Page 7 - PHP

The repository pattern separates domain logic from the concrete data access technology by hiding a collection of domain objects behind a simple interface. Understanding the repository pattern in plain PHP lets you test business logic without touching a real database, and swap the underlying storage technology later without touching the rest of the code.

Raw PHP CLI scripts built on $argv hit their limits fast: no validation, no help text, no tests. The Symfony Console component works as a standalone Composer package in any PHP project and provides command classes, prompts, progress bars and exit codes as a solid foundation.

Read/write splitting routes writes to a single primary server and reads to several replicas in order to scale the database layer horizontally. In PHP that concretely means a connection routing layer that picks the right connection depending on the query type, and a deliberate way of handling replication lag so users do not suddenly see stale data right after a write.

PHP generators turn ordinary functions into iterators through the yield keyword, producing values one at a time instead of building an entire result in memory upfront. Instead of loading tens of thousands of CSV rows or a full database result set into an array, a generator delivers one row at a time and keeps memory usage constant regardless of dataset size. Anyone building large imports, exports, or streaming pipelines in PHP 8.4 will run into yield sooner or later.

Custom PHP attributes replace docblock annotations with a compiler-parsed, type-safe syntax: a class marked with #[Attribute] defines the structure, Attribute::TARGET flags restrict the allowed target, and a ReflectionClass reads the data at runtime, all without a fragile string parser for comments.

Many PHP APIs call themselves REST but are, on closer inspection, RPC calls wrapped in HTTP: one POST endpoint per action, always status code 200 regardless of outcome. Genuine RESTful API design in PHP requires resources instead of actions, correctly applied HTTP verbs, deliberate status codes and idempotency where it is expected, and none of that needs a framework to implement cleanly.

A leap from PHP 5.6 straight to PHP 8 skips four major versions, each with its own breaking changes, removed functions and altered error handling. This article shows a multi-stage migration strategy with intermediate versions, a compatibility layer and a test safety net, instead of a risky single-step jump.

Testability is not created when the tests are written, but when the classes themselves are designed. Injecting dependencies, isolating side effects, and avoiding static calls builds code that can be tested without detours, no matter which test framework ends up being used. This article shows the design principles behind testable PHP code, beyond assertions and test runners.

Anyone running custom PHP applications without Symfony or Laravel has to build CSRF protection themselves. With random_bytes for token generation, hash_equals for constant time comparison and a clean session binding, robust CSRF protection can be built in a few lines of PHP, without any third party dependency.

Since PHP 8.0, the JIT compiler translates hot opcode paths into native machine code at runtime, but the effect depends entirely on the workload: numerical computation, image processing, and parsing large volumes of data show measurable runtime gains, while classic, database-heavy web applications barely benefit because wait time on syscalls dominates there. This article explains the architecture of Function JIT and Tracing JIT, the relevant opcache.jit configuration values, and a solid benchmark methodology to measure the actual effect in your own project instead of guessing.