TweetFollow Us on Twitter

Creating Widgets with Dashcode �

Volume Number: 24 (2008)
Issue Number: 08
Column Tag: Dashboard Widgets

Creating Widgets with Dashcode

When to use Dashcode, and other important widget information

by Mihalis Tsoukalos

Introduction

This article is going to introduce you to Dashcode, an application -actually, an IDE- for creating and debugging Dashboard Widgets. You will also learn other essential information about installing and packaging Widgets, the Info.plist file and its keys as well as the Property List Editor.

What is Dashcode?

Dashcode is a development environment, a GUI application, for creating Widgets. Although it was exposed prior to its official release, we now know it is a reality. With the release of Mac OS X 10.5 and Xcode 3, Dashcode was officially released to end users.

You should use the Xcode Tools installer to install Dashcode. After installation, you will find Dashcode in /Developer/Applications/.

Figure 1 shows the About Dashcode window information of both the unofficial-this beta expired on July 15th, 2007-and official versions. Both versions are numbered as 1.0!


Figure 1: The "About Dashcode" information window of the unofficial and official Dashcode versions

When to use Dashcode

  • Dashcode is a great tool but it cannot solve every problem efficiently. Knowing its strengths and weaknesses will help you use it effectively. You can also judge when, and when not to use it.

  • Dashcode is wonderful for automatically creating template files that you can edit, as you wish, when creating your own Dashboard Widgets. This is a great time saver!

  • Dashcode is perfect for debugging Widgets because it allows you to dynamically view your errors. Another great time saver when troubleshooting Dashboard Widgets!

  • Dashcode is useful for quickly creating Info.plist files.

  • Dashcode is very efficient when creating Widget with localization.

When not to use Dashcode

I'll first admit a little bias: I personally do not, for the most part, like integrated programming environments, as I prefer to write my own code using my editor of choice. Although Dashcode came into action while I was writing my eBook, I was very happy that I wrote most of the book's code using an editor without using code that was automatically created by a tool. I dislike the fact that most programming environments style code as they prefer, where they prefer and, sometimes, without letting the programmer decide essential details.

My advice is that when you are learning a new programming paradigm or technique, it is generally better to first write all your code by hand, and, as you become more experienced, to use such a tool. Through exerience, you can differentiate good code from bad code, debug your code and make changes to the created code.

Also, although Dashcode allows the use of Widget plug-ins, it cannot create Widget plug-ins. You still need Xcode when programming Widget plug-ins.

If you create a Widget using Dashcode, your Widget will look similar to other Widgets created using Dashcode-so originality is not easily achieved.

How to package a Widget

Let us say that you have a minimal Widget, called HelloWorld-it just displays the "Hello World!" message inside Dashboard. This Widget only needs four files named HelloWorld.html, Info.plist, Default.png and Icon.png. The last three filenames are fixed, whereas the first one can be anything you want-provided that it is an HTML file-but its filename should be declared inside the Info.plist file.

So, you have your files and you want to actually "create and use" your Widget.

All you have to do now is put all the above files in the same directory. It is a good practice to use an explanatory directory name. I called mine HelloWorld. The next action is to go to the parent directory of the HelloWorld directory in order to rename it. The new name will be Helloworld.wdgt. A message asking you if you are sure about the new extension will appear and after answering yes you will get your first Widget ready for installation! The sign that you have successfully changed the directory type is that the directory icon will change.

Most of the time, it is good practice to have a copy of your Widgets as plain directories that contain the relevant files. It makes watching and changing the files easier as well as serving as a backup copy. Figure 2 shows the Command-I (using the Finder) information for a Widget bundle and the relevant plain directory structure, respectively.


Figure 2: The Cmd+I output for the HelloWorld.wdgt bundle and the HelloWorld directory

Installing a Widget

There are two places that you can install a Dashboard Widget. Also, there are two ways for installing a Widget.

The first place for installing a Widget is in the /Library/Widgets directory. The Widgets that are located there are system wide, which means that everyone in the same Tiger/Leopard system can use them. The second place is inside the Library/Widgets directory that is located in each user's home directory. Your home directory is usually called /Users/your_user_name.

The first way to install a Dashboard Widget is to double click on it. Mac OS X will ask you if you want to install it and if you answer "yes", it will put the Widget inside the Library/Widgets directory on your home directory. This directory is also called -given the shorthand notation- ~/Library/Widgets, with the tilde signifying your home directory in the UNIX jargon. This means that other users of the system cannot automatically use your Widget.

