ATL: Atlas Transformation Language ATL Starter`s Guide
Contents
1. EA Author2Person B project Author ecore Author km3 Open With ld ds Sample Ecore Model Editor Author2Person asm Open As gt 4 Copy authors ecore System Editor Person ecore Paste In Place Editor Person km3 J Delete y Default Editor Move Rename ey Import r Export Refresh Map to Ecore Run As Team O infos Compare With Replace with Extract KM3 model to KM3 file Extract Ecore metamodel to KM3 Author2Personfauthc Properties Figure 12 Textual edition of the authors ecore model file Debug As Properties Error Log Console Resource in Folder Location 6 Editing the source model Both input and output metamodels of the transformation are now available in the Ecore format Executing the transformation example also requires providing an input model that conforms to the designed input metamodel There is no generic process for editing models Given that the metamodels considered in the present example are quite simple a basic but quite quick method consists in manually editing a simple Ecore model file For this purpose the first step is to create a new file in the same way the KM3 file have been created in Section 5 The created file must have an ecore extension for instance authors ecore Once created the model file has to be edited In order to textually edit an Ecore file select Text Editor in the mouse right click gt 02. in which will appear an outline of the currently edited transformation model or metamodel e The edition view the middle top section aims to display the currently edited file a transformation model or metamodel file e The bottom section contains different views Problems Properties Error Log and Console At this stage the most interesting of these views is the Problems one that will provide information on errors detected at compile time on edited files Page 3 ATL Documentations ATL Starter s Guide Date 07 12 2005 ATL Eclipse SDK File Edit Navigate Search Project ATLEditor Run Window Help E Ean Gava DE Outline 3 An outline is not available 2 Problems 23 Properties Error Log Console D errors O warnings O infos Description Resource In Folder Location Figure 5 The initial ATL perscpective It is now possible to create a new ATL project For this purpose move to the navigator view and select mouse right click gt New gt ATL Project see Figure 6 the name of the project ha to be entered for instance Author2Person Once created the new project shall appear in the Navigator view After a double click on the empty project or after the first operation on this project a project file will appear within the project This file is an XML file generated by Eclipse in order to store metadata relative to the created project Now the ATL project ha
3. Error during the injection of a KM3 file ATL Person ecore Eclipse SDK BAR File Edit Navigate Search Project ATLEditor Run Sample Ecore Editor Window Help ra gt P lt 4 E Oan tS Navigator El 0 E Person ecore X Sm BE Outline 3 aaa ill pS ee NA 3 Y S Resource Set de platform fresource Author2P E ES Author2Person 8 platform fresource Author2Person Person ecore project E HE Person Author ecore i E Person Author km3 name String da Person ecore surname String 1 Person km3 PrimitiveTypes 3 String lt null gt Problems E3 Properties 3 gt Error Log Console Property Value A Changeable ve true Default value tE Default value Literal Derived E False E ttribute Type amp String lt null gt EContaining Class E Person EType E String lt null gt ID tv False Lamar Rewind Wed Selected Object surname String Figure 11 The generic Ecore file editor The metamodels considered in the scope of this transformation are now available under the computable Ecore format Next step is to edit an Author model that conforms to the Author metamodel and that will be used as part of the ATL transformation input Page 8 ATL Documentations ATL Starter s Guide ATL Eclipse SDK DER Fie Edit Navigate Search Project ATL Editor Run Window Help re EM E Car Ez Outline 33 eeu An outline is not available
4. to the rule input element During the execution of the ATL transformation this variable will correspond to the source element currently being matched The OutPattern declares a typed variable which corresponds to the rule output element The OutPattern also specifies a set of Binding elements A Binding describes how a given feature an attribute or a reference of the target element is initialized This initialization must be specified as an OCL expression 8 The present example only requires expressions enabling to access the input element features The considered transformation example aims to transform Author elements from the Author metamodel into Person elements from the Person metamodel A single rule matching Author elements into Person elements is therefore sufficient This rule will be composed of an InPattern in which the source entity Author is declared This source entity is typed by Author Author its couple metamodel_namelentity_name The OutPattern of the defined rule declares in the same way a Person element from the Person metamodel Person Person This OutPattern also defines two bindings that specify the initialization of the Person elements that will be generated by the rule According to the semantics that have been defined in Section 3 the name and surname of created Person elements have to be copied from those of the corresponding source Author element Figure 16 provides an overview of the full code of the Author2P
