N/APosted on - 07/16/2011
I created a plugin that can read the length property of elements. How can I return back to the old line on which the program always points to a certain line where it cannot convert the variable and returns a null variable when I attempt to computer for the length
This is the error that I get
Uncaught TypeError: Cannot read property 'length' of undefined
Hi roger read your question and I think that it is related to a problem where Java is installed but not working properly. So first you need to make sure that the Java plug-in is enable in your Mozilla browser by doing this Enable Java in options/preferences Also if you are starting it in Firefox 3.6 "Enable Java" option is not available and you have to use Add-ons manager. In Mozilla suite go in to the edit tool barand then preferencesscroll down to the menu of advanced options and then select out the enable java option.Chect out if by doing this your problem is solved or not. Thanks
In case of using minified scripts, any debugger can show you the same problem line and this information isn't useless.
There are some steps to follow to solve your problem:
As i said: for developing use not minified scripts, debugger will show you lines that mean something and if you are lucky you can find very interesting remarks of another developer.
In case you don’t dispose of a full version of the scripts, you can use unminifier like:http://jsbeautifier.org/. Add to your project uminified script and run invalid function again. Debugger, like expected shows you the line, but this time you will see a real logic line and you can understand what are the problems.
Debugger will show you which script throws problem. Check if there any newer version of this script. Found exact line of the minified scripts, name of plugin and then found that there is a newer version available.
Google your errors with scripts names – it can help you! When doing it – Google will return pages with similar phrases in text.
Hope you find solution to your problem.