Strategy Pattern

by vlado on Tue, 2006-07-25 08:17

Intent

Select algorithms on-the-fly at runtime.

Motivation

Write different loggers

Implementation

a strategy is a variable whose value is a function or method
No need for separate classes that differ in a few well understood ways
Strategy objects are not a no-no, but there is no inherent need for separate classes for each strategy instance

Examples

with functions

$logger = "a_logger_function";
$logger($message);

with objects

$strategy = "a_logger_class";
$log_object = new $strategy;
$log_object->log(message);

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