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

Dashlane 6.2027.0 - Password manager and...
Dashlane is an award-winning service that revolutionizes the online experience by replacing the drudgery of everyday transactional processes with convenient, automated simplicity - in other words,... Read more
ffWorks 2.1.5 - Convert multimedia files...
ffWorks, focused on simplicity, brings a fresh approach to the use of FFmpeg, allowing you to create ultra-high-quality movies without the need to write a single line of code on the command-line.... Read more
Dropbox 101.4.434 - Cloud backup and syn...
Dropbox for Mac is a file hosting service that provides cloud storage, file synchronization, personal cloud, and client software. It is a modern workspace that allows you to get to all of your files... Read more
1Password 7.6 - Powerful password manage...
1Password is a password manager that uniquely brings you both security and convenience. It is the only program that provides anti-phishing protection and goes beyond password management by adding Web... Read more
EyeTV 4.0.0 - Watch and record TV on you...
EyeTV brings a rich TV experience to your Mac. Watch live TV on your Mac. Pause, rewind, and record whenever you want. EyeTV gives you powerful control over what you watch and how you watch it. Put... Read more
Tidy Up 5.3.7 - Find duplicate files and...
Tidy Up is a full-featured duplicate finder and disk-tidiness utility. Features: Supports Lightroom: it is now possible to search and collect duplicates directly in the Lightroom library. Multiple... Read more
Pinegrow 5.97 - Mockup and design web pa...
Pinegrow (was Pinegrow Web Designer) is desktop app that lets you mockup and design webpages faster with multi-page editing, CSS and LESS styling, and smart components for Bootstrap, Foundation,... Read more
BlueStacks 4.210.0 - Run Android applica...
BlueStacks App Player lets you run your Android apps fast and fullscreen on your Mac. Feature comparison chart How to install Bluestacks on your Mac Go to MacUpdate and click the green "Download"... Read more
WhatsApp 2.2027.10 - Desktop client for...
WhatsApp is the desktop client for WhatsApp Messenger, a cross-platform mobile messaging app which allows you to exchange messages without having to pay for SMS. WhatsApp Messenger is available for... Read more
Art Text 4.0.1 - $29.99
Art Text is graphic design software specifically tuned for lettering, typography, text mockups and various artistic text effects. Supplied with a great variety of ready to use styles and materials,... Read more

Latest Forum Discussions

See All

Marvel Super War launches its third seas...
Marvel Super War, NetEase's popular MOBA, has kicked off its third season today, introducing its Zone Invasion beta and an all-new playable superhero. [Read more] | Read more »
Brave Dungeon, Unlock Games' idle-R...
Brave Dungeon, Unlock Games' idle-RPG and auto chess title, has been downloaded over 1 million times since it launched last week. To commemorate reaching this milestone the developers have decided to host a series of in-game events. [Read more] | Read more »
Clash Royale: The Road to Legendary Aren...
Supercell recently celebrated its 10th anniversary and their best title, Clash Royale, is as good as it's ever been. Even for lapsed players, returning to the game is as easy as can be. If you want to join us in picking the game back up, we've put... | Read more »
Steam Link Spotlight - Disco Elysium
Steam Link Spotlight is a feature where we look at PC games that play exceptionally well using the Steam Link app. Our last entry was Signs of the Sojourner Read about how it plays using Steam Link over here. | Read more »
Distract Yourself With These Great Mobil...
There’s a lot going on right now, and I don’t really feel like trying to write some kind of pithy intro for it. All I’ll say is lots of people have been coming together and helping each other in small ways, and I’m choosing to focus on that as I... | Read more »
Pokemon Go's July Community Day wil...
Pokemon Go developers have announced the details concerning the upcoming Gastly Community Day. This particular event was selected by the players of the game after the Gas Pokemon came in second place after a poll that decided which Pokemon would... | Read more »
Clash Royale: The Road to Legendary Aren...
Supercell recently celebrated its 10th anniversary and their best title, Clash Royale, is as good as it's ever been. Even for lapsed players, returning to the game is as easy as can be. If you want to join us in picking the game back up, we've put... | Read more »
Detective Di is a point-and-click murder...
Detective Di is a point-and-click murder mystery set in Tang Dynasty-era China. You'll take on the role of China's best-known investigator, Di Renjie, as he solves a series of grisly murders that will ultimately lead him on a collision course with... | Read more »
Dissidia Final Fantasy Opera Omnia is se...
Dissidia Final Fantasy Opera Omnia, one of Square Enix's many popular mobile RPGs, has announced a plethora of in-game events that are set to take place over the summer. This will include several rewards, Free Multi Draws and more. [Read more] | Read more »
Sphaze is a neat-looking puzzler where y...
Sphaze is a neat-looking puzzler where you'll work to guide robots through increasingly elaborate mazes. It's set in a visually distinct world that's equal parts fantasy and sci-fi, and it's finally launched today for iOS and Android devices. [... | Read more »

