Wiki source code of Transformation Mapping (KTM)

Version 14.1 by Alexander Schulz-Rosengarten on 2014/01/23 14:13
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1 = KTM - KIELER Transformation Mapping =
2
3
4
5 === Topics ===
6
7
8
9 {{toc maxLevel="2" minLevel="2"/}}
10
11 This subproject provides a tracing mechanism for arbitary model-elements across multiple model transformations, based on EMF.
12
13 The main propose of KTM is to allow bidirectional information transfer between abstract models and their resultant transformed models.
14
15 ----
16
17 == Transformation Tree Model ==
18
19
20
21 To offer a mapping between model-elements during multiple transformations KTM introduces a model called TransformationTree to represent these relations.
22
23 It is based on an EMF-Metamodel.
24
25 [[image:attach:als-ktmt-metamodel.png]]
26
27 The structure of the model can be separated into two parts.
28
29 **First part** (upper half) is a tree of transformations. Each ModelWrapper-class is a representation of a model which is transformed. So ModelWrapper are nodes and ModelTransformations are edges. Thus the ModelWrapper representing the initial-source-model of all transformation is also the root of a TransformationTree-model.
30
31 **Second part** (lower half) is object-mapping. Instances of models contain EObjects as their elements, which are represented by EObjectWrapper-class in this metamodel. The EObjectWrapper of two models are connected with EObjectTransformations-class to express their origination relationship in corresponding model transformation.
32
33
34
35 An abstract example of an instance of this model:
36
37 [[image:attach:abstract_example_tree.png]]
38
39 ----
40
41 == Extensions ==
42
43 Two classes are provided by this project to extend functionality of the core model.
44
45 === TransformationMapping ([[JavaDoc>>attach:TransformationMapping.html]]) ===
46
47 The main propose of this class is generation of a object-mapping during transformation process.
48
49 Therefor it provides different functions for incremental registering of single parent-child-relations between EObjects.
50
51 Furthermore, the extension allows to extract the mapping and check completeness of mapped elements against content of transformed models.
52
53 === TransformationTreeExtensions ([[JavaDoc>>attach:TransformationTreeExtensions.html]]) ===
54
55 This class provides all functionalities to easily traverse and search in a TransformationTree.
56
57 Furthermore, it allows to modify trees by creating, deleting or appending new transformations and transformed models.
58
59 Additionally this extension provides functionality to extract a concrete mapping between two arbitary model intances from a TransformationTree.
60
61 ----
62
63 == Implementation Details ==
64
65 * All references to EObjects in EObjectWrapper are references to a copy of the original EObject. This allows to represent immutable mapping. To reidentify corresponding EObjects TransformationTreeExtensions provides search functions which will check for structural matching models.
66 * Models in TransformationTrees may be transient. This indicates that all references to EObjects in all Elements of the transient model are removed. Thus these models can't be source of a new appended transformation and can not be associated with it's original model. The main propose of this feature is to improve scalability of TransformationTrees by removing unnecessary references to internal model, but preserve traversing functionality of the object-mapping.
67 * Mappings can be incomplete causing resulting transfromation tree to be incomplete. A incomplete tree does not represent every object in a model with a corresponding Element. This may break some paths of element transformations, but allows to omit model-immanent objects like annotations from mapping. TranformationMapping extension provies a function to check completeness of mapping against its models.
68
69 ----
70
71 == Example ==
72
73 In this example we will perform some transformations on SCCharts.
74
75 The source chart is a ABO, the "Hello World" of SCCharts.
76
77 ABO is already a CoreSCChart, so we will perform normalization and a transformation to SCG.
78
79 === Creating Mapping during Transformation ===
80
81 In order to note every single element transformation of a model transformation, we use the TransformationMapping extension.
82
83 After each creation of new Objects for transformed model the mapping must be updated with it's origin information.
84
85 The codeblock blow show a snipped of SCChartCoreTransformation with additional mapping registration.
86
87
88
89 {{code title="transformTriggerEffect CodeSnipped" theme="Eclipse" linenumbers="true" language="java" firstline="1" collapse="true"}}
90 ...
91  @Inject
92 extension TransformationMapping
93
94 ...
95
96 // NEW - Mapping access delegation
97 def extractMapping() {
98 extractMappingData;
99 }
100
101 ...
102
103 //-------------------------------------------------------------------------
104 //-- S P L I T T R A N S I T I O N --
105 //-------------------------------------------------------------------------
106 // For every transition T that has both, a trigger and an effect do the following:
107 // For every effect:
108 // Create a conditional C and add it to the parent of T's source state S_src.
109 // create a new true triggered immediate effect transition T_eff and move all effects of T to T_eff.
110 // Set the T_eff to have T's target state. Set T to have the target C.
111 // Add T_eff to C's outgoing transitions.
