PHP Error Handling

Priority: P0 (CRITICAL)

Structure

See implementation examples for directory layout.

Build Exception Hierarchies

• Exception-Driven: Favor

  throwing exceptions

  over returning

  false

  or

  null

  for error states.
• Custom Exceptions: Extend

  RuntimeException

  or

  LogicException

  for domain-specific errors.
• Multi-Catch: Use Union types in catch blocks:

  catch (DomainException | InvalidArgumentException $e)

  .

See implementation examples for domain exception hierarchy with multi-catch and finally.

Configure Global Error Handling

• Throwable Interface: Always catch

  Throwable

  for both PHP 7/8 Errors and Exceptions.
• Global Handler: Use

  set_exception_handler

  and

  set_error_handler

  for top-level logging and cleanup.
• Finally: Always use

  finally

  for resource cleanup (e.g., closing file handles, DB connections).
• PSR-3 Logging: Implement

  Psr\Log\LoggerInterface

  for structured error reporting.
• Production Guard: Ensure

  display_errors=Off

  and

  log_errors=On

  in production

  php.ini

  .

Anti-Patterns

• No

  @

  error suppression: Handle or log errors explicitly.
• No empty catch blocks: Log or rethrow all caught exceptions.
• No exceptions for control flow: Reserve for unexpected errors only.
• No

  display_errors

  in production: Log to file; never show users.

References

• Exception & Logging Patterns