Tutorials webOS Debugging 101

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If your results are not what you expected, use JavaScript's try/catch/finally block statements to localize the problem. The first thing you want to do is get as close as possible to where you believe the error is occurring. If you're not sure where, start at the beginning.


Add mojo.logs to your code and evaluate them in putty.

Mojo.Log.error("****V" + " my variable: " + this.variable );

Alternatively you can use Mojo.Log.error("my JSON variable: %j", this.jsonObject); or Mojo.Log.error("my JSON variable: "+ JSON.stringify(this.jsonObject)); to log JSON Objects.

putty.exe (for emulator)

ip address "localhost" port 5522

connection type: ssh

when command line opens, type root

no password just hit enter

type: grep payment /var/log/messages

"payment" is the string you are searching for with grep

after you log in to putty:

Mojo.Log.error writes to /var/log/messages

grep: searches for the string following grep within the file specified after the search string, and prints out those lines


SIDE NOTE: if you copy text into the clipboard, you can paste it into putty by right-clicking in putty.

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