When double clicking a Widget, a message will ask you if you want to install it (this happens for security reasons). By pressing "Install", you will go inside Dashboard and see Figure 3.


Figure 3: Trying to install the HelloWorld! Widget

If you answer "Keep" the Widget is going to be installed inside your home directory ~/Library/Widgets. If you answer "Delete", the Widget is going to be placed in the Trash.

The second way is to manually copy the Widget bundle inside your preferred directory. You can still put in inside the Library/Widgets directory in your home directory (a.k.a. ~/Library/Widgets) but you can also install it manually in /Library/Widgets, provided that you have the required administrator privileges.

The Info.plist file and its keys

The Info.plist file is the property list file for every Dashboard Widget that is a XML file. Its filename is mandatory as well as its presence inside each Widget directory (or bundle if you prefer). The Info.plist file contains some keys, five of them being obligatory. Other keys may or may not be defined depending on the resources that are needed to be utilized by the Widget.

The mandatory property list keys are the following: CFBundleName, CFBundleDisplayName, CFBundleIdentifier, CFBundleVersion and MainHTML. All of them are of string type. The required properties are displayed in bold type in this list:

AllowFileAccessOutsideOfWidget: This key defines if the Widget is allowed to access the file system that is outside the Widget's directory. Access is limited by the permissions of the user that runs the Widget.

AllowFullAccess: This key defines if the Widget needs access to file system, Web Kit and standard browser plug-ins, Java applets, network resources, and command-line utilities.

AllowInternetPlugins: It defines if the Widget requires access to Web Kit and standard browser plug-ins.

AllowJava: It defines if the Dashboard Widget needs access to Java applets.

AllowNetworkAccess: This key defines if the Widget needs access to resources that are not file-based, including network resources.

AllowSystem: This key defines that the Widget requires access to command line tools using the Widget script object.

BackwardsCompatibleClassLookup: It defines if the Widget uses the JavaScript classes that are provided by Apple in a backward compatible way.

CloseBoxInsetX: It defines the offset for the location of the Dashboard Widget close box on the x-axis. Allowed values are between 0 and 100.

CloseBoxInsetY: It defines the offset for the location of the Dashboard Widget close box on the y-axis. Allowed values are between 0 and 100.

Font: It defines an array of strings. Each string denotes the name of a font that is located inside the Widget's root directory.

Height: It is an optional number that denotes the height of the Widget in pixels.

Width: It is an optional number that denotes the width of the Widget in pixels.

MainHTML: The relative path to the Widget's main HTML file. If this is wrong, chances are the Widget is not going to work at all!

CFBundleIdentifier: This is the "unique" name of the Widget. Apple's Widgets are named com.apple.widget._widgetname_ }. Other Widgets are named similarly.

CFBundleName: A string that defines the name of the Widget. The string must match the name of the Widget directory on disk without the .wdgt file extension.

CFBundleDisplayName: A string that defines the text that is going to be displayed in the Widget bar and the Finder.

CFBundleVersion: This is a String that defines the exact build version of the Widget.

Plugin: It is a string that defines the name of the custom plug-in that is used by the Widget. Plug-ins are located inside the Widget's directory and are compiled Objective-C code.

The list is big but, as you already know, only five property list keys are mandatory. Most of them are optional, depending on what your Widget is planning to do. It is a very important task to define them the right way-both for security and functionality reasons.

It is important to remember that if your Widget does not work as expected or does not even show on Dashboard, the first thing to look is if the required property list keys are properly and correctly defined. It is a common mistake that can cause a lot of lost time in debugging.

The Property List Editor

The Property List Editor is for creating, altering and viewing an Info.plist file (and other .plist files) which is a plain text file in XML format. The main difference from a text editor like vi, emacs, or nano is that Property List Editor is a GUI application-some people find it easier and less error prone to use a GUI application than a traditional text editor. On the other hand, plain text editing is quicker and can be automated using a scripting language.

Be careful with the editor you use, as not every application saves in a plain text format. Be aware of software such as Microsoft Word for Mac or Macromedia (now Adobe) Dreamweaver to create a pure text file.

First, let me present you an example Info.plist file in XML format:

   <?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>AllowSystem</key>
       <true/>
       <key>CFBundleDisplayName</key>
       <string>MakeTar</string>
       <key>CFBundleIdentifier</key>
       <string>com.mtsouk.widget.maketar</string>
       <key>CFBundleName</key>
       <string>Make Tar Widget</string>
       <key>CFBundleShortVersionString</key>
       <string>1.1</string>
       <key>CFBundleVersion</key>
       <string>1.1</string>
       <key>CloseBoxInsetX</key>
       <integer>45</integer>
       <key>CloseBoxInsetY</key>
       <integer>35</integer>
       <key>MainHTML</key>
       <string>MakeTar.html</string>
   </dict>
   </plist>

The same Info.plist file in Property List Editor can be seen in Figure 4.


