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

DiskCatalogMaker 7.1.3 - Catalog your di...
DiskCatalogMaker is a simple disk management tool which catalogs disks. Simple, light-weight, and fast Finder-like intuitive look and feel Super-fast search algorithm Can compress catalog data for... Read more
Together 3.8.7 - Store and organize all...
Together helps you organize your Mac, giving you the ability to store, edit and preview your files in a single clean, uncluttered interface. Together Features Smart storage. With simple drag-and-... Read more
Little Snitch 4.0.1 - Alerts you about o...
Little Snitch gives you control over your private outgoing data. Track background activity As soon as your computer connects to the Internet, applications often have permission to send any... Read more
Sparkle Pro 2.2.1 - $79.99
Sparkle Pro will change your mind if you thought building websites wasn't for you. Sparkle is the intuitive site builder that lets you create sites for your online portfolio, team or band pages, or... Read more
iWatermark Pro 2.0.0fc4 - Easily add wat...
iWatermark Pro is the essential watermarking app for professional, business, and personal use. Easily secure and protect your photos with text, a graphic, a signature, or a QR watermark. Once added... Read more
Amadeus Pro 2.4 - Multitrack sound recor...
Amadeus Pro lets you use your Mac for any audio-related task, such as live audio recording, digitizing tapes and records, converting between a variety of sound formats, etc. Thanks to its outstanding... Read more
iFFmpeg 6.4.2 - Convert multimedia files...
iFFmpeg is a comprehensive media tool to convert movie, audio and media files between formats. The FFmpeg command line instructions can be very hard to master/understand, so iFFmpeg does all the hard... Read more
EtreCheck 3.4.2 - 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
Carbon Copy Cloner 4.1.17 - Easy-to-use...
Carbon Copy Cloner backups are better than ordinary backups. Suppose the unthinkable happens while you're under deadline to finish a project: your Mac is unresponsive and all you hear is an ominous,... Read more
VueScan 9.5.81 - Scanner software with a...
VueScan is a scanning program that works with most high-quality flatbed and film scanners to produce scans that have excellent color fidelity and color balance. VueScan is easy to use, and has... Read more

Latest Forum Discussions

See All

Eden: Renaissance (Games)
Eden: Renaissance 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: Eden: Renaissance is a thrilling turn-based puzzle adventure set in a luxurious world, offering a deep and moving... | Read more »
Glyph Quest Chronicles guide - how to ma...
Glyph Quest returns with a new free-to-play game, Glyph Quest Chronicles. Chronicles offers up more of the light-hearted, good humored fantasy fun that previous games featured, but with a few more refined tricks up its sleeve. It's a clever mix of... | Read more »
Catch yourself a Lugia and Articuno in P...
Pokémon Go Fest may have been a bit of a disaster, with Niantic offering fans full refunds and $100 worth of in-game curency to apologize for the failed event, but that hasn't ruined trainers' chances of catching new legendary Pokémon. Lugia nad... | Read more »
The best deals on the App Store this wee...
There are quite a few truly superb games on sale on the App Store this week. If you haven't played some of these, many of which are true classics, now's the time to jump on the bandwagon. Here are the deals you need to know about. [Read more] | Read more »
Realpolitiks Mobile (Games)
Realpolitiks Mobile 1.0 Device: iOS Universal Category: Games Price: $5.99, Version: 1.0 (iTunes) Description: PLEASE NOTE: The game might not work properly on discontinued 1GB of RAM devices (iPhone 5s, iPhone 6, iPhone 6 Plus, iPad... | Read more »
Layton’s Mystery Journey (Games)
Layton’s Mystery Journey 1.0.0 Device: iOS Universal Category: Games Price: $15.99, Version: 1.0.0 (iTunes) Description: THE MUCH-LOVED LAYTON SERIES IS BACK WITH A 10TH ANNIVERSARY INSTALLMENT! Developed by LEVEL-5, LAYTON’S... | Read more »
Full Throttle Remastered (Games)
Full Throttle Remastered 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: Originally released by LucasArts in 1995, Full Throttle is a classic graphic adventure game from industry legend Tim... | Read more »
Stunning shooter Morphite gets a new tra...
Morphite is officially landing on iOS in September. The game looks like the space shooter we've been needing on mobile, and we're going to see if it fits the bill quite shortly. The game's a collaborative effort between Blowfish Studios, We're Five... | Read more »
Layton's Mystery Journey arrives to...
As you might recall, Layton's Mystery Journey is headed to iOS and Android -- tomorrow! To celebrate the impending launch, Level-5's released a new trailer, complete with an adorable hamster. [Read more] | Read more »
Sidewords (Games)
Sidewords 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Grab a cup of coffee and relax with Sidewords. Sidewords is part logic puzzle, part word game, all original. No timers. No... | Read more »

