Jeremy Ward Pacific Northwest PHP Conference

September 12, 2015

Getting Started With Xdebug

• Developer at Westwerk

• Drummer for Loud Nerves

• Board game geek

• Fan of stand-up comedy

About Me

• About ‘Debugging’

• Xdebug: Overview, Features, and Benefits

• Xdebug Installation and Setup

• Application Debugging and Profiling

Today’s Topics

Our Goal

Understanding Debugging and Context

Evaluating, understanding, and validating how your application works.

What is ‘debugging’?

var_dump()

Context Matters

Xdebug Overview

• PHP extension that provides debugging and profiling capabilities

• Developed by Derick Rethans

• First released in May 2002

• Uses the DBGp debugging protocol

What is Xdebug?

• Debugging support

• Stack trace view

• Profiling

• Code coverage analysis

• Function logging

Features

• Step through code operations line-by-line

• View application data in memory at pre-determined breakpoints

• Access function call stack

• Update variable values during runtime

• More detailed error messaging

Benefits

• Xdebug support exists in over a dozen IDES, including:

• PhpStorm

• Eclipse

• NetBeans

• Plain text editors too (with extensions)!

• VIM

• Sublime Text

• Notepad++

Editor Support

Setup and Configuration

Assumptions

• Pre-installed w/ some environments (MAMP, XAMPP, Vagrant)

• Install from source

• PEAR/PECL

• Detailed instructions at http://xdebug.org/docs/install

Installation

• Locate php.ini file for your PHP installation

• Unsure? Check ‘Loaded Configuration File’ using phpinfo()

• Basic settings needed to enable remote debugging:

• zend_extension=“/path/to/your/xdebug/extension” • xdebug.remote_enable=1 • xdebug.remote_host=localhost • xdebug.remote_port=9000 • xdebug.remote_autostart=1

Configuration

• Used primarily in virtual environments such as Vagrant

• Helps the server layer find the location of local files

• PhpStorm (and presumably other IDEs) include wizards for setting this up

Path Mappings

Using Xdebug

• Add query parameters to the script you’re trying to load:

• Start: [url]?XDEBUG_SESSION_START=[session_name]

• Stop: [url]?XDEBUG_SESSION_STOP=[session_name]

Enabling/Disabling Xdebug

• PhpStorm’s website has a list of recommended browser extensions: https://confluence.jetbrains.com/display/PhpStorm/Browser+Debugging+Extensions

• Chrome:

• Xdebug Helper

• Xdebug Enabler

• Firefox:

• easy Xdebug

• The Easiest Xdebug

• Safari:

• Xdebug Toogler

Browser Extensions

• var_dump() - stylized!

• xdebug_break() - pauses the app as if a breakpoint was set

• xdebug_get_declared_vars() - returns array of elements defined in the current scope.

• Complete list: http://xdebug.org/docs/all_functions

Useful functions

• Profiling

• KCacheGrind (Linux)

• Webgrind: https://github.com/jokkedk/webgrind

• Debugging

• MacGDBp (OSX)

• Aforementioned browser extensions

Tools

Demo

• Xdebug website: http://xdebug.org

• Xdebug and You: Why You Should Be Using a Real Debugger (Juan Treminio) https://jtreminio.com/2012/07/xdebug-and-you-why-you-should-be-using-a-real-debugger/

• Debugging and Profiling PHP with Xdebug (Shameer C) http://www.sitepoint.com/debugging-and-profiling-php-with-xdebug/

Additional Resources

Thank You!Feedback

http://joind.in/15183

Questions? Email: jeremy@jmichaelward.com

Twitter: @_jmichaelward IRC: jmichaelward