Figure 4: A Property List Editor example

Apart from the preamble of the Info.plist file, which is hidden in Property List Editor, the rest of the information is easy to be seen or altered. If you press the "Dump" button in the upper right corner, you will get the Info.plist in plain text format, including the preamble.

If you ask my opinion, I prefer the plain text version of the Info.plist file :-) I rarely use the Property List Editor.

A Dashcode example

This part of the article will present you with a brief Dashcode example. I am going to create a complete Widget, for illustrating the Dashcode usage. In a previous article, I created a Widget that reads the RSS feed from MacTech.com and displays it in a Widget. I decided to create the same Widget using Dashcode. Please note that there is an existing RSS feed Widget template inside Dashcode that greatly simplifies the process.

Figure 4 shows the look of the Widget created in Dashcode. You can also dynamically change the length of the presented articles (using the backside of the Widget)-I should say that I am pretty impressed as it only took me 10 minutes to create it! It is also impressive that I did not write a single line of code!


Figure 5: A Widget that reads RSS feed from MacTech.com

When launched, Dashcode presents a theme chooser. There are two RSS feed types: a generic RSS list type, and a "Daily Feed" template. The "Daily Feed" template shows only the current item from the RSS feed. I chose the "RSS" template for this example (see below).


Apple's available Widget templates

Once chosen, Dashcode displays the main window with a graphical representation of the widget showing. By choosing "Widget Attributes" in the navigation bar on the left of the window, you can access and edit all properties of the widget. Figure 6 shows this screen, including the source for the RSS feed as well as some of the keys in the Info.plist file, the Widget identifier, its version number, etc. You can even add localization to your Widget.


Figure 6: Setting attributes from within Dashcode

For more complex widgets, or just for a little hand-holding, you can also follow the "Workflow Steps" portion of the window to step through the process. If an attribute is required, Dashcode lets you know with a "Required" badge.


For the RSS widget, only two attributes are required: the Identifier, and feed property. The identifier differentiates one widget from another. Typically, identifiers are specified in reverse domain notation.


In this example, the identifier is com.mtsouk.widget.sampleRSS. The version number helps Dashboard to determine if you're running the latest version of a widget. The identifier and version fields correspond to the CFBundleIdentifer and CFBundleVersion in the widget's Info.plist file.

The other required property is the FeedURL and respective feed information.


Then, by going to the File menu and selecting "Deploy Widget" (figure 10), you can export your Widget and have it as a separate object that you can distribute and install. After installing the Widget in Dashboard, it worked without problems.


Figure 10: Deploying a Widget from Dashcode

I will also show you the list of the files that Dashcode creates at the root of the widget package using the UNIX ls -al command:

mtsouk$ ls -al
.:
total 64
drwxr-xr-x  13 mtsouk  staff    442 Apr  7 17:36 .
drwxr-xr-x  24 mtsouk  staff    816 Apr  7 17:36 ..
-rw-r—r—   1 mtsouk  staff   4329 Apr  7 17:07 Default.png
-rw-rw-r—   1 mtsouk  staff   1196 Sep 24  2007 Icon.png
drwxr-xr-x  14 mtsouk  staff    476 Apr  7 17:04 Images
-rw-rw-r—   1 mtsouk  staff    832 Apr  7 17:36 Info.plist
drwxr-xr-x   9 mtsouk  staff    306 Apr  7 17:04 Parts
-rw-rw-r—   1 mtsouk  staff   1840 Sep 24  2007 SafariStyle.css
-rw-rw-r—   1 mtsouk  staff   4084 Apr  7 17:07 SampleRSS.css
-rw-rw-r—   1 mtsouk  staff   3015 Apr  7 17:36 SampleRSS.html
-rw-rw-r—   1 mtsouk  staff  31187 Apr  7 17:04 SampleRSS.js
-rw-rw-r—   1 mtsouk  staff    295 Apr  7 17:24 attributes.js
drwxr-xr-x   4 mtsouk  staff    136 Apr  7 17:08 en.lproj

True to my preference for hand coded widgets, I'll point out that the Widget I created for processing the MacTech.com RSS feed for the previous article is a little bit smaller in size.

Conclusions

Creating Dashboard Widgets is easy provided that you know some basic things and follow some principles. Apple provides many tools that will help you write Widgets. One of them, Dashcode, is a handy tool provided that you can understand its strengths and weaknesses. If you are an intermediate to experienced Widget programmer then it can save you time. If you are just starting Dashboard Widget programming then I would propose that you start programming Widgets without using Dashcode to truly learn the foundations of what goes into a widget.

Bibliography and References

http://developer.apple.com/

http://developer.apple.com/tools/dashcode/

http://www.apple.com/macosx/developertools/dashcode.html

Introducing Dashcode: http://developer.apple.com/leopard/overview/dashcode.html

Wikipedia Dashcode entry: http://en.wikipedia.org/wiki/Dashcode


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

Microsoft Remote Desktop 8.0.16 - Connec...
With Microsoft Remote Desktop, you can connect to a remote PC and your work resources from almost anywhere. Experience the power of Windows with RemoteFX in a Remote Desktop client designed to help... Read more
Spotify 1.0.4.90. - Stream music, create...
Spotify is a streaming music service that gives you on-demand access to millions of songs. Whether you like driving rock, silky R&B, or grandiose classical music, Spotify's massive catalogue puts... Read more
djay Pro 1.1 - Transform your Mac into a...
djay Pro provides a complete toolkit for performing DJs. Its unique modern interface is built around a sophisticated integration with iTunes and Spotify, giving you instant access to millions of... Read more
Vivaldi 1.0.118.19 - Lightweight browser...
Vivaldi browser. In 1994, two programmers started working on a web browser. Our idea was to make a really fast browser, capable of running on limited hardware, keeping in mind that users are... Read more
Stacks 2.6.11 - New way to create pages...
Stacks is a new way to create pages in RapidWeaver. It's a plugin designed to combine drag-and-drop simplicity with the power of fluid layout. Features: Fluid Layout: Stacks lets you build pages... Read more
xScope 4.1.3 - Onscreen graphic measurem...
xScope is powerful set of tools that are ideal for measuring, inspecting, and testing on-screen graphics and layouts. Its tools float above your desktop windows and can be accessed via a toolbar,... Read more
Cyberduck 4.7 - FTP and SFTP browser. (F...
Cyberduck is a robust FTP/FTP-TLS/SFTP browser for the Mac whose lack of visual clutter and cleverly intuitive features make it easy to use. Support for external editors and system technologies such... Read more
Labels & Addresses 1.7 - Powerful la...
Labels & Addresses is a home and office tool for printing all sorts of labels, envelopes, inventory labels, and price tags. Merge-printing capability makes the program a great tool for holiday... Read more
teleport 1.2.1 - Use one mouse/keyboard...
teleport is a simple utility to let you use one single mouse and keyboard to control several of your Macs. Simply reach the edge of your screen, and your mouse teleports to your other Mac! The... Read more
Apple iMovie 10.0.8 - Edit personal vide...
With an all-new design, Apple iMovie lets you enjoy your videos like never before. Browse your clips more easily, instantly share your favorite moments, and create beautiful HD movies and Hollywood-... Read more

Use Batting Average and the Apple Watch...
Batting Average, by Pixolini, is designed to help you manage your statistics. Every time you go to bat, you can use your Apple Watch to track  your swings, strikes, and hits. [Read more] | Read more »
Celebrate Studio Pango's 3rd Annive...
It is time to party, Pangoland pals! Studio Pango is celebrating their 3rd birthday and their gift to you is a new update to Pangoland. [Read more] | Read more »
Become the World's Most Important D...
Must Deliver, by cherrypick games, is a top-down endless-runner witha healthy dose of the living dead. [Read more] | Read more »
SoundHound + LiveLyrics is Making its De...
SoundHound Inc. has announced that SoundHound + LiveLyrics, will be one of the first third-party apps to hit the Apple Watch. With  SoundHound you'll be able to tap on your watch and have the app recognize the music you are listening to, then have... | Read more »
Adobe Joins the Apple Watch Lineup With...
A whole tidal wave of apps are headed for the Apple Watch, and Adobe has joined in with 3 new ways to enhance your creativity and collaborate with others. The watch apps pair with iPad/iPhone apps to give you total control over your Adobe projects... | Read more »
Z Steel Soldiers, Sequel to Kavcom'...
Kavcom has released Z Steel Soldiers, which continues the story of the comedic RTS originally created by the Bitmap Brothers. [Read more] | Read more »
Seene Lets You Create 3D Images With You...
Seene, by Obvious Engineering, is a 3D capture app that's meant to allow you to create visually stunning 3D images with a tap of your finger, and then share them as a 3D photo, video or gif. [Read more] | Read more »
Lost Within - Tips, Tricks, and Strategi...
Have you just downloaded Lost Within and are you in need of a guiding hand? While it’s not the toughest of games out there you might still want some helpful tips to get you started. [Read more] | Read more »
Entertain Your Pet With Your Watch With...
The Petcube Camera is a device that lets you use live video to check in on your pet, talk to them, and play with them using a laser pointer - all while you're away. And the Petcube app is coming to the Apple Watch, so you'll be able to hang out with... | Read more »
Now You Can Manage Your Line2 Calls With...
You'll be able to get your Line2 cloud phone service on the Apple Watch very soon. The watch app can send and receive messages using hands-free voice dictation, or by selecting from a list of provided responses. [Read more] | Read more »