5. transformation process The figure introduces the name of the files in italics that are going to encode the models authors ecore persons ecore the metamodels Author ecore Person ecore and the ATL transformation Author2Person atl that will be handled during the design of the Author to Person ATL transformation These files along with the way they can be designed in the scope of the ATL development tools are progressively introduced in the rest of this document Note that the transformation to be designed Author2Person atl will have to conform to the ATL transformation metamodel Neither this metamodel nor the Ecore metametamodel will be directly handled during the design of the Author to Person transformation they are associated with no file within Figure 4 The first step in designing an ATL Author to Person transformation is to create a new ATL project This is the focus of the next section 4 Creating a new ATL project The first step after having launched Eclipse is to move to the ATL perspective This is simply achieved by selecting ATL in the Window Open Perspective gt Other menu The title bar of the Eclipse window shall have changed to ATL Eclipse SDK Under the ATL perspective the Eclipse window should look like the window presented in Figure 5 The initial ATL perspective is composed of e The Navigator view on left column in which will appear the ATL projects e The Outline view on right column
6. 2 2005 Moreover a large number of ATL transformations examples from very simple to complex ones are available on the GMT project site 9 in the ATL Transformations section The proposed transformation examples cover many different fields from geometrical transformations to bridges between existing build tools Finally there exists an ATL discussion board 11 enabling the ATL community to share information about ATL and the related model management tools 11 References 1 The ATL Installation Guide Available from the GMT project 10 section ATL Documentation 2 OMG MOF Meta Object Facility MOF 1 4 Final Adopted Specification Document formal 02 04 03 2002 3 Budinsky F Steinberg D Ellersick R Grose T Eclipse Modeling Framework Chapter 5 Ecore Modeling Concepts Addison Wesley Professional ISBN 0131425420 2004 4 Budinsky F Steinberg D Ellersick R Grose T Eclipse Modeling Framework Addison Wesley Professional ISBN 0131425420 2004 5 OMG XMI XML Model Interchange XMI 2 0 Adopted Specification formal 03 05 02 2003 6 The Kernel MetaMetaModel KM3 Manual Available from the GMT project 10 section ATL Documentation 7 The ATL User Manual Available from the GMT project 10 section ATL Documentation 8 OMG OCL Object Constraint Language OCL 2 0 OMG Final Adopted Specification ptc 03 10 14 2003 9 The netbeans Metadata Repository MDR project http mdr net
7. ATL Atlas Transformation Language ATL Starter s Guide version 0 1 December 2005 by ATLAS group LINA amp INRIA Nantes Content 1 TCO CUO AA ANN 1 2 Understanding model transformation cccssccsssccsscesssscssscescescssscesserscescescsssssssescesssssescessscssesceseoeses 1 3 A simple transformation example csssscssssssccsscssssssssssscsssssscssssssssssecsessssssssssssesenessssessessesssesseesssess 2 4 Creating a new ATL project ccccsccsssssccssecssessssssssssscssesssssssssesssessssssssesesssnsesecsseesssesseseessonsesnsesssees 3 5 Designing a NEW MetAMOMEl ooicseciccsecesessseseececsesdovcseesensoovesesyessossesessoseesesusseovessesass sissoo asosa voss sop espeiss soron 4 6 Editing the source MOdel ssssscssscsssssssesssssscsessssssssccsesssessssesesesenesscesecsseessnssessscsscesssnsessssesenesenssseeees 9 7 Programming my first ATL transformati0N ooooocoonnonnocnnconnconnconnocnnonanonononononoconnconnconccanoconocnnconcccn conoces 10 7 1 Creation Of hE ATL Jle a a ated a a ls talca ki Res de 10 7 2 Creation of a new transformation TUll ooonnnnnininnnnnnnvinnnnonnnncnacinccn cenar nana 12 8 Creating my first ATL launch Configuration cscssscssscssscsssssssssscsnsessessssssssessnesssessseesseseseseesseess 14 8 1 Configuring the ATL Configuration tab cccccccccccccssccssseccsseesceseeseeeeseeeecuseescnsesseesecseesecneeescnaeeseeaeeseeas 14 8 2 Configuring the Mod
8. articular ATL knowledge from the user The document is organized as follows e Section 2 introduces the model transformation problematic and the way model transformation could be achieved using ATL e Section 3 describes the transformation example that is going to be developed in the document e Section 4 details the creation of a new ATL project e Section 5 introduces the way new metamodels can be designed using the ATL Tools Development e Section 6 describes the design of a simple input model e Section 7 details the design of the ATL transformation e Section 8 describes the configuration of the transformation launch configuration e Section 9 deals with the transformation execution e Finally Section 10 provides a number of links to advanced ATL resources 2 Understanding model transformation In the field of model engineering models are considered as first class entities A model has to be defined according to the semantics provided by its metamodel a model is said to conform to its metamodel In the same way a metamodel has to conform to a metametamodel In this three layers architecture models metamodels metametamodel the metametamodel usually self conforms to its own semantics e g it can be defined using its own concepts Existing metametamodels include MOF 2 which has been defined by the OMG and Ecore 3 which has been introduced with the Eclipse Modelling Framework EMF 4 Considering model as first c
