book

The Art of Modern PHP 8

by Joseph Edmonds

October 2021

Intermediate to advanced

420 pages

English

Packt Publishing

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ForewordContributorsAbout the authorAbout the reviewer
Who this book is forWhat this book coversTo get the most out of this bookDownload the example code filesConventions usedGet in touchShare Your Thoughts
What is OOP?Understanding the phraseOOP alternativesLearning object-oriented PHPPHP OOP basicsClassesInterfacesNamespacesSummary
Encapsulation and visibilityPrivate, protected, and publicInheritance–the classical parent, child, and "is a" styleConstructor promotionComposition–the modern, flexible "has a" styleInterfaces instead of abstract classesSummary
SPL – the Standard PHP LibraryData structuresIteratorsExceptions and error handlingYoda and Pokemon exception handlingException and error handling best practicesMeta-programming with reflection and attributesReflectionAttributesSummary
Scalar typesStringsIntsFloatsBools Type jugglingType and value comparisonArrays and iterablesArraysIterablesDocBlock typesNullable, void, and uninitializedNull and nullableVoidUninitializedResourcesSummary
Object type inheritanceObject comparisonPassing objects by referenceMaking new objectsSummary
Coercive and strict modesCovariance and contravarianceContravariance – that is, allowing less specific parameter types than the parentCovariance – that is, allowing more specific return types than the parentRemembering the rulesSummary

Clean Code Acronyms (CCA)DRYKICKDesign patternsCreational patternsStructural patternsBehavioral patternsArchitectural patternsSummary
Model, View, Controller – MVCControllerFront controllerModelEntity patternUniversally unique identifier (UUID)Persistence and ORMSingleton anti-patternRepository patternCollection patternViewIt livesSummary
Inversion of control containerDependency injection and the service locatorThe service locator anti-patternSummary
What is Composer?What are dependencies?Dependency resolutionBut wait, there's moreIn a nutshell, it's awesomeGet it installed!Composer autoloaderOld-fashioned versus autoloadedA real-world, old-fashioned exampleExtra pointsAutoloading in PHPConfiguring Composer autoloaderUsing Composer to require packagesFinding dependenciesInitialization of composer.jsonWhat is a vendor?Minimum stabilityPackage typeLicenseSo far, so goodInstalling monologIgnore the vendor directory in your VCSThe composer.lock fileAdding extra dependenciesVersion constraintsSemVer in a nutshellCaret (^) Version RangeTilde (~) Version RangeExact versionVersion rangeMultiple acceptable versionsFull documentationDev and prod dependenciesRequiring dev dependenciesInstalling without dev dependenciesSummary
Writing composer.jsonNameDescriptionKeywordsLicenseUsing source folders and namespacesExecutable Binaries Configured under binExtensionless filesExecutable permissionsFinding an autoloaderUsing versions and taggingCreating a Git tagSemVerStable and development versionsPrivate Git repos as Composer dependenciesPublishing on PackagistThings to check before you publishSubmitting your package to PackagistCreatedIf you were just testing, delete itSummary
EnumerationsBasic and backed enumsCreating enum instancesNot just classes with casesReadonly propertiesReadonly gotchasIntersection typesNever return typeFinal constantsSummary – end of the book
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Content preview from The Art of Modern PHP 8

Chapter 9: Dependency Injection Example

In this chapter, we are going to look at a very popular pattern in modern PHP – the dependency injection (DI) container. This is a system that acts as a global application-level factory and combines configuration and instance management.

You could have a read through Fabien Potencier's article from way back in 2009, which tried to educate the PHP masses about what a DI container is and why we should be using one:

http://fabien.potencier.org/do-you-need-a-dependency-injection-container.html.

Bear in mind that this is a vintage article, but the basic points are all there, and it is worth a read through. It's also an interesting bit of PHP history.

We're going to learn all about what a DI container does ...