Debugging Titanium Applications using Safari Web Inspector
Debugging is one of the most frustrating aspects of software development of any kind – it is also one of the most essential. Finding a malfunction can be time consuming; therefore, it is important to have effective tools that can decrease your debugging time. For Titanium, most of my debugging consisted of log statements and alerts. While this method can be useful, it can also be a little time consuming to rebuild and to log a different variable, collection or model.
One of my coworkers saw me using this log for debugging and suggested an alternative: using Safari Web Inspector. I was very surprised at how easy it was to set up and how effective it can be throughout the process. This one line is all you need to add to your “tiapp.xml” file in your project:
under the <iOS> flag. Unfortunately, this method only works on an iOS simulator. Once you have updated your tiapp.xml, build your project and navigate to the page you would like to inspect. Next you will need to open Safari; if the develop tab isn’t visible you will need to follow a couple extra steps:
Select the Safari tab from that dropdown navigate to preferences then check “Show develop menu in bar.” After the Develop tab is visible you will open the Simulator option and then select JSContext.
This is where all the magic happens. The files where breakpoints can be inserted will be visible on the left panel of the screen. Breakpoints are very convenient for stepping through your code and seeing exactly what is happening. I suggest opening the right panel when the breakpoints are hit. This is where you will find local variables and can also add Watch Expressions. Watch Expressions is the place where you can add the variables that you would like to keep an eye on. You will be able to see and follow each variable through every step of your code.
The bottom console is also a very helpful aspect of this debugger. I use this for taking a look at any model or collection to inspect in detail what they contain. This has been a lifesaver for me. It makes it easy to investigate exactly what is going on with any unexpected behavior with your models or collections.
The safari web inspector has it’s problems and will, from time to time, crash the app – but overall this tool has helped me immensely debugging my titanium apps. It makes it so effortless to nail down exactly where the problem lies. As much as we all want to have flawless code without bugs, they will appear every once in awhile. However, this tool can save you from the frustration those bugs can cause. As I stated before, it is very easy to set up, so jump in and play around with it a bit. Have any questions or comments? Feel free to share your your tricks for debugging. Also, you can find our latest apps and check out our work here.
Editor: In case you need to know other ways we used to debug Titanium Apps, please also check Appcelerator Titanium iOS Debugging with XCode or Rapid Titanium WebView debugging with Chrome Developer Tools