13.6.2 Defi ning Archetypes
An archetype is DK a class or pattern that represents a core abstraction that’s critical to the design of an armature DK for the target system. In general, a fairly
. small set of DK archetypes is needed to design indeed fairly complex systems.
The target system DK armature is composed of these archetypes, which represent stable rudiments DK of the armature but may be expressed numerous different
. ways grounded on the geste of the system.
In numerous cases, archetypes DK can be deduced by examining the analysis classes
. defi ned as part DK of the conditions model. Continuing the discussion of the
SafeHome home DK security function, you might defi ne the following archetyp.es
. • Knot. Represents a cohesive DK collection of input and affair rudiments of
the home security DK function. For illustration, a knot might be composed of
. (1) colorful detectors DK and (2) a variety of alarm ( affair) pointers.
• Sensor. An DK abstraction that encompasses all seeing outfit that
feeds information into DK the target system.
• Indicator. An abstraction DK that represents all mechanisms (e.g., alarm temptress,
. fl ashing lights, bell) for indicating that an alarm condition is being.
• Controller. An DK abstraction that depicts the medium that allows the
arming or disarming DK of anode.However, they
, If regulators live on anetwork.have the capability to communicate with DK one another.
13.6.3 Refi ning the Architecture into Components
As the software armature DK is refi ned into factors, the structure of the system begins to crop. But how are these DK factors chosen? In order to answer
this question, you begin DK with the classes that were described as part of the conditions model. 6
These analysis classes DK represent realities within the operation ( business) sphere that must be addressed within the software armature.
Hence, the operation DK sphere is one source for the derivate and refi nement
. of factors. Another source is the structure sphere. The armature
must accommodate DK numerous structure factors that enable operation
factors but have no DK business connection to the operation sphere. For illustration, memory operation DK factors, communication factors, database factors, and task DK operation factors are frequently integrated into
. the software armature.
The interfaces DK depicted in the armature environment illustration ( Section13.6.1)
indicate one or further DK technical factors that reuse the data that fl ows
across the DK interface. In some cases (e.g., a graphical stoner interface), a complete
. subsystem armature with DK numerous factors must be designed.
Continuing the SafeHome home DK security function illustration, you might defi ne
. the set of top- position DK factors that address the following functionality
• External communication operation — coordinates communication of
the security function DK with external realities similar as other Internet- grounded
systems and external alarm notifi cation.
• Control panel DK processing — manages all control panel functionality.
• Sensor operation — coordinates access to all sensors attached to the
• Alarm processing — verifi es DK and acts on all alarm conditions.
Each of these top- position DK factors would have to be developed iteratively
and also deposited DK within the overall SafeHome armature. Design classes
(with applicable attributes DK and operations) would be defi ned for each. It’s important to note, still, that the design DK details of all attributes and operations
. would not be specifi ed until element- position design ( Chapter 14).
The overall architectural DK structure ( represented as a UML element illustration) is illustrated in Figure13.8. Deals DK are acquired by external communication operation as they move in from factors that reuse the
SafeHome GUI and the DK Internet interface. This information is managed by a
SafeHome administrative DK element that selects the applicable product function
(in this case security). The control panel processing DK element interacts with
the homeowner DK to arm/ disarm the security function. The sensor operation
The architectural design DK that has been modeled to this point is still fairly
grandly position. The DK environment of the system has been represented, archetypes that indicate the DK important abstractions within the problem sphere have been defi ned,
. the overall DK structure of the system is apparent, and the major software factors have been identifi ed. Still, farther DK refi nement ( recall that all design is
. iterative) is still necessary.
To negotiate this, an factual externalization of the armature is developed. By
this we mean that the DK armature is applied to a specifi c problem with the intent
of demonstrating that DK the structure and factors are applicable.
Figure13.9 illustrates DK an externalization of the SafeHome armature for the
security system. Factors DK shown in Figure13.8 are developed to show fresh detail. For illustration, the sensor DK operation element interacts with
.13.6.5 Architectural DK Design for Web Apps
are customer- garçon operations generally structured using multilayered
infrastructures, including DK a stoner interface or view subcaste, a regulator subcaste which
. directs the fl ow of DK information to and from the customer cybersurfer grounded on a set of
business rules, and DK a content or model subcaste that may also contain the business
. rules for the WebApp.
The stoner DK interface for a WebApp is designed around the characteristics of the
web cybersurfer running DK on the customer machine ( generally a particular computer or mobile
device). Data layers DK live on a garçon. Business rules can be enforced using a
garçon- grounded DK scripting language similar as PHP or a customer- grounded scripting language
The architectural DK design of a WebApp is also infl uenced by the structure ( direct or nonlinear) of the content that needs to be penetrated by the customer DK.
The architectural factors ( Web runners) of a WebApp are designed DK to allow control
to be passed to other system factors, allowing veritably fl exible navigation DK structures. The physical position of media and other content coffers also infl uences
the architectural DK choices made by software masterminds