Slide 1
Slide 1 text
Porting a complex extension to Magento 2
Fabian Schmengler
@fschmengler
Meet Magento Romania 29.10.2016
1 / 62
Slide 2
Slide 2 text
The Extension
IntegerNet_Solr
2 / 62
Slide 3
Slide 3 text
Improved Search and Layered Navigation
More relevant search results
Fuzzy search
Autosuggest window
Filters with multiple selection
Search categories and CMS pages
Boosting of products and attributes
Fetch category pages from Solr for improved performance
3 / 62
Slide 4
Slide 4 text
4 / 62
Slide 5
Slide 5 text
Metrics
2304 Logical Lines of Code
79 Classes (and 3 interfaces)
10 Class rewrites
12 Observers
5 / 62
Slide 6
Slide 6 text
Our Goal:
Reuse
6 / 62
Slide 7
Slide 7 text
Extract independent library
7 / 62
Slide 8
Slide 8 text
Extract independent library
7 / 62
Slide 9
Slide 9 text
Extract independent library
7 / 62
Slide 10
Slide 10 text
Architecture
8 / 62
Slide 11
Slide 11 text
Architecture
8 / 62
Slide 12
Slide 12 text
Architecture
8 / 62
Slide 13
Slide 13 text
Architecture
8 / 62
Slide 14
Slide 14 text
The Plan:
1. Decouple / Extract library
2. Implement M2 bridges
3. Glue together M2 module
9 / 62
Slide 15
Slide 15 text
Step 1:
Refactoring
10 / 62
Slide 16
Slide 16 text
First: TESTS
11 / 62
Slide 17
Slide 17 text
First: TESTS
this is NOT optional!
Slide 18
Slide 18 text
Must have: Integration Tests
e.g. EcomDev_PHPUnit
Nice to have: Functional Tests
e.g. Selenium
Useless: Unit Tests
Don't write unit tests for existing code!
12 / 62
Slide 19
Slide 19 text
Start easy
Find classes with least interaction with Magento
Eliminate dependencies
Small steps
Introduce intermediate solutions if necessary
Deprecate them immediately
13 / 62
Slide 20
Slide 20 text
14 / 62
Slide 21
Slide 21 text
Mage Levels
Mage::throwException()
Mage::getStoreConfig()
Mage::dispatchEvent()
Mage::helper()
Mage::getModel()
Level 1
Final enemy
15 / 62
Slide 22
Slide 22 text
Use own exceptions
Mage::throwException($msg);
⇓
throw new IntegerNet_Solr_Exception($msg);
16 / 62
Slide 23
Slide 23 text
Inject configuration values
public function __construct()
{
$this->host = Mage::getStoreConfig('integernet_solr/server/host');
$this->port = Mage::getStoreConfig('integernet_solr/server/port');
}
⇓
public function __construct($host, $port)
{
$this->host = $host;
$this->port = $port;
}
17 / 62
Slide 24
Slide 24 text
Better: Use Value Objects
represent a value
no identity
immutable
18 / 62
Slide 25
Slide 25 text
Configuration Value Objects
Definition
namespace IntegerNet\Solr\Config;
final class ServerConfig
{
private $host, $port; // ...
public function __construct($host, $port, ...)
{
$this->host = $host;
$this->port = $port;
// ...
}
public function getHost()
{
return $this->host;
}
public function getPort()
{
return $this->port;
}
// ...
}
19 / 62
Slide 26
Slide 26 text
Configuration Value Objects
Usage
Read configuration in Magento module:
$serverConfig = new ServerConfig(
Mage::getStoreConfig('integernet_solr/server/host'),
Mage::getStoreConfig('integernet_solr/server/port'),
// ...
);
Pass $serverConfig value object to library:
$solr = new SolrResource($serverConfig, ...);
20 / 62
Slide 27
Slide 27 text
Interfaces for Helpers
public function __construct()
{
$this->helper = Mage::helper('integernet/solr');
}
$this->helper->getUserQueryText();
⇓
public function __construct(UserQuery $userQuery)
{
$this->userQuery = $userQuery;
}
$this->userQuery->getText();
21 / 62
Slide 28
Slide 28 text
Introduce Interfaces
First define interface for existing code
class IntegerNet_Solr_Helper_Data extends Mage_Core_Helper_Abstract
implements UserQuery
{
public function getUserQueryText();
...
}
namespace IntegerNet\Solr\Implementor;
interface UserQuery
{
/**
* Returns query as entered by user
*
* @return string
*/
public function getUserQueryText();
}
22 / 62
Slide 29
Slide 29 text
Dependency Injection
Then pass helpers as implementation of the interface
class IntegerNet_Solr_Helper_Factory
{
public function getSolrRequest()
{
return new SearchRequestFactory(
Mage::helper('integernet_solr'), // constructor expects UserQuery
...