Price Scanner via MacPrices.net

PHOOZY World’s First Thermal Capsules to Summ...
Summer days spent soaking up the sun can be tough on smartphones, causing higher battery consumption and overheating. To solve this problem, eXclaim IP, LLC has introduced the PHOOZY Thermal Capsule... Read more
2018 Honda Ridgeline with Android Auto and Ap...
The 2018 Honda Ridgeline is arriving in dealerships nationwide with a Manufacturer’s Suggested Retail Price (MSRP1) starting at $29,630. The 2017 Honda Ridgeline was named North American Truck of the... Read more
comScore Ranks Top 15 U.S. Smartphone Apps fo...
comScore, Inc. recently released data from comScore Mobile Metrix, reporting the top smartphone apps in the U.S. by audience reach for June 2017. * “Apple Music,” as it appears in comScore’s monthly... Read more
13-inch 3.1GHz MacBook Pros on sale for $100...
B&H Photo has the new 2017 13″ 3.1GHz Space Gray MacBook Pros in stock today and on sale for $100 off MSRP including free shipping. B&H charges sales tax in NY and NJ only: – 13″ 3.1GHz/256GB... Read more
Apple refurbished Mac minis available startin...
Apple has Certified Refurbished Mac minis available starting at $419. Apple’s one-year warranty is included with each mini, and shipping is free: – 1.4GHz Mac mini: $419 $80 off MSRP – 2.6GHz Mac... Read more
Apple’s 2017 Back to School Promotion: Free B...
Purchase a new Mac using Apple’s Education discount, and take up to $300 off MSRP. All teachers, students, and staff of any educational institution qualify for the discount. Shipping is free. As part... Read more
Clearance 2016 13-inch MacBook Pros available...
B&H Photo has clearance 2016 13″ MacBook Pros in stock today for up to $220 off original MSRP. Shipping is free, and B&H charges NY & NJ sales tax only: – 13″ 2.9GHz/512GB Touch Bar... Read more
Apple Move Away from White Label Event Apps C...
DoubleDutch, Inc., a global provider of Live Engagement Marketing (LEM) solutions, has made a statement in the light of a game-changing announcement from Apple at this year’s WWDC conference.... Read more
70 Year Old Artist Creates Art Tools for the...
New Hampshire-based developer Pirate’s Moon has announced MyArtTools 1.1.3, the update to their precision drawing app, designed by artist Richard Hoeper exclusively for use with the 12.9-inch iPad... Read more
Sale! New 2017 13-inch 2.3GHz MacBook Pros fo...
Amazon has new 2017 13″ 2.3GHz/128GB MacBook Pros on sale today for $150 off MSRP including free shipping. Their prices are the lowest available for these models from any reseller: – 13″ 2.3GHz/128GB... Read more

Jobs Board

*Apple* Solutions Consultant (ASC) - Poole -...
Job Summary The people here at Apple don't just create products - they create the kind of wonder that's revolutionised entire industries. It's the diversity of those Read more
SW Engineer *Apple* TV - Apple Inc. (United...
Changing the world is all in a day's work at Apple . If you love innovation, here's your chance to make a career of it. You'll work hard. But the job comes with more Read more
Frameworks Engineering Manager, *Apple* Wat...
Frameworks Engineering Manager, Apple Watch Job Number: 41632321 Santa Clara Valley, California, United States Posted: Jun. 15, 2017 Weekly Hours: 40.00 Job Summary Read more
Product Manager - *Apple* Pay on the *Appl...
Job Summary Apple is looking for a talented product manager to drive the expansion of Apple Pay on the Apple Online Store. This position includes a unique Read more
*Apple* Retail - Multiple Positions - Apple...
SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.