meet magento belarus debug pavel novitsky (eng)

Pavel Novitsky

Meet Magento Belarus 2012

Magento Debug Process

Debugging is twice as hard as writing the code in the first place.

Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it.

Brian Kernighan

The main thing about Magento is PHP

Popular practices of PHP applications debugging.

1. Error output

2. Variable values

3. Structured data

4. Code tracing

5. Objects analysis

6. Database query

Error output

In php.ini:

display_errors = Onerror_reporting = E_ALL | E_STRICT

Directly in the application:

ini_set('display_errors', 'On');error_reporting(E_ALL | E_STRICT);

Error outputVariable valuesStructured dataCode tracingObjects analysisDatabase query

Popular practices of PHP applications debugging.

Variable value output

echo $myVar;

Virtually useless.

In most cases — a senseless waste of time.

Error outputVariable valuesStructured dataCode tracingObjects analysisDatabase query

Popular practices of PHP applications debugging.

Structured data output

var_dump($myArray);echo '<pre>'.print_r($myArray, true).

'</pre>';

Array( [key1] => value 1 [key2] => value 2)

Error outputVariable valuesStructured dataCode tracingObjects analysisDatabase query

Popular practices of PHP applications debugging.

array(2) { ["key1"]=> string(7) "value 1" ["key2"]=> string(7) "value 2" }

Code tracing

debug_backtrace() and print_debug_backtrace()

Error outputVariable valuesStructured dataCode tracingObjects analysisDatabase query

Popular practices of PHP applications debugging.

What object do we have?

get_class()

get_class_vars()

get_declared_classes()

method_exists()

Error outputVariable valuesStructured dataCode tracingObjects analysisDatabase query

Popular practices of PHP applications debugging.

Database query

a) echo $sql = "SELECT `some_field1` FROM `table` WHERE `some_field2` = '$var'";

b) $res = mysql_query($sql) or die(mysql_error());

Error outputVariable valuesStructured dataCode tracingObjects analysisDatabase query

Popular practices of PHP applications debugging.

It's good enough for a majority of applications.

But what about Magento?

error_reporting(E_ALL | E_STRICT);ini_set('display_errors', 1);

if (isset($_SERVER['MAGE_IS_DEVELOPER_MODE'])) { Mage::setIsDeveloperMode(true);}

addSetEnv MAGE_IS_DEVELOPER_MODE “true”to .htaccess

Popular practices of PHP applications debugging.

Error output

For intermediate variable verification only.

Still useless.

Standard practices used in Magento

Variable value output

$customer = Mage::getModel('customer/customer')->load(1);

print_r($customer);

Standard practices used in Magento

Structured data output

Mage_Customer_Model_Customer Object ( [_eventPrefix:protected] => customer [_eventObject:protected] => customer [_errors:protected] =>

Array ( ) [_attributes:protected] => [_addresses:protected] => [_addressesCollection:protected] => [_isDeleteable:protected] => 1 [

_isReadonly:protected] => [_resourceName:protected] => customer/customer [_resource:protected] => [_resourceCollectionName:protected] =>

customer/customer_collection [_cacheTag:protected] => [_dataSaveAllowed:protected] => 1 [_isObjectNew:protected] => [_data:protected] =>

Array ( [entity_id] => 1 [entity_type_id] => 1 [attribute_set_id] => 0 [website_id] => 1 [email] => john.doe@example.com [group_id] => 1 [

increment_id] => 000000001 [store_id] => 1 [created_at] => 2007-08-30 23:23:13 [updated_at] => 2008-08-08 12:28:24 [is_active] => 1 [

firstname] => John [lastname] => Doe [password_hash] => 2049484a4020ed15d0e4238db22977d5:eg [prefix] => [middlename] => [suffix] =>

[taxvat] => [default_billing] => 274 [default_shipping] => 274 ) [_hasDataChanges:protected] => [_origData:protected] => Array ( [entity_id] =>

1 [entity_type_id] => 1 [attribute_set_id] => 0 [website_id] => 1 [email] => john.doe@example.com [group_id] => 1 [increment_id] =>

000000001 [store_id] => 1 [created_at] => 2007-08-30 23:23:13 [updated_at] => 2008-08-08 12:28:24 [is_active] => 1 [firstname] => John

[lastname] => Doe [password_hash] => 2049484a4020ed15d0e4238db22977d5:eg [prefix] => [middlename] => [suffix] => [taxvat] => [

default_billing] => 274 [default_shipping] => 274 ) [_idFieldName:protected] => entity_id [_isDeleted:protected] => [_oldFieldsMap:protected] =>

Array ( ) [_syncFieldsMap:protected] => Array ( ) )

Standard practices used in Magento

Structured data output

Standard practices used in Magento

Useless again?