)->createRequest();
}
}
Note: No Dependency Injection framework involved!
23 / 62
Slide 30
Slide 30 text
Interface Segregation
class IntegerNet_Solr_Helper_Data extends Mage_Core_Helper_Abstract
implements UserQuery, EventDispatcher, SearchUrl
{
...
}
Lean interfaces
Better defined dependencies
Single Responsibility
Split helpers (later)
24 / 62
Slide 31
Slide 31 text
Build bridges for models
"Implementor" interfaces define what library needs from
Magento
Bridge implementation delegates to actual Magento models
25 / 62
Slide 32
Slide 32 text
Remember?
26 / 62
Slide 33
Slide 33 text
Example
27 / 62
Slide 34
Slide 34 text
Service
class ProductModification
{
public function uppercaseDescription($sku) {
$product = $this->productRepository->getProduct($sku);
$product->setDescription(strtoupper($product->getDescription());
$productRepository->saveProduct($product);
}
}
Interfaces
interface ProductRepository {
/** @return Product */
public function getProduct($sku);
public function saveProduct(Product $product);
}
interface Product {
public function getDescription();
public function setDescription($description);
}
28 / 62
Slide 35
Slide 35 text
Bridge: Product
class IntegerNet_Example_Model_Bridge_Product implements Product
{
/** @var Mage_Catalog_Model_Product */
protected $_product;
public function __construct(Mage_Catalog_Model_Product $_product)
{
$this->_product = $_product;
}
public function getDescription()
{
return $this->_product->getDescription();
}
public function setDescription($description)
{
$this->_product->setDescription($description);
}
...
}
29 / 62
Slide 36
Slide 36 text
Bridge: Product (additional methods)
class IntegerNet_Example_Model_Bridge_Product implements Product
{
...
/** @deprecated only use interface methods! */
public function __call($method, $args)
{
return call_user_func_array(array($this->_product, $method), $args);
}
/** @return Mage_Catalog_Model_Product */
public function getMagentoProduct()
{
return $this->_product;
}
}
only use within the Magento module!
__call() useful during refactoring (@deprecated)
30 / 62
Slide 37
Slide 37 text
Bridge: Product Repository
class IntegerNet_Example_Model_Bridge_ProductRepository
implements ProductRepository
{
public function getProduct($sku)
{
$id = Mage::getModel('catalog/product')->getIdBySku($sku);
$magentoProduct = Mage::getModel('catalog/product')->load($id);
return new IntegerNet_Example_Model_Bridge_Product($magentoProduct);
}
public function saveProduct(Product $product)
{
/** @var IntegerNet_Example_Model_Bridge_Product $product */
$product->getMagentoProduct()->save();
}
}
Here we know the concrete type of $product
So we are allowed to use getMagentoProduct()
31 / 62
Slide 38
Slide 38 text
Usage from Magento Controller
class IntegerNet_Example_Adminhtml_ModifierController
extends Mage_Adminhtml_Controller_Action
{
public function uppercaseDescriptionAction()
{
// Instantiation:
$modifier = new ProductModifier(
new IntegerNet_Example_Model_Bridge_ProductRepository()
);
// Call the Service:
$modifier->uppercaseDescription($this->getParam('sku'));
...
}
}
Tipp: move all intantiation into factory "helper"
Less duplication
Magento rewrite system can still be used
32 / 62
Slide 39
Slide 39 text
Divide and
Conquer
33 / 62
Slide 40
Slide 40 text
Split big classes
Approach 1
Extract methods that don’t use any mutable attributes of $this
to other classes
Approach 2
Extract mutable state, grouped with the methods operating on
this state
34 / 62
Slide 41
Slide 41 text
Example
Big "Result" singleton
35 / 62
Slide 42
Slide 42 text
Example
Big "Result" singleton after first extraction
36 / 62
Slide 43
Slide 43 text
Split big classes
Keep as Facade (@deprecated)
Delegate calls to new structure
"Result" example:
Before: 10 public methods, 221 LLOC
After: 6 public methods, 31 LLOC
37 / 62
Slide 44
Slide 44 text
Rebuild Components
Small independent units
Plan, develop bottom up, replace old implementation
New code => TDD, Unit Tests (Yay!)
38 / 62
Slide 45
Slide 45 text
Example
Query strings were escaped with a helper
Used in several places in original code
Introduced value object
final class SearchString
{
public function __construct($rawString) { ... }
public function getRawString() { ... }
public function getEscapedString() { ... }
public static function escape ($string) { ... }
}
Replaced strings that represent query string with
SearchString instance
39 / 62
Slide 46
Slide 46 text
Visualize class dependencies
Use doxygen or pen and paper
Who is talking to whom?
Where are the boundaries?
Where do we want them to be?
Can we minimize the interfaces?
40 / 62
Slide 47
Slide 47 text
Avoid "gold-plating"
No need for perfect implementation
Focus on good abstraction instead
Small and well-defined interface is priority
When it's good enough, stop.
