Domain-Driven Design: Tackling Complexity in the Heart of Software

Pattern Name
[Illustration of concept. Sometimes a visual metaphor or evocative text.]
[Context. A brief explanation of how the concept relates to other patterns. In some cases, a brief
overview of the pattern.
However, much of the context discussion in this book is in the chapter introductions and other
narrative segments, rather than within the patterns.
]
[Problem discussion.]
Problem summary.
Discussion of the resolution of problem forces into a solution.
Therefore:
Solution summary.
Consequences. Implementation considerations. Examples.
Resulting context: A brief explanation of how the pattern leads to later patterns.
[Discussion of implementation challenges. In Alexander's original format, this discussion would
have been folded into the section describing the resolution of the problem, and I have often
followed Alexander's organization in this book. But some patterns demand lengthier discussions of
implementation. To keep the core pattern discussion tight, I have moved such long
implementation discussions out, after the pattern.
Also, lengthy examples, particularly those that combine multiple patterns, are often outside the
patterns.]
[ Team LiB ]

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[ Team LiB ]
GLOSSARY
Here are brief definitions of selected terms, pattern names, and other concepts used in the book.
AGGREGATE
A cluster of associated objects that are treated as a unit for the purpose of data changes.
External references are restricted to one member of the 
AGGREGATE
, designated as the 
root.
A set of consistency rules applies within the 
AGGREGATE'S
boundaries.
analysis pattern
A group of concepts that represents a common construction in business modeling. It may be
relevant to only one domain or may span many domains (Fowler 1997, p. 8).
ASSERTION
A statement of the correct state of a program at some point, independent of how it does it.
Typically, an 
ASSERTION
specifies the result of an operation or an invariant of a design
element.
BOUNDED CONTEXT
The delimited applicability of a particular model. B
OUNDING CONTEXTS
gives team members a
clear and shared understanding of what has to be consistent and what can develop
independently.