Price Scanner via MacPrices.net

Intel Compute Stick: A New Mini-Computing For...
The Intel Compute Stick, a new pocket-sized computer based on a quad-core Intel Atom processor running Windows 8.1 with Bing, is available now through Intel Authorized Dealers across much of the... Read more
Heal to Launch First One-Touch House Call Doc...
Santa Monica, California based Heal, a pioneer in on-demand personal health care services — will offer the first one-touch, on-demand house call doctor app for the Apple Watch. Heal’s Watch app,... Read more
Mac Notebooks: Avoiding MagSafe Power Adapter...
Apple Support says proper usage, care, and maintenance of Your Mac notebook’s MagSafe power adapter can substantially increase the the adapter’s service life. Of course, MagSafe itself is an Apple... Read more
12″ Retina MacBook In Shootout With Air And P...
BareFeats’ rob-ART morgan has posted another comparison of the 12″ MacBook with other Mac laptops, noting that the general goodness of all Mac laptops can make which one to purchase a tough decision... Read more
FileMaker Go for iPad and iPhone: Over 1.5 Mi...
FileMaker has announced that its FileMaker Go for iPad and iPhone app has surpassed 1.5 million downloads from the iTunes App Store. The milestone confirms the continued popularity of the FileMaker... Read more
Sale! 13-inch 2.7GHz Retina MacBook Pro for $...
 Best Buy has the new 2015 13″ 2.7GHz/128GB Retina MacBook Pro on sale for $1099 – $200 off MSRP. Choose free shipping or free local store pickup (if available). Price for online orders only, in-... Read more
Minimalist MacBook Confirms Death of Steve Jo...
ReadWrite’s Adriana Lee has posted a eulogy for the “Digital Hub” concept Steve Jobs first proposed back in 2001, declaring the new 12-inch MacBook with its single, over-subscribed USB-C port to be... Read more
13-inch 2.7GHz Retina MacBook Pro for $1234 w...
Adorama has the 13″ 2.7GHz/128GB Retina MacBook Pro in stock for $1234.99 ($65 off MSRP) including free shipping plus a free LG external DVD/CD optical drive. Adorama charges sales tax in NY & NJ... Read more
13-inch 2.5GHz MacBook Pro available for $999...
 Adorama has the 13-inch 2.5GHz MacBook Pro on sale for $999 including free shipping plus NY & NJ sales tax only. Their price is $100 off MSRP. Read more
Save up to $600 with Apple refurbished Mac Pr...
The Apple Store is offering Apple Certified Refurbished Mac Pros for up to $600 off the cost of new models. An Apple one-year warranty is included with each Mac Pro, and shipping is free. The... Read more

Jobs Board

*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Support Technician IV - Jack Henry a...
Job Description Jack Henry & Associates is seeking an Apple Support Technician. This position while acting independently, ensures the proper day-to-day control of Read more
*Apple* Client Systems Solution Specialist -...
…drive revenue and profit in assigned sales segment and/or region specific to the Apple brand and product sets. This person will work directly with CDW Account Managers Read more
*Apple* Software Support - Casper (Can work...
…experience . Full knowledge of Mac OS X and prior . Mac OSX / Server . Apple Remote Desktop . Process Documentation . Ability to prioritize multiple tasks in a fast pace Read more
*Apple* Software Support - Xerox Corporation...
…Imaging experience Full knowledge of Mac OS X and prior Mac OSX / Server Apple Remote Desktop Process Documentation Ability to prioritize multiple tasks in a fast pace Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.