41 / 62
Slide 48
Slide 48 text
Before/After
42 / 62
Slide 49
Slide 49 text
Bigger size
Logical Lines of Code
2304 → 5144 +2840
Classes
79 → 217 +138
Interfaces
3 → 58 +55
43 / 62
Slide 50
Slide 50 text
Less complex units
Ø Cyclomatic complexity / method
2.88 → 2.09 -0.79
Ø Cyclomatic complexity / class
11.35 → 5.34 -6.01
44 / 62
Slide 51
Slide 51 text
Reactions of a Magento 1 developer
wow, that's complicated
unfamiliar code style, not Magento standard
further development seems to take more effort
45 / 62
Slide 52
Slide 52 text
Reactions of a Magento 1 developer
wow, that's complicated
unfamiliar code style, not Magento standard
further development seems to take more effort
After working with it for a few days
got used to it faster than expected
way better IDE integration
more reliable thanks to automated tests
higher code quality
45 / 62
Slide 53
Slide 53 text
Step 2:
M2 Bridge
46 / 62
Slide 54
Slide 54 text
Code Convertion Tools
Useful to get started with module XML files
Don't use them for actual code
Unirgy ConvertM1M2:
https://github.com/unirgy/convertm1m2
Magento Code Migration (official):
https://github.com/magento/code-migration
47 / 62
Slide 55
Slide 55 text
Implement Interfaces
Completely test driven
Do not test (and use) services from the library yet
Unit tests where you know which levers to pull in the core
Integration tests (exploratory) if you still have to figure it
out
48 / 62
Slide 56
Slide 56 text
Step 3:
Integrate
49 / 62
Slide 57
Slide 57 text
Integrate library and Magento 2
take remaining M1 module as example
drive development with integration tests
implement feature by feature
prefer plugins over events and rewrites
50 / 62
Slide 58
Slide 58 text
Use the latest Magento version
you don't want to support Magento 2.0 with a new extension
lock module dependencies in composer.json
"magento/catalog": "^101.0.0"
51 / 62
Slide 59
Slide 59 text
Magento 2 Module Development
follow recommended Magento 2 development practices if
possible
core code should not be taken as an example
refer to devdocs, Stack Exchange (there is a "best-
practice" tag), presentations
52 / 62
Slide 60
Slide 60 text
Magento 2 Module Development
follow recommended Magento 2 development practices if
possible
core code should not be taken as an example
refer to devdocs, Stack Exchange (there is a "best-
practice" tag), presentations
be pragmatic
service contracts are still incomplete
models and collections are more flexible
52 / 62
Slide 61
Slide 61 text
But never use the
Object Manager!
53 / 62
Slide 62
Slide 62 text
Dependency Injection - Interfaces
always depend on the interfaces
defin bridge as preference for implementor
54 / 62
Slide 63
Slide 63 text
Dependency Injection - Services
di.xml also for library classes
types and preferences
factories
55 / 62
Slide 64
Slide 64 text
Dependency Injection - Virtual Types
prefer type specific dependencies over global preferences
virtual types are great
56 / 62
Slide 65
Slide 65 text
Example: Product collection with disabled flat index
disabledFlatStateProductCollectionFactory
disabledFlatStateProductCollection
disabledFlatState
false
57 / 62
Slide 66
Slide 66 text
Questions
FAQ
58 / 62
Slide 67
Slide 67 text
How long did this take?
Original M1 module: ~300 hours
Refactoring: ~150 hours
M2 module: ~300 hours
59 / 62
Slide 68
Slide 68 text
Can you replace Solr with ElasticSearch
If you take the framework agnostic approach to the next
level: yes
create the same boundary between library and search
engine than between library and shop framework
write different adapters
60 / 62
Slide 69
Slide 69 text
Can you replace Solr with ElasticSearch
If you take the framework agnostic approach to the next
level: yes
create the same boundary between library and search
engine than between library and shop framework
write different adapters
But why should we?
Solr is more advanced, ElasticSearch is easier to learn
We already learned Solr
YAGNI
60 / 62
Slide 70
Slide 70 text
More useful resources
Eating ElePHPants keynote (Larry Garfield on the Drupal 8
refactoring)
https://www.youtube.com/watch?v=5jqY4NNnc3I
SOLID MVC presentation (Stefan Priebsch on framework
agnostic domain code)
https://www.youtube.com/watch?v=NdBMQsp_CpE
Mage2Katas video tutorials (Vinai Kopp on TDD with
Magento 2)
http://mage2katas.com/
61 / 62
Slide 71
Slide 71 text
Contact:
www.integer-net.de
[email protected]
@integer_net
@fschmengler
I'm here, talk to me :-)
Read more in our Blog
integer-net.com/m1m2
Shared Code for Extensions
(7 articles)
62 / 62