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.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Airmail 3.3.2 - Powerful, minimal email...
Airmail is an mail client with fast performance and intuitive interaction. Support for iCloud, MS Exchange, Gmail, Google Apps, IMAP, POP3, Yahoo!, AOL, Outlook.com, Live.com. Airmail was designed... Read more
Numi 3.15.1 - Menu-bar calculator suppor...
Numi is a calculator that magically combines calculations with text, and allows you to freely share your computations. Numi combines text editor and calculator Support plain English. For example, '5... Read more
Airmail 3.3.2 - Powerful, minimal email...
Airmail is an mail client with fast performance and intuitive interaction. Support for iCloud, MS Exchange, Gmail, Google Apps, IMAP, POP3, Yahoo!, AOL, Outlook.com, Live.com. Airmail was designed... Read more
Numi 3.15.1 - Menu-bar calculator suppor...
Numi is a calculator that magically combines calculations with text, and allows you to freely share your computations. Numi combines text editor and calculator Support plain English. For example, '5... Read more
TextSoap 8.4.1 - Automate tedious text d...
TextSoap can automatically remove unwanted characters, fix up messed up carriage returns, and do pretty much anything else that we can think of to text. Save time and effort. Be more productive. Stop... Read more
TextSoap 8.4.1 - Automate tedious text d...
TextSoap can automatically remove unwanted characters, fix up messed up carriage returns, and do pretty much anything else that we can think of to text. Save time and effort. Be more productive. Stop... Read more
Backblaze 4.3.0.44 - Online backup servi...
Backblaze is an online backup service designed from the ground-up for the Mac. With unlimited storage available for $5 per month, as well as a free 15-day trial, peace of mind is within reach with... Read more
Numi 3.15 - Menu-bar calculator supports...
Numi is a calculator that magically combines calculations with text, and allows you to freely share your computations. Numi combines text editor and calculator Support plain English. For example, '5... Read more
EtreCheck 3.3.3 - For troubleshooting yo...
EtreCheck is an app that displays the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to... Read more
BusyContacts 1.1.8 - Fast, efficient con...
BusyContacts is a contact manager for OS X that makes creating, finding, and managing contacts faster and more efficient. It brings to contact management the same power, flexibility, and sharing... Read more

Latest Forum Discussions

See All

The best new games we played this week
We were quite busy this week. A bunch of big mobile games launched over the past few days, alongside a few teeny surprises. There're lots of quality games to load your phone with. We've gone and picked out five of our favorites for the week. [... | Read more »
Magikarp Jump beginner's guide
Magikarp Jump is a mystifying little game. Part Tamagotchi, part idle clicker, there's not a whole lot of video game there, per se, but for some reason we can't help coming back to it again and again. Your goal is to train up a little Magikarp to... | Read more »
Goat Simulator PAYDAY (Games)
Goat Simulator PAYDAY 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: ** IMPORTANT - SUPPORTED DEVICES **iPhone 4S, iPad 2, iPod Touch 5 or better Goat Simulator: Payday is the most... | Read more »
GRID Autosport delayed until autumn
Sorry mobile racing fans -- GRID Autosport has been delayed a few months. The game is now expected to launch this fall on iOS. Feral Interactive announced that they wanted more time to work on the game's UI and overall performance before launching... | Read more »
Zombie Gunship Survival Beginner's...
The much anticipated Zombie Gunship Survival is here. In this latest entry in the Zombie Gunship franchise, you're tasked with supporting ground troops and protecting your base from the zombie horde. There's a lot of rich base building fun, and... | Read more »
Mordheim: Warband Skirmish (Games)
Mordheim: Warband Skirmish 1.2.2 Device: iOS Universal Category: Games Price: $3.99, Version: 1.2.2 (iTunes) Description: Explore the ruins of the City of Mordheim, clash with other scavenging warbands and collect Wyrdstone -... | Read more »
Mordheim: Warband Skirmish brings tablet...
Legendary Games has just launched Mordheim: Warband Skirmish, a new turn-based action game for iOS and Android. | Read more »
Magikarp Jump splashes onto Android worl...
If you're tired ofPokémon GObut still want something to satisfy your mobilePokémon fix,Magikarp Jumpmay just do the trick. It's out now on Android devices the world over. While it looks like a simple arcade jumper, there's quite a bit more to it... | Read more »
Purrfectly charming open-world RPG Cat Q...
Cat Quest, an expansive open-world RPG from former Koei-Tecmo developers, got a new gameplay trailer today. The video showcases the combat and exploration features of this feline-themed RPG. Cat puns abound as you travel across a large map in a... | Read more »
Jaipur: A Card Game of Duels (Games)
Jaipur: A Card Game of Duels 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: ** WARNING: iPad 2, iPad Mini 1 & iPhone 4S are NOT compatible. ** *** Special Launch Price for a limited... | Read more »