Price Scanner via MacPrices.net

B&H Photo offers $200-$300 discounts on A...
B&H Photo has new 16″ MacBook Pros on sale today for $200-$300 off Apple’s MSRP, starting at $2149. Expedited shipping is free to many addresses in the US: – 2019 16″ 2.6GHz 6-Core MacBook Pro... Read more
Clearance 2019 15″ MacBook Pros on sale today...
Amazon-owned Woot is blowing out Apple refurbished, clearance 2019 15″ MacBook Pros starting at only $1579 and up to $950 off Apple’s original MSRP. According to Woot, “These MacBooks are Refurbished... Read more
Apple Refurbished iMac Pros available for $35...
Amazon-owned Woot is selling Apple refurbished 27″ 3.2GHz 8-Core iMac Pros for $3599.99 shipped. That’s $1400 off Apple’s original MSRP for this model. According to Woot, these iMac Pros are “Factory... Read more
Clearance 2019 13″ 2.4GHz/256GB MacBook Pro o...
B&H Photo has dropped their price on the clearance 2019 13″ 2.4GHz/256GB Quad-Core Silver MacBook Pro by $500 off Apple’s original MSRP to a new low of only $1299. Expedited shipping is free to... Read more
$219 Apple AirPods Pro are back at Verizon, s...
Verizon has Apple AirPods Pro on sale again for a limited time for $219.99 on their online store. Their price is $30 off Apple’s MSRP, and it’s the lowest price we’ve seen for AirPods Pro. Available... Read more
Apple’s $779 13″ MacBook Air deal returns to...
Apple has clearance, Certified Refurbished, 2019 13″ MacBook Airs available again starting at $779. Each MacBook features a new outer case, comes with a standard Apple one-year warranty, and is... Read more
$200 13″ MacBook Pro discounts are back at Am...
Amazon has 2020 13″ 2.0GHz MacBook Pros on sale again today for $150-$200 off Apple’s MSRP. Shipping is free. Be sure to purchase the MacBook Pro from Amazon, rather than a third-party seller, and... Read more
Deal Alert! Apple AirPods with Wireless Charg...
Sams Club has Apple AirPods with Wireless Charging Case on sale on their online store for only $149.98 from July 6, 2020 to July 9, 2020. Their price is $50 off Apple’s MSRP, and it’s the lowest... Read more
Xfinity Mobile promo: Apple iPhone XS models...
Take $300 off the purchase of any Apple iPhone XS model at Xfinity Mobile while supplies last. Service plan required: – 64GB iPhone XS: $599.99 save $300 – 256GB iPhone XS: $749.99 save $300 – 512GB... Read more
New July 2020 promo at US Cellular: Switch an...
US Cellular has introduced a new July 2020 deal offering free 64GB Apple iPhone 11 smartphones to customers opening a new line of service. No trade-in required, and discounts are applied via monthly... Read more

Jobs Board

Product Manager, *Apple* Commercial Sales -...
Product Manager, Apple Commercial Sales Austin, TX, US Requisition Number:77652 As an Apple Product Manager for the Commercial Sales team at Insight, you Read more
Physical Therapist Assistant - *Apple* Hill...
Physical Therapist Assistant - Apple Hill Rehab - Full Time Tracking Code 62519 Job Description General Summary: Under the direct supervision of a licensed Physical Read more
Operating Room Assistant, *Apple* Hill Surg...
Operating Room Assistant, Apple Hill Surgical Center - Full Time, Day Shift, Monday - Saturday availability required Tracking Code 62363 Job Description Operating Read more
Perioperative RN - ( *Apple* Hill Surgical C...
Perioperative RN - ( Apple Hill Surgical Center) Tracking Code 60593 Job Description Monday - Friday - Full Time Days Possible Saturdays General Summary: Under the Read more
Product Manager, *Apple* Commercial Sales -...
Product Manager, Apple Commercial Sales Austin, TX, US Requisition Number:77652 As an Apple Product Manager for the Commercial Sales team at Insight, you Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.