9. beans org 10 The Generative Model Transformer GMT project http eclipse org gmt 11 The ATL mailing list http groups yahoo com group atl_discussion Page 18 AUN ATL Documentations INRIA ATL Starter s Guide Date 07 12 2005 Appendix A The authors ecore input file lt xml version 1 0 encoding ISO 8859 1 gt lt xmi XMI xmi version 2 0 xmlns xmi http www omg org XMI xmlns Author gt lt Author name David surname Touzet gt lt Author name Freddy surname Allilaire gt lt xmi XMI gt Page 19 CADMABWNKE ATL Documentations VAINRIA ATL Starter s Guide Date 07 12 2005 AppendixB The Author2Person atl file module Author2Person Module Template create OUT Person from IN Author rule Author from a Author Author to p Person Person name lt a name surname lt a surname Page 20
10. e specification of the transformation input and output models In the IN section the field Model enables to define the variable name that will correspond to the input model By convention the input model of an ATL transformation is often called IN in the same way its output model is called OUT The field Metamodel contains the name of the metamodel of this input model Page 11 ATL Documentations INRIA ATL Starter s Guide Date 07 12 2005 ATL Author2Person atl Eclipse SDK File Edit Navigate Search Project ATLEditor Run Window Help de H O A 194 90 2d tS Navigator 23 Author2Person at X B Outline 23 220 module Author2Person Module Template NX te is z create OUT Person from IN Author ee Author2Person a Author2Person Module E project Ge OUT OclModel Author ecore Gha IN OclModel Author km3 Author2Person asm 4uthor2Person atl Person ecore Person km3 E Problems 3 Properties Error Log Console Derrors O warnings O infos Description Resource In Folder Writable Insert Figure 15 An ATL transformation template Once these two fields have been filled the specified couple can be validated by means of the Add button The output model OUT section must be specified in the same way that the input one was At this stage it is possible to note that an ATL transformation may accept several input or outpu
11. ectively correspond to the paths to Author ecore and Person ecore files Similarly the path to the input model corresponds to the path to the authors ecore file Finally a path for the output model file can be defined in the Author2Person project This output file can be named persons ecore Since both the input and output metamodels are defined according to the EMF semantics there is no need to modify the model handlers they are associated with 8 3 The Common tab The last tab of the ATL launch configuration Common enables to specify advanced options Default configuration of these options shall enable to run most of the ATL transformations Detailing these advanced options is not interesting in the scope of this document However interested users will find further details on the subject in the ATL User Manual 7 Page 16 ATL Documentations VAINRIA ATL Starter s Guide Date 07 12 2005 Once the launch configuration has been correctly fulfilled it has to be saved with the Apply button The transformation can then be executed 9 Executing my first ATL transformation Once the launch configuration of a transformation has been correctly fulfilled it can be run as many times as needed without requiring any change to the configuration To run the transformation just go back to the Run window select the created transformation in the ATL Transformation folder on the left column and click on the Run button The ATL engine tr
12. el Choice taby cccccccccccccecssssseesseeseesseeeseeecesecaecaecaaecsceeaeecseeeseeeseeeeeeeeeeenaeenaeenes 15 8 3 The COMMON A tias 16 9 Executing my first ATL transformati0N oooooooncoonnnsonncnonanoonnconnnononncoonnonnnncoon cono nncon nono nncoon ips savose seoses iss 17 10 Conclusion cocoooconnonnnonnocnnocnnoonnconnonnnonnnonnnonoconoconocanoc nooo esos Srp E nooo EEs SEOSES EEEE S SESE VOKE coca noro non nono rones 17 ds A O ANO NOOO 18 Appendix A The authors ecore input file oooooonosmossonnancnanonancnnocnonnocanocanoonnconcconnono nono nonn cono conoconoconocn neones 19 Appendix B The Author2Person atl filO oomommsmmmsmmsmssm9ssrsmssms s 20 Figures List Figure 1 An overview of model transformation c ccsccsscsssresssctserssccsrssssrenssonsersseneesacesaes 2 Figure 2 The Author metamodel A Sa s 2 Figure 3 The Person metano ari ii idas 2 Figure 4 Overview of the Author to Person ATL transformatlON ooccnccoccnocononnocnnonconccnncnnnonnos 3 Figure 5 The initial ATL persepective actors teoria 4 Figure 6 Creation of a new ATL PO ta cod 5 Figure 7 Creation of new li A i iaai 6 Figure 8 The Author metamodel in KM3 forMat oooconcnncnincnocononcncnnnncnnncononncnnnonncnnncnnc cn ncnnnonnos 6 Figure 9 Injecting a KM3 file into an Ecore metamodel oooooncnnncnnccnncnonccoconononnnnoncnoncnnncnnonononnos 7 Figure 10 Error during the injection of a KM3 file scsccssesscosscrsscsesesctorsetscose
