Pro PHP- Patterns, Frameworks, Testing and More

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CHAPTER 13

SPL Exceptions

The SPL provides a number of built-in exception base classes that are designed to handle

everyday scenarios. In this chapter, you will learn about the base exception classes, when to

apply them, and how to extend them for your own requirements.

Logic Exceptions

The SPL has two central classes of exceptions: LogicException and RuntimeException (discussed in

the next section). The LogicException class descends from Exception directly, and does not

add any additional methods.

class LogicException extends Exception

The purpose of this classification is to allow you to differentiate between compile-time

logical exceptions and exceptions caused by bad data being passed to the application.

Invoking a logic exception is just like invoking a standard exception, except that it should

be thrown only on the condition that the application is programmed incorrectly. This type of

exception can be used to create a system for logging programming exceptions separately from

those caused by runtime data.

To get started, Listing 13-1 shows how to invoke a logic exception and a typical scenario

where you might correctly use a LogicException directly.

Listing 13-1. Throwing LogicException

class Lazy {

protected $_loaded = false;

protected $_name;

public function materialize() {

$this->_loaded = true;

$this->_name = 'Kevin';

}

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