-2, MPEG-4, DivX, MP3, OGG, ...) as well as DVDs, VCDs, and various streaming protocols. It... Read more
Default Folder X 4.6.7 - Enhances Open a...
Default Folder X attaches a toolbar to the right side of the Open and Save dialogs in any OS X-native application. The toolbar gives you fast access to various folders and commands. You just click... Read more

Latest Forum Discussions

See All

Note Review
Note Review By Jennifer Allen on July 29th, 2014 Our Rating: :: TOO SIMPLEiPhone App - Designed for the iPhone, compatible with the iPad Note is a note taking app that’s a little too short on features to be worth its asking price... | Read more »
Chainsaw Warrior Goes on Sale & Ther...
Chainsaw Warrior Goes on Sale & There’s a Chance to Win a Copy of the Original Board Game Posted by Jennifer Allen on July 29th, 2014 [ permalink | Read more »
It Came From Canada: Tiny Tower Vegas
If you go to a casino, you might make a lot of money. If you run a casino, you’re guaranteed to make a lot of money. The choice seems pretty obvious. So while waiting for your shady real estate deals to move forward, get prepared with Tiny Tower... | Read more »
Z Hunter Review
Z Hunter Review By Lee Hamlet on July 29th, 2014 Our Rating: :: RIGHT ON TARGETUniversal App - Designed for iPhone and iPad While it might not necessarily break new ground, Z Hunter has enough tricks up its sleeve to ensure that... | Read more »
Huge Update Comes To Duet, Adding 48 New...
Huge Update Comes To Duet, Adding 48 New Stages Posted by Jennifer Allen on July 29th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Sharknado: The Video Game Available Now....
Sharknado: The Video Game Available Now. Seriously. Posted by Rob Rich on July 29th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Frog Orbs 2 Review
Frog Orbs 2 Review By Nadia Oxford on July 29th, 2014 Our Rating: :: THIS MAGIC IS A TAD MONOTONOUS Universal App - Designed for iPhone and iPad Frog Orbs 2 is repetitive, but younger players should enjoy it nonetheless.   | Read more »
Puzzix Review
Puzzix Review By Jennifer Allen on July 29th, 2014 Our Rating: :: NICE IDEAUniversal App - Designed for iPhone and iPad A little like Tetris, Puzzix is all about piecing together blocks and watching them vanish. It could do with... | Read more »
Cannonball eMail is Now Live – Works Wit...
Cannonball eMail is Now Live – Works With Gmail, Yahoo, Outlook, Hotmail, and AOL Posted by Jessica Fisher on July 29th, 2014 [ permalink ] | Read more »
To The End Review
To The End Review By Lee Hamlet on July 29th, 2014 Our Rating: :: A VICIOUS CYCLEUniversal App - Designed for iPhone and iPad To The End will test players’ patience, timing, and dedication as they try to navigate all 13 levels in... | Read more »

Price Scanner via MacPrices.net

Apple Updates MacBook Pro with Retina Display...
Apple today updated its MacBook Pro with Retina display with faster processors and double the amount of memory in both entry-level configurations. MacBook Pro with Retina display features a Retina... Read more
Up to $250 price drop on leftover 15-inch Mac...
B&H Photo has dropped prices on 2013 15″ Retina MacBook Pros by as much as $250 off original MSRP. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.3GHz Retina MacBook Pro: $2349... Read more
Updated MacBook Pro Price Trackers
We’ve updated our MacBook Pro Price Trackers with the latest information on prices, bundles, and availability on the new 2014 models from Apple’s authorized internet/catalog resellers as well as... Read more
Apple updates MacBook Pros with slightly fast...
Apple updated 13″ and 15″ Retina MacBook Pros today with slightly faster Haswell processors. 13″ models now ship with 8GB of RAM standard, while 15″ MacBook Pros ship with 16GB across the board. Most... Read more
Apple drops price on 13″ 2.5GHz MacBook Pro b...
The Apple Store has dropped their price for the 13″ 2.5GHz MacBook Pro by $100 to $1099 including free shipping. Read more
Apple drops prices on refurbished 2013 MacBoo...
The Apple Store has dropped prices on Apple Certified Refurbished 13″ and 15″ 2013 MacBook Pros, with model now available starting at $929. Apple’s one-year warranty is standard, and shipping is free... Read more
iOS 8 and OS X 10.10 To Support DuckDuckGo As...
Writing for Quartz, Dan Frommer reports that Apple’s forthcoming iOS 8 and OS X 10.10 operating systems version updates will allow users to select DuckDuckGo as their default search engine. He notes... Read more
U.K. Hospital Using iPods and iPads To Record...
British news journal GazetteLive’s. Ian McNeal notes that the old “an apple a day keeps the doctor away” proverb is being turned on its head at http://southtees.nhs.uk/hospitals/james-cook/ James... Read more
13-inch 2.5GHz MacBook Pro on sale for $1099,...
Best Buy has the 13″ 2.5GHz MacBook Pro available for $1099.99 on their online store. Choose free shipping or free instant local store pickup (if available). Their price is $100 off MSRP. Price is... Read more
Roundup of Apple refurbished MacBook Pros, th...
The Apple Store has Apple Certified Refurbished 13″ and 15″ MacBook Pros available for up to $400 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free. Their prices... Read more

Jobs Board

Sr Software Lead Engineer, *Apple* Online S...
Sr Software Lead Engineer, Apple Online Store Publishing Systems Keywords: Company: Apple Job Code: E3PCAK8MgYYkw Location (City or ZIP): Santa Clara Status: Full Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
Sr. Product Leader, *Apple* Store Apps - Ap...
**Job Summary** Imagine what you could do here. At Apple , great ideas have a way of becoming great products, services, and customer experiences very quickly. Bring Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.