13. ernal path Remove lib MM Is MOF 1 4 MM is Ecore Metamodel by URI gt New Delete Apply Revert Figure 19 ATL launch configuration Model Choice Note that whereas for the input model as well as for both input and output metamodels the user just has to select an existing file he or she has to enter the name of the file to be generated for the transformation output model The extension given to this file name must be consistent with the model handler that is used for the output metamodel see below When using the EMF model handler the output model file should be associated with an ecore file extension The Path Editor also enables ATL users to select the model handler that is associated with each declared metamodel Default value for the model handler is EMF It can be modified by selecting and model handler EMF for an Ecore metamodel or MDR 9 for a MOF 1 4 metamodel in the box on top of the buttons column The selection must be validated by means of the Set Model Handler button Note that when setting the metamodel either to MOF 1 4 or Ecore using the dedicated buttons the model handler is automatically set to the MDR for MOF 1 4 or EMF for Ecore In the scope of the considered example the path configuration only makes use of the Set path option since all model and metamodel files are defined within the Author2Person ATL project Thus the paths for the input and the output metamodels resp
14. erscssersneeones 8 Figure 11 The generic Ecore file editor dad 8 Figure 12 Textual edition of the authors ecore model file ooonoonnconicinncniccnoconocnocnnoncnrnnnncnononnos 9 Figure 13 Creation of new A ales ct oad uci de set osaciesscen set atadeains eoteoaet euaeeoies 10 Figur J4 The ATL file wizard iscsi cosets csc eases A A A io 11 Figure 15 An ATL transformation template 1c scscincassesvecscasosenncestesnssetesiedescvvacedseadeesnsedstensees 12 Figure 16 The Author2Person ATL transformation csssseecsseeceecceseeeseseeeceesenceeeceseees 13 Figure 17 Creating a new launch configuration ce eeeeseeeeeeeceecesecseeeseeeeeeseceaeceaeeaeeeneeeeees 14 Figure 18 ATL launch configuration ATL Configuration oconoccconcncnnonconnconcnoncnnncnnananannncnnons 15 Figure 19 ATL launch configuration Model ChOIC8 cooconconnconoconocnoccnoncnanconanononancnnnnancnnccnnoos 16 ATL Documentations VAINRIA ATL Starter s Guide Date 07 12 2005 1 Introduction This document is dedicated to ATL beginner users It aims to provide them with a quick and comprehensive overview of the ATL transformation tool To this end it proposes to guide the user through a step by step simple ATL example It is here assumed that the ATL Development Tools ADT have been previously successfully installed For this purpose please refer to the ATL Installation Guide 1 However this section does not assume any p
15. erson ATL transformation also available in Appendix B Note that the Outline view of the edited ATL transformation is updated as the transformation is edited so that it provides an up to date overview of the structure of the transformation Page 13 ATL Documentations ATL Starter s Guide Date 07 12 2005 ATL Author2Person atl Eclipse SDK File Edit Mavigate Search Project ATLEditor AA Window Help Hs GQ Q RunLast Launched Ctrl F11 E Can Te Debug Last Launched Fil author2r E BE outline 23 module Run History Emplate SNR 7 create Run As gt p 85 Navigator 3 ELA Author2Person S los Author2Person Module B project Run GE OUT OclModel y rule A y da Author ecore Debug History gt pe IN OclModel Gp Author MatchedRule Author km3 fr Author2Person asm Debug As O Author2Person atl to Debug authors ecore Person ecore Q External Tools gt j E Person km3 surname lt a surname persons ecore RE Problems X Properties Error Log Console D errors O warnings O infos Description Resource In Folder Location Figure 17 Creating a new launch configuration 8 Creating my first ATL launch configuration Before being able to execute the designed ATL transformation it is necessary to configure its associated launch configuration An ATL launch configuration aims to resume all the info
16. he structure of the transformation result nor means that the generated result is correct it may contain non structural errors e Finally wherever the ATL transformation is launched from Eclipse or workbench and whatever the model handler of the output model EMF or MDR it is always possible to explore the result file using the basic textual editor mouse right click gt 0Open With gt Text Editor ATL developers can note that the ATL Development Tools include debugging facilities that aims to ease the transformation development process The description of the debugging tools is out of the scope of this introducing document However further details on the debugging functionalities can be found in the ATL User Manual 7 10 Conclusion This document has introduced the ATL transformation language through the presentation of the different steps of the design of a simple ATL transformation example For simplicity sake the example presented in this document only makes use of a small subset of the full ATL facilities There exists a number of documents providing detailed information on the different aspects of the ATL transformation tools Thus users who are interested in discovering the full potential of the ATL transformation language shall refer to the ATL User Manual 7 A detailed description of the KM3 textual notation is also available in the KM3 Manual 7 Page 17 ATL Documentations VAINRIA ATL Starter s Guide Date 07 1