112 def Region transformTriggerEffect(Region rootRegion) {
113 clearMapping; //NEW - clear previous mapping information to assure a single consistent mapping
114 // Clone the complete SCCharts region
115 var targetRootRegion = rootRegion.mappedCopy; //NEW - mapping information (changed copy to mappedCopy)
116 // Traverse all transitions
117 for (targetTransition : targetRootRegion.getAllContainedTransitions) {
118 targetTransition.transformTriggerEffect(targetRootRegion);
119 }
120 val completeness = checkMappingCompleteness(rootRegion, targetRootRegion); //NEW - DEBUG
121 targetRootRegion;
122 }
123 def void transformTriggerEffect(Transition transition, Region targetRootRegion) {
124 // Only apply this to transition that have both, a trigger (or is a termination) and one or more effects
125 if (((transition.trigger != null || !transition.immediate || transition.typeTermination) && !transition.effects.nullOrEmpty) ||
126 transition.effects.size > 1) {
127 val targetState = transition.targetState
128 val parentRegion = targetState.parentRegion
129 val transitionOriginalTarget = transition.targetState
130 var Transition lastTransition = transition
131 val firstEffect = transition.effects.head
132 for (effect : transition.effects.immutableCopy) {
133 // Optimization: Prevent transitions without a trigger
134 if(transition.immediate && transition.trigger == null && firstEffect == effect) {
135 // skip
136 } else {
137 val effectState = parentRegion.createState(GENERATED_PREFIX + "S")
138 effectState.mapParents(transition.mappedParents); //NEW - mapping information
139 effectState.uniqueName
140 val effectTransition = createImmediateTransition.addEffect(effect)
141 effectTransition.mapParents(transition.mappedParents); //NEW - mapping information
142
143 effectTransition.setSourceState(effectState)
144 lastTransition.setTargetState(effectState)
145 lastTransition = effectTransition
146 }
147 }
148 lastTransition.setTargetState(transitionOriginalTarget)
149 }
150 }
151 {{/code}}
152
153 === Create TransformationTree ===
154
155 The following code will now perform each transformation stepwise and updates a transformation tree each step.
156
157
158
159 {{code title="Transform and create TranformationTree" theme="Eclipse" linenumbers="true" language="java" firstline="1" collapse="true"}}
160 aboSplitTE = SCCtransformation.transformTriggerEffect(abo);
161
162 ModelWrapper aboSplitTEModel =
163 transformationTree.initializeTransformationTree(SCCtransformation.extractMapping(), "TriggerEffect", abo, "coreSCChart", aboSplitTE, "coreSCChart-splitTriggerEffect");
164
165 aboNormalized = SCCtransformation.transformSurfaceDepth(aboSplitTE);
166
167 ModelWrapper aboNormalizedModel =
168 transformationTree.addTransformationToTree(SCCtransformation.extractMapping(), aboSplitTEModel, "SurfaceDepth", aboSplitTE, aboNormalized, "normalizedCoreSCChart");
169
170 aboSCG = SCGtransformation.transformSCG(aboNormalized);
171
172 ModelWrapper aboSCGModel =
173 transformationTree.addTransformationToTree(SCGtransformation.extractMapping(), aboNormalizedModel, "SCC2SCG", aboNormalized, aboSCG,"SCG");
174
175 tree = transformationTree.root(aboSCGModel);
176 {{/code}}
177
178
179
180 The resulting TransformationTree has following structure and representing each step and model of the transformation.
181
182
183
184 |=(% colspan="4" style="text-align: center;" %)(% colspan="4" style="text-align: center;" %)
185 (((
186 [[image:attach:example_tree.jpeg]]
187 )))
188 |(% colspan="1" style="text-align: center;" %)(% colspan="1" style="text-align: center;" %)
189 (((
190 [[image:attach:example_abo.jpeg]]
191 )))|(% colspan="1" style="text-align: center;" %)(% colspan="1" style="text-align: center;" %)
192 (((
193 [[image:attach:example_abo_splitTE.jpeg]]
194 )))|(% colspan="1" style="text-align: center;" %)(% colspan="1" style="text-align: center;" %)
195 (((
196 [[image:attach:example_abo_norm.jpeg]]
197 )))|(% colspan="1" style="text-align: center;" %)(% colspan="1" style="text-align: center;" %)
198 (((
199 [[image:attach:example_abo_scg.jpeg]]
200 )))
201
202
203
204 Furthermore the TransformationTree now contains mapping information for the whole transformation chain.
205
206 Now we can use an additional feature of KTM, the resolving of mappings between arbitary models.
207
208 The following code has starts with an instance of the initial ABO SCChart and SCG, along with the TranformationTree above.
209
210
211
212 {{code title="resolveMapping" theme="Eclipse" linenumbers="true" language="java" firstline="1" collapse="true"}}
213 @Inject
214 extension TransformationTreeExtensions
215
216 //Find nodes of model instances in tree
217 val aboSCCModelWrapper = transformationTree.findModel(aboSCC,"coreSCChart");
218 val aboSCGModelWrapper = transformationTree.findModel(aboSCG,"SCG");
219
220 //resolve
221 val mapping = resolvemapping(aboSCCModelWrapper, aboSCC, aboSCGModelWrapper, aboSCG);
222 {{/code}}
223
224
225
226 The returned mapping is a multi mapping between all object in aboSCC and their resulting objects in aboSCG.
227
228 This mapping can now displayed in models or used for various information propagation between elements of the models.
229
230 [[image:attach:example_abo_resolved.jpeg]]
231
232
233
234 Also a more detailed view is available, showing all EObjects relation.
235
236
237
238 [[image:attach:example_abo_resolved_elements.jpeg]]
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240

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