Surfin' Safari

Introducing Drosera

Posted by Timothy Hatcher on Wednesday, June 28th, 2006 at 12:35 am

Drosera JavaScript DebuggerI would like to introduce a new addition to the WebKit open source tools—a JavaScript debugger. Drosera, named after the largest genera of bug eating plants, lets you attach and debug JavaScript for any WebKit application—not just Safari.

One of the unique things about Drosera, like the Web Inspector, is that over 90% of it is written in HTML and JavaScript. This is a true testament of what you can do with web technologies today and the rapid development that WebKit allows.

So update your tree or download the nightly and give Drosera a try. The nightly always has JavaScript debugging enabled, you just need to attach from Drosera. However, to attach to Safari with your own WebKit build you will need to type the following once in the Terminal:

defaults write \
WebKitScriptDebuggerEnabled -bool true

To debug your application’s JavaScript you will need to enable this default for your application’s bundle identifier. Additionaly you need to launch your application using the TOT WebKit frameworks. You can easily do this with the run-webkit-app script inside WebKitTools/Scripts, then you will see your application show up in Drosera’s attach window.

Our bugzilla now has a Drosera component, so please feel free to file any bugs, enhancement requests and especially patches!

64 Responses to “Introducing Drosera”

  1. chrisholland Says:

    AWESOME! someone digg this :)

  2. xenon Says:

    Already done.

  3. aneumann Says:

    This javascript debugger could be very useful for me. Thanks for providing!

    I have a problem though (maybe I am just misunderstanding the concept, maybe it is a bug).

    If you open a SVG file, lets say (thats a pretty simple file) and attach Drosera to webkit and reload the file it correctly loads the inline ecmascript sourcecode. I can correctly set breakpoints, but when I execute the script, (lets say by clicking on ‘Click on this text to create a new rectangle’) I can only see the function name ‘createRect()’ but the debugger doesn’t change to the code view of the function ‘createRect()’. It seems to stop at breakpoints and works with “Continue”, but without seeing the code and having the ability to add variables to watch I cannot use it.

    Is this a bug or am I doing something wrong?

    Thanks for any help on that,

  4. google636 Says:

    Thank you so much!
    I can’t wait until all these new features make their way into the public Safari builds. It will be such a help for all us web developers and designers!

  5. jhurshman Says:

    I am very excited about this tool, but I am afraid I cannot figure out how to access it. I have downloaded the nightly, but I don’t see “Drosera” anywhere on the menus. (Also, I thought the nightly used to show “420+” as the build number, but now it’s showing “419.3”.)

    Sorry for the lack of clue.

  6. jhurshman Says:

    OK, the WebKit version test at is showing 420+, so I guess that’s fine.

  7. google636 Says:

    jhurshman – 
    Take the apps (Drosera and Webkit) off the dik image, then launch drosera. 
    File > Attatch…
    Select Webkit, then click attatch. The debugger will come up.

  8. jhurshman Says:

    I see. Drosera an additional application. I use NightShift to get the latest nightly and didn’t realize I was missing something.


  9. Pingback from Painfully Obvious » Blog Archive » Link: Drosera:

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  10. ccapeng Says:

    Generally in my daily development, safari js/dhtml give me more troube. Hope, this tool can give me good help.

    Not sure anyhing new in Safari 2.0.4. But, please release new js engine and don’t wait for next OS X(10.5). This will make all web developers happy.

  11. Pingback from Information Technology » WebKit adds a JavaScript Debugger:

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  12. Trackback from Ajaxian:

    Safari get a Javascript debugger

    Its about time – Webkit – the development version of Safari, has gotten a real javascript debugger. Its called Drosera, and the Surfin Safari blog has the announcement. Or you can just download the latest nightly of Webkit and go. Its interesting t…

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    Surfin’ Safari – Blog Archive » Introducing Drosera
    June 28th, 2006 | Category: Programming […]

  15. Pingback from Digitaria Blog » Blog Archive » Drosera: WebKit Javascript Debugger Released:

    […] lants, lets you attach and debug JavaScript for any WebKit application—not just Safari.

