13.7.2017 г.
ENVIRONMENT FOR
SOFTWARE ENGINEERING
EDUCATION (REFACTORING AGENT)
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A.Stoyanova-Doycheva
University of Plovdiv
10th Workshop SEERE 5-12.09.2010
ELEARNING
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CONTENT
Introduction
 rLE Architecture and Implementation
 Refactoring Knowledge Base
 Conclusions
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The Refactoring Agent (RA) is a part from Refactoring
Learning Environment, which is intended to analyze
and assess programming code, based on refactoring
rules.
The Refactoring Agent is responsible for the analysis
and assessment of the code, written by students in
real time by using a set of refactoring methods.
According to the situation and based on the
refactoring method to be applied, the agent could
react in different ways.
Its goal is to show the student, as much as possible,
the weak places of their programming code and the
possible ways to make it better.
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REFACTORING AGENT
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RA FUNCTIONALITY
10th Workshop SEERE 5-12.09.2010
Depending on the refactoring method, which
should be applied, the agent could react in three
different ways:
To apply automatically the method after receiving
confirmation from the user;
 To display detailed instructions, explaining to the
user where and how the particular refactoring
method should be applied;
 To ask the user additional questions in order to
clarify the conditions and define the appropriate
refactoring method.
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Example: Refactoring Proposal (Dynamic HTML)
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Example: Automatic Refactoring
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Example: Refactoring questionary
(Replace Type Code with State/Strategy)
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As a development environment we chose Eclipse
 It is open source
 It supports a powerful mechanism for interaction with
external components in the form of plugins. This could
be considered as a significant advantage of this
particular environment which simplifies the integration
of the Refactoring Agent (RA) in the development
environment.
The sensors and effectors of the agent are realized in JADE
and they use existing plugins in Eclipse.
The agent itself is implemented by means of the JADE
environment .
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IMPLEMENTATION
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BES (JADE)
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RA ARCHITECTURE
FES (IDE)
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sensors
Refactoring
Agent
Local Control
RParser
effectors
RAnalyzer
Refactoring Knowledge Base
Refactoring classes
Rules
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The RKB consists of a set of rules together with a
set of classes, which build a consistent knowledge
base.
 The rules are implemented as Java code and are
specific for each refactoring method.
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RA KNOWLEDGE BASE
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RA KB IMPLEMENTATION
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RA KB PATTERN PACKAGE
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A REFACTORING METHOD IMPLEMENTATION
(DECOMPOSE CONDITIONAL)
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As а source – Martin Fowler’s book “Refactoring
– Improving the Design of Existing Code”
 We discovered а total of 32 methods that can be
implemented in the Knowledge Base.
 We still have 34 methods to investigate.
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REFACTORING METHODS
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1.
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10. Preserve Whole Object
11. Reduce Scope of Variable
12. Remove Assignments to
Parameters
13. Remove Control Flag
14. Replace Assignment with
Initialization
15. Replace Magic Number with
Symbolic Constant
16. Replace Nested Conditional with
Guard Clauses
17. Replace Parameter with Explicit
Methods
18. Replace Static Variable with
Parameter
19. Reverse Conditional
20. Self Encapsulate Field
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3.
Add Parameter
Change Bidirectional
Association to Unidirectional
Consolidate Duplicate
Conditional Fragments
Convert Dynamic to Static
Construction
Convert Static to Dynamic
Construction
Decompose Conditional
Encapsulate Downcast
Introduce Explaining
Variable
Parameterize Method
Preserve Whole Object
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“AUTOMATIC REFACTORING” METHODS
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Introduce Null Object
Introduce Parameter Object
Replace Array with Object
Replace Constructor with Factory Method
Replace Conditional with Polymorphism
Replace Error Code with Exception
Replace Exception with Test
Replace Parameter with Method
Replace Recursion with Iteration
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“REFACTORING PROPOSAL” METHODS
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2.
Replace Type Code with Class
Replace Type Code with State/Strategy
Replace Type Code with Subclass
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“REFACTORING QUESTIONARY” METHODS
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