Standard practices used in Magento

Varien_Object::getData()

Varien_Object::debug()

$customer = Mage::getModel('customer/customer')->load(1);

echo '<pre>'.print_r($customer->debug(), true);

Standard practices used in Magento

Structured data output

[entity_id] => 1

[entity_type_id] => 1

[attribute_set_id] => 0

[website_id] => 1

[email] => john.doe@example.com

[group_id] => 1

[increment_id] => 000000001

[store_id] => 1

[created_at] => 2007-08-30 23:23:13

[updated_at] => 2008-08-08 12:28:24

[is_active] => 1

[firstname] => John

[lastname] => Doe

[password_hash] => 2049484a4020ed15d0e4238db22977d5:eg

[prefix] =>

[middlename] =>

[suffix] =>

[taxvat] =>

[default_billing] => 274

[default_shipping] => 274

Standard practices used in Magento

Structured data output

Code tracing

debug_backtrace()

print_debug_backtrace()

Standard practices used in Magento

Varien_Debug::backtrace()

Standard practices used in Magento

Object analysis

get_class()

get_class_vars()

get_declared_classes()

method_exists()

Used everywhere in Magento

Database queries

echo $sql = "SELECT `some_field1` FROM `table`”;

$res = mysql_query($sql) or die(mysql_error());

Standard practices used in Magento

Database queries

Display a query:

$myCollection->load(true);

Write a query to the system log:

$myCollection->load(false, true);

Standard practices used in Magento

Database queries

$model = Mage::getModel('catalog/product')->getCollection();$sql = $model->getSelect()->__toString();echo $sql;

Standard practices used in Magento

Mage::getModel('catalog/product')->getCollection()->load(true);

SELECT `e`.* FROM `catalog_product_entity` AS `e`

Database queries

Write all the queries to var/debug/pdo_mysql.log

Standard practices used in Magento

lib/Varien/Db/Adapter/Pdo/Mysql.php:

protected $_debug = true; protected $_logAllQueries = true;

What else?

Logging

Let’s experiment

<?php

error_reporting(E_ALL | E_STRICT);ini_set('display_errors', 1);

$mageFilename = 'app/Mage.php';require_once $mageFilename;

Mage::setIsDeveloperMode(true);umask(0);

Mage::app();

// … our code …

— developer’s Swiss knife

DEBUGGING and PROFILING

Installation

xdebug.profiler_enable_trigger=onxdebug.remote_autostart=offxdebug.remote_enable=1xdebug.remote_host="127.0.0.1"xdebug.remote_port=9000xdebug.remote_handler="dbgp"xdebug.idekey="netbeans"xdebug.collect_vars=onxdebug.collect_params=4xdebug.show_local_vars=onxdebug.var_display_max_depth=5xdebug.show_exception_trace=on

zend_extension=/usr/lib/php5/20090626+lfs/xdebug.so

; zend_extension_ts="c:\php\ext\php_xdebug-2.0.1-5.2.1.dll"

xDebug

http://xdebug.org/download.php

Setting up

xDebug

Setting up NetBeans IDE

xDebug

Well, what good will that do?http://example.com/index.php?XDEBUG_SESSION_START=netbeans

xDebug

http://example.com/index.php?XDEBUG_SESSION_START=netbeans

easy Xdebug http://bit.ly/LKpvjC

Xdebug helper http://bit.ly/KuCo2c

Profiling

xdebug.profiler_enable=1

xDebug

Logs visualization

xDebug — profiling

Webgrind http://bit.ly/LXMGFJ

Kcachegrind http://bit.ly/KGzyAw

WinCacheGrind http://bit.ly/Nh4iPY

Xdebugtoolkit http://bit.ly/LmB4t9

MacCallGrind http://bit.ly/LlerGS

CachegrindVisualizer http://bit.ly/OD6dLy

The client visited…

<disable_local_modules>true</disable_local_modules>

<config><modules>

<Some_Module><active>false</active>

<Some_Module></modules>

</config>

Commerce Bug http://bit.ly/M8ggqh

Magento Connect — developer tools

Developer Toolbar for Magento http://bit.ly/LnSW8s

Magento Connect — developer tools

Advanced Developer Tools http://bit.ly/Lo1Vqa

Magento Connect — developer tools

Only for versions 1.6.1 and earlier

Developer Toolbar http://bit.ly/LnD1Hk

Magento Connect — developer tools

Magento FirePHP http://bit.ly/LnYGyX

Magento Connect — developer tools

Mage::helper('firephp')->send('Lorem ipsum sit amet ..');Mage::helper('firephp')->debug(Mage::getModel('catalog/product')->load(54));

Magento Connect — developer tools

Developer Helper http://bit.ly/OLauwz

THANK YOU FOR YOUR ATTENTION

pavel@belvg.com