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  20. Trackback from Backup Brain:

    Safari JavaScript Debugger!

    From Surfin’ Safari, Introducing Drosera: I would like to introduce a new addition to the WebKit open source tools—a JavaScript debugger. Drosera, named after the largest genera of bug eating plants, lets you attach and debug JavaScript for any …

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  24. Trackback from 미남?? ?러쿵저러쿵:

    Drosera, Safari를 위한 JavaScript 벌레 퇴치기(debugger)

    Safari가 사용하고 있는 오픈 소스 웹 브?우져 엔진? WebKit? 개발 버전? 탑재한 WebKit 웹 브?우져를 위한 JavaScript debugger가 발표?었다.
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  25. Pingback from All About Web Technologies » Safari gets a Javascript debugger:

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  26. squareman Says:

    Is there a way to get this to work with _current_ releases of Safari? I tried it and it’s fantabulous for using with the current nightly build of Webkit; however, it would also be most helpful for trouble-shooting sites being delivered to the installed base of Safari users instead of the future ones. Is there a way to do that? (same question for Web Inspector too).

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  29. kitchen utensils Says:

    Great tool. Worked great for my websie. Got all my javascript programmers hooked onto it.

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  33. 3ecomad Says:

    really wonderful.!!!

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  35. kL Says:

    It amazes me that the debugger interface is written in HTML and CSS (it’s probably a bug, but you can click ‘inspect’ on Drosera’s UI elements and see how it’s implemented).

  36. Pingback from MAB Blog » Blog Archive » Apple’s Javascript Debugger: Drosera:

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  40. adampasz Says:

    Sounds great. I’d love to be able to debug my JS code on Safari. Unfortunately, the 2nd to last paragraph of the post that explains how to do this might as well have been written in another language. Until somebody posts a tutorial or something, I guess I’m sticking to alert statements…

  41. Pingback from » Safari Bugs (Bring on OS 10.5 Leopard) » Shane Shepherd: web design and development; music:

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  43. footcow Says:

    One thing I don’t understand about Drosera and WebKit … First is there any forum to ask questions ? Second I don’t understand why I have some functionnalities that are not running using Safari … and when I try to debug them with WebKit + Drosera … everything is running perflectly … !? Any idea to help me about this point ?

  44. zenslug Says:

    I had a lot of hope with Drosera, but it is pretty difficult to use and has limited functionality. Firebug for Firefox is so much better, I just don’t understand why Safari can’t get a tool of the same caliber. I feel like a monkey with a black box and two metal rods when trying to figure out what the is going on inside Safari, what my JS objects look like.

    How do I set a watch? I can set a break point and sometimes Drosera will show me the structure of the JS objects in scope. Sometimes it just tells me it is an object. That’s not very helpful.

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  46. Garrett Says:

    This has been in WebKit for a year now.

    When will it be available in Safari?

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  58. dotnetCarpenter Says:

    How do I activate Drosera in Windows? I can see a “inspector” folder in the WebKit.resources folder but I don’t see any exe file I can send argument to.

  59. recombinant Says:

    @dotnetCarpenter: if you look at the bottom of this page: you’ll notice that “Drosera is currently not available on Windows. “, which is unfortunate, since personally I’d really like to be able to debug on both platforms. However, the wiki continues by saying that it shouldn’t be that difficult to port — so it’s perhaps we’ll see a Windows version eventually.

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  63. andrew.hedges Says:

    I don’t see any discussion of using Drosera with Dashboard widgets here. Is it possible to attach to a Widget process? I tried doing the defaults write thing, but when I choose “Attach” in Drosera, the Widget doesn’t show up in the list.

  64. Mark Rowe Says:

    @andrew: Dashcode is the tool of choice for debugging JS in widgets. Its debugger has a similar featureset to that in Drosera.