Debugging webOSDebugging webOSApplicationsApplications

Steve LemkewebOS Tools Engineering

April 23, 2010

About Me

• Tools Engineer at Palm• Palm (webOS) Emulator• Internal and external SDK/PDK tools

• Previously• Palm Computing (acquired by US Robotics)• US Robotics (acquired by 3Com)• 3Com (spun out Palm Inc.)• Palm Inc. (spun out PalmSource)• PalmSource (acquired by Access Systems)

Overview

• General Connectivity• JavaScript Logging• Palm Inspector and WORM• Host Mode for WebKit Inspector• Command Line Debugging• Ares Debugger• Emulator Tips and Tricks• Command Line Tips• Helpful Resources• Q & A

General Connectivity

• IP vs. USB• IP over USB is tricky

• novacom and novaterm• Default target is most recently connected target• Helpful if you realize it; confusing if not• Leave emulator running• Tip: connect device only when needed, then disconnect

• ssh• Built-in to emulator (localhost:5522)• Can be added to device (“pdk-device-install”)• Useful on Windows (Putty)• Can tunnel other ports (but novacom will too)

JavaScript Logging

• Use “Mojo.Log.Info” instead of “console.log”

• Viewing log output:• Good: “novaterm” + “tail -f /var/log/messages”• Better: “palm-log -f com.test.app”• Best: Ares has built-in log viewer

JavaScript Logging

• To enable logging in framework_config.json:• “loglevel”:99 (enable Mojo.Log.info/warn)

• “logEvents”:true (log framework/mouse events)

• “timingEnabled”:true (log scene transition timing)

• Restore default settings before shipping!• “loglevel”:0 (disable Mojo.Log.info/warn)

• “logEvents”:false (no framework/mouse events)

• “timingEnabled”:false (no scene transition timing)

• MUST change system log level to see info/warn on device!• Default is “error” only

• Type: palm-log --system-log-level info

Palm Inspector

• Launch application with “palm-launch -i <appname>”

• Launch “Palm Inspector” app• Type “palm-inspector” on Linux

• Emulator only

Palm WORM

• Launch “palm-worm” app

• Live graphs of:• Total DOM nodes• Open service handles• JavaScript heap usage

• Emulator only

Host Mode for WebKit Inspector

• Web server running inside Palm Emulator

• Set up a tunnel from host port 5581• ssh -p 5522 -L 5581:localhost:8080 root@localhost• See hints for Windows tunnel on developer.palm.com

• Use Safari (or Chrome) to inspect your app• http://localhost:5581/Apps• http://localhost:5581/PalmApps• Enable “Develop Menu” in Safari: Prefs: Advanced• Right-click and select “Inspect Element”

Command Line Debugging

• novaterm or ssh to device• Type “debug” to run JavaScript debugger (like gdb)

• Hit “enter” to stop/re-start

• Common commands:• “help” and “scripts filename.js”• “break /path/to/file.js:<lineno>”, “en exc all” (catch exceptions)• “info break” and “clear <#>”• “c” (continue), “fin” (step out), “next” (step over), “step” (into)• “bt”, “down”, “up”, “frame <#>”, “scope”• “list, “list -” or “list 5,10”• “info args” or “info locals”• “print <expr>” or “set <var> = <expr>”

Command Line Debugging

• Demo• $ palm-package DebugTest

• $ palm-install com.demo.debug_1.0.0_all.ipk

• $ palm-launch com.demo.debug

• # novaterm

• # debug

• dbg> <return>

• Debugger should display:• break in [anonymous](), [unnamed] line 1 column 1

• Undefined

Command Line Debugging

• Demo (cont’d)• scripts first-assistant.js (list script path)

• b file:///media/…/first-assistant.js:25 (set brkpt)

• en exc all (enable exceptions all)

• c (continue, trigger brkpt)

• bt (backtrace)

• l (list)

• n (step over, hit exception)

• print Mojo.Controller.stageController

• set window.scene = Mojo.Controller.stageController.topScene()

• p scene

• p scene.sceneElement.querySelector('.palm-header').innerHTML

• p scene.sceneElement.querySelector('.palm-header').innerHTML=“foo”

• c (continue; observe header change)

• clear 1 (clear breakpoint; exit debugger)

Ares (IDE) Debugger

• Better than command-line debugger• Source-level debugging• Integrated log viewer• Interactive console

• Don’t have to develop in Ares to debug with it• http://ares.palm.com• Import your project, run, and debug• Use svn (or hg) to avoid re-importing to update

Ares (Standalone) Debugger

• Stand-alone Ares Debugger (NEW!)• Separate from IDE; no sources needed• Just attach and debug• http://ares.palm.com/AresDebug

• Stand-alone Ares Log Viewer• http://ares.palm.com/AresLog

• Ares will also be able to debug devices over USB

Ares (Standalone) Debugger

• Demo

Emulator Tips and Tricks

• GPS, Accelerometer, and Audio• GPS info: Search developer.palm.com for “luna-send”

• Accelerometer: F5 to shake; F6–F9 to rotate

• Sound: http://bit.ly/enableSound

• Suspend and Resume works!• Note: Novacom needs 5–10 seconds to reset

• VirtualBox GUI app• Renaming (or Deleting) VMs

• Prefs: Check for Updates, Auto Capture Keyboard

Emulator Tips and Tricks

• Palm Emulator supports multiple webOS versions

• Current SDK emulator image installed here:• Mac: /Applications/Palm Emulator.app/Contents/Resources/Images

• Linux: /opt/PalmSDK/Current/share/emulator/images

• Windows: C:\Program Files\Palm\SDK\share\emulator\images

• You may store additional vmdk.zip files here:• Mac: ~/Library/Application Support/Palm/SDK/Images

• Linux: ~/.Palm/SDK/Images

• Windows: <user>/Local Settings/Application Data/Palm/SDK/Images

• Save old vmdk.zip before installing newer SDK

Command-Line Tips

• Just remember “palm-help”• Shows all available SDK commands

• Every command supports --help• Even “palm-help --help”• Try “palm-help --sdk-info”

• If emulator won’t boot…• “palm-emulator --list”• “palm-emulator --reset=<vmname>”

• If all else fails…• Remove ~/Library/VirtualBox (deletes all VMs!)• “palm-emulator --debug”

Helpful Resources

• http://developer.palm.com/• Online docs• Developer forums• Forum search is different from site search

• http://www.weboshelp.net/• (Third party site)

• IRC: irc.freenode.net• Firewall blocked? Try port 8000• Join #webos room

&Q A