Price Scanner via MacPrices.net

Memorial Day savings: 13-inch Touch Bar MacBo...
B&H Photo has the 2016 Apple 13″ Touch Bar MacBook Pros in stock today and on sale for up to $150 off MSRP. Shipping is free, and B&H charges NY & NJ sales tax only: - 13″ 2.9GHz/512GB... Read more
Apple refurbished 13-inch MacBook Airs availa...
Apple has Certified Refurbished 2016 13″ MacBook Airs available starting at $849. An Apple one-year warranty is included with each MacBook, and shipping is free: - 13″ 1.6GHz/8GB/128GB MacBook Air: $... Read more
Apple restocks refurbished 11-inch MacBook Ai...
Apple has Certified Refurbished 11″ MacBook Airs (the latest models recently discontinued by Apple), available for up to $170 off original MSRP. An Apple one-year warranty is included with each... Read more
12-inch 1.2GHz Retina MacBooks on sale for up...
B&H has 12″ 1.2GHz Retina MacBooks on sale for up to $150 off MSRP. Shipping is free, and B&H charges NY & NJ sales tax only: - 12″ 1.2GHz Space Gray Retina MacBook: $1449.99 $150 off... Read more
15-inch 2.7GHz Silver Touch Bar MacBook Pro o...
MacMall has the 15-inch 2.7GHz Silver Touch Bar MacBook Pro (MLW82LL/A) on sale for $2569 as part of their Memorial Day sale. Shipping is free. Their price is $230 off MSRP. Read more
Free Tread Wisely Mobile App Endorsed By Fath...
Just in time for the summer driving season, Cooper Tire & Rubber Company has announced the launch of a new Tread Wisely mobile app. Designed to promote tire and vehicle safety among teens and... Read more
Commercial Notebooks And Detachable Tablets W...
Worldwide shipments of personal computing devices (PCDs), comprised of traditional PCs (a combination of desktop, notebook, and workstations) and tablets (slates and detachables), are forecast to... Read more
Best value this Memorial Day weekend: Touch B...
Apple has Certified Refurbished 2016 15″ and 13″ MacBook Pros available for $230 to $420 off original MSRP. An Apple one-year warranty is included with each model, and shipping is free: - 15″ 2.6GHz... Read more
13-inch MacBook Airs on sale for up to $130 o...
Overstock.com has 13″ MacBook Airs on sale for up to $130 off MSRP including free shipping: - 13″ 1.6GHz/128GB MacBook Air (sku MMGF2LL/A): $869.99 $130 off MSRP - 13″ 1.6GHz/256GB MacBook Air (sku... Read more
2.8GHz Mac mini available for $973 with free...
Adorama has the 2.8GHz Mac mini available for $973, $16 off MSRP, including a free copy of Apple’s 3-Year AppleCare Protection Plan. Shipping is free, and Adorama charges sales tax in NY & NJ... Read more

Jobs Board

*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Media Products - Commerce Engineerin...
Apple Media Products - Commerce Engineering Manager Job Number: 57037480 Santa Clara Valley, California, United States Posted: Apr. 18, 2017 Weekly Hours: 40.00 Job Read more
*Apple* Media Products - Commerce Engineerin...
Apple Media Products - Commerce Engineering Manager Job Number: 57037480 Santa Clara Valley, California, United States Posted: Apr. 18, 2017 Weekly Hours: 40.00 Job Read more
Best Buy *Apple* Computing Master - Best Bu...
**509643BR** **Job Title:** Best Buy Apple Computing Master **Location Number:** 001482- Apple Valley-Store **Job Description:** **What does a Best Buy Apple Read more
*Apple* Media Products - Commerce Engineerin...
Apple Media Products - Commerce Engineering Manager Job Number: 57037480 Santa Clara Valley, California, United States Posted: Apr. 18, 2017 Weekly Hours: 40.00 Job Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.