CSC/ECE 517 Fall 2009/wiki3 5 SD: Difference between revisions
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In conventional application architecture, lower-level components are designed to be consumed by higher-level components which enable increasingly complex systems to be built. In this composition, higher-level components depend directly upon lower-level components to achieve some task. This dependency upon lower-level components makes applications rigid, fragile and immobile. | In conventional application architecture, lower-level components are designed to be consumed by higher-level components which enable increasingly complex systems to be built. In this composition, higher-level components depend directly upon lower-level components to achieve some task. This dependency upon lower-level components makes applications rigid, fragile and immobile. | ||
Lets consider an example: | |||
Revision as of 16:48, 14 November 2009
Dependency inversion principle
Dependency inversion principle states that:
- High-level modules should not depend on low-level modules. Both should depend on abstractions.
- Abstractions should not depend upon details. Details should depend upon abstractions.
Introduction
In conventional application architecture, lower-level components are designed to be consumed by higher-level components which enable increasingly complex systems to be built. In this composition, higher-level components depend directly upon lower-level components to achieve some task. This dependency upon lower-level components makes applications rigid, fragile and immobile.
Lets consider an example: