Table of Contents
Foreword.
Preface.
Acknowledgments.
I. PUTTING THE DOMAIN MODEL TO WORK.
1. Crunching Knowledge.
Ingredients of Effective Modeling. Knowledge Crunching. Continuous
Learning. Knowledge-Rich Design. Deep Models.
2. Communication
and the Use of Language.
UBIQUITOUS LANGUAGE. Modeling Out Loud. One Team, One Language.
Documents and Diagrams. Written Design Documents. Executable
Bedrock. Explanatory Models.
3. Binding Model and
Implementation.
MODEL-DRIVEN DESIGN. Modeling Paradigms and Tool Support. Letting
the Bones Show: Why Models Matter to Users. HANDS-ON MODELERS.
II. THE BUILDING BLOCKS OF A MODEL-DRIVEN DESIGN.
4. Isolating the Domain.
LAYERED ARCHITECTURE. Relating the Layers. Architectural
Frameworks. The Domain Layer Is Where the Model Lives. THE SMART UI
“ANTI-PATTERN” Other Kinds of Isolation.
5. A Model Expressed in
Software.
Associations. ENTITIES (A.K.A. REFERENCE OBJECTS). Modeling
ENTITIES. Designing the Identity Operation. VALUE OBJECTS.
Designing VALUE OBJECTS. Designing Associations That Involve VALUE
OBJECTS. SERVICES. SERVICES and the Isolated Domain Layer.
Granularity. Access to SERVICES. MODULES (A.K.A. PACKAGES). Agile
MODULES. The Pitfalls of Infrastructure-Driven Packaging. Modeling
Paradigms. Why the Object Paradigm Predominates. Nonobjects in an
Object World. Sticking with MODEL-DRIVEN DESIGN When Mixing
Paradigms.
6. The Life Cycle of a Domain Object.
AGGREGATES. FACTORIES. Choosing FACTORIES and Their Sites. When a
Constructor Is All You Need. Designing the Interface. Where Does
Invariant Logic Go? ENTITY FACTORIES Versus VALUE OBJECT FACTORIES.
Reconstituting Stored Objects. REPOSITORIES. Querying a REPOSITORY.
Client Code Ignores REPOSITORY Implementation; Developers Do Not.
Implementing a REPOSITORY. Working Within Your Frameworks. The
Relationship with FACTORIES. Designing Objects for Relational
Databases.
7. Using the Language: An Extended Example.
Introducing the Cargo Shipping System. Isolating the Domain:
Introducing the Applications. Distinguishing ENTITIES and VALUE
OBJECTS. Role and Other Attributes. Designing Associations in the
Shipping Domain. AGGREGATE Boundaries. Selecting REPOSITORIES.
Walking Through Scenarios. Sample Application Feature: Changing the
Destination of a Cargo. Sample Application Feature: Repeat
Business. Object Creation. FACTORIES and Constructors for Cargo.
Adding a Handling Event. Pause for Refactoring: An Alternative
Design of the Cargo AGGREGATE. MODULES in the Shipping Model.
Introducing a New Feature: Allocation Checking. Connecting the Two
Systems. Enhancing the Model: Segmenting the Business. Performance
Tuning. A Final Look.
III. REFACTORING TOWARD DEEPER INSIGHT.
8. Breakthrough.
Story of a Breakthrough. A Decent Model, and Yet…. The
Breakthrough. A Deeper Model. A Sobering Decision. The Payoff.
Opportunities. Focus on Basics. Epilogue: A Cascade of New
Insights.
9. Making Implicit Concepts Explicit.
Digging Out Concepts. Listen to Language. Scrutinize Awkwardness.
Contemplate Contradictions. Read the Book. Try, Try Again. How to
Model Less Obvious Kinds of Concepts. Explicit Constraints.
Processes as Domain Objects. SPECIFICATION Applying and
Implementing SPECIFICATION.
10. Supple Design.
INTENTION-REVEALING INTERFACES. SIDE-EFFECT-FREE FUNCTIONS.
ASSERTIONS. CONCEPTUAL CONTOURS. STANDALONE CLASSES. CLOSURE OF
OPERATIONS. DECLARATIVE DESIGN. Domain-Specific Languages. A
Declarative Style of Design. Extending SPECIFICATIONS in a
Declarative Style. Angles of Attack. Carve Off Subdomains. Draw on
Established Formalisms, When You Can.
11. Applying Analysis
Patterns.
12. Relating Design Patterns to the Model.
STRATEGY (A.K.A. POLICY). COMPOSITE. Why Not FLYWEIGHT?
13.
Refactoring Toward Deeper Insight.
Initiation. Exploration Teams. Prior Art. A Design for Developers.
Timing. Crisis as Opportunity.
IV. STRATEGIC DESIGN.
14. Maintaining Model Integrity.
BOUNDED CONTEXT. Recognizing Splinters Within a BOUNDED CONTEXT
CONTINUOUS INTEGRATION. CONTEXT MAP. Testing at the CONTEXT
Boundaries. Organizing and Documenting CONTEXT MAPS. Relationships
Between BOUNDED CONTEXTS. SHARED KERNEL. CUSTOMER/SUPPLIER
DEVELOPMENT TEAMS. CONFORMIST. ANTICORRUPTION LAYER. Designing the
Interface of the ANTICORRUPTION LAYER. Implementing the
ANTICORRUPTION LAYER. A Cautionary Tale. SEPARATE WAYS. OPEN HOST
SERVICE. PUBLISHED LANGUAGE. Unifying an Elephant. Choosing Your
Model Context Strategy. Team Decision or Higher. Putting Ourselves
in Context. Transforming Boundaries. Accepting That Which We Cannot
Change: Delineating the External Systems. Relationships with the
External Systems. The System Under Design. Catering to Special
Needs with Distinct Models. Deployment. The Trade-off. When Your
Project Is Already Under Way. Transformations. Merging CONTEXTS:
SEPARATE WAYS—SHARED KERNEL. Merging CONTEXTS: SHARED
KERNEL—CONTINUOUS INTEGRATION. Phasing Out a Legacy System. OPEN
HOST SERVICE—PUBLISHED LANGUAGE.
15. Distillation.
CORE DOMAIN. Choosing the CORE. Who Does the Work? An Escalation of
Distillations. GENERIC SUBDOMAINS. Generic Doesn't Mean Reusable.
Project Risk Management. DOMAIN VISION STATEMENT. HIGHLIGHTED CORE.
The Distillation Document. The Flagged CORE. The Distillation
Document as Process Tool. COHESIVE MECHANISMS. GENERIC SUBDOMAIN
Versus COHESIVE MECHANISM. When a MECHANISM Is Part of the CORE
DOMAIN. Distilling to a Declarative Style. SEGREGATED CORE. The
Costs of Creating a SEGREGATED CORE. Evolving Team Decision.
ABSTRACT CORE. Deep Models Distill. Choosing Refactoring Targets.
16. Large-Scale Structure.
EVOLVING ORDER. SYSTEM METAPHOR. The “Naive Metaphor” and Why We
Don't Need It. RESPONSIBILITY LAYERS. Choosing Appropriate Layers.
KNOWLEDGE LEVEL. PLUGGABLE COMPONENT FRAMEWORK. How Restrictive
Should a Structure Be? Refactoring Toward a Fitting Structure.
Minimalism. Communication and Self-Discipline. Restructuring Yields
Supple Design. Distillation Lightens the Load.
17. Bringing the
Strategy Together.
Combining Large-Scale Structures and BOUNDED CONTEXTS. Combining
Large-Scale Structures and Distillation. Assessment First. Who Sets
the Strategy? Emergent Structure from Application Development. A
Customer-Focused Architecture Team. Six Essentials for Strategic
Design Decision Making. The Same Goes for the Technical Frameworks.
Beware the Master Plan.
Conclusion.
Appendix: The Use of Patterns in This Book.
Glossary.
References.
Photo Credits.
Index. 0321125215T08272003About the Author
Eric Evans is the founder of Domain Language, a
consulting group dedicated to helping companies build evolving
software deeply connected to their businesses. Since the 1980s,
Eric has worked as a designer and programmer on large
object-oriented systems in several complex business and technical
domains. He has also trained and coached development teams in
Extreme Programming.