17. ies to serialize the output file whether the transformation contains errors or not Thus in case of errors the content of the serialized file may provide useful information on the type of these errors However this also means that a transformation should have failed although an output model file has been generated At this stage it is therefore advised to check the result of the run transformation There exists several ways to check whether a transformation has completed without error or not e The simplest way to make sure that a transformation has completed without any error is to check whether the transformation has generated error messages At present time this could only be achieved by executing ATL transformations from the Eclipse workbench this requires ATL to be installed from sources In this context the error messages that are generated by the execution of an ATL transformation will be displayed within the Eclipse Console view by default at the bottom of the Eclipse window e While working on a transformation that generates an Ecore model there exists a simple way to check whether this output model is well structured Indeed if the EMF Sample Ecore Model Editor mouse right click gt 0pen With gt Sample Ecore Model Editor allows to explore the content of the output model file the targeted file is well structured This however does neither ensures that the transformation has completed without any error Some errors do not affect t
18. igure 13 This operation opens the ATL File Wizard Page 10 Date 07 12 2005 ATL Documentations VAINRIA ATL Starter s Guide ATL File Wizard HEAD Project Name Author2Person ATL File Name Author2Person ATL File Type module d IN Model IN Metamodel Author ADD Model Metamodel C IN Author OUT Model OUT Metamodel Person Model Metamodel OUT Person LIB LIB LIB Finish Figure 14 The ATL file wizard Date 07 12 2005 The ATL File Wizard see Figure 14 enables the ATL developer to specify some information relative to the transformation e The ATL project the transformation belongs to e The name of the ATL file containing the transformation without extension e The type of the ATL transformation o Module which corresponds to a classical ATL transformation o Query enabling to return a primitive value from a model o Library which defines a set of ATL functions e The input and output models along with their respective metamodels e The ATL libraries that are required by the transformation The present transformation is part of the created Author2Person ATL project The file containing the transformation can be named Author2Person which will lead to the creation of the Author2Person atl file Finally this example corresponds to a classical ATL transformation and the default type module has to be selected Next step corresponds to th
19. ion ASM file Author2Person asm This new file contains the bytecode corresponding to the ATL transformation This bytecode is encoded into an XML format and is updated as the transformation file evolves 7 2 Creation of a new transformation rule Once the ATL transformation file has been created the code of the transformation to be designed can be specified For this purpose this section quickly introduces the basic notions of the ATL language see the ATL User Manual for further details 7 Page 12 ATL Documentations VAINRIA ATL Starter s Guide Date 07 12 2005 ATL Author2Person atl Eclipse SDK File Edit Navigate Search Project ATLEditor Run Window Help mS HOol O Q wleoc E Oan Author2Person atl X 20 module Author2Person Module Template create OUT Person from IN Author rule Author from a Author Author Person Person name lt a name Surname lt a surname writable Figure 16 The Author2Person ATL transformation Besides its header an ATL module is composed of a set of ATL rules Each rule defines the way an input element that is a given type of entity of the input model is transformed into a target element a given type of entity of the output model Both the input and the output elements of a rule are identified by a couple metamodel_name entity_name A rule is composed of an InPattern and an OutPattern The InPattern declares a typed variable which corresponds
20. ion e Model Choice E Common E Java Applet Project Z Java Application Project name Author2Person y Ju JUnit JE JUnit Plug in Test E SWT Application ATL file name Author2Person Author2Per_ Author2Person Author2Person Others parameters Disassembly mode Delete Apply Revert Figure 18 ATL launch configuration ATL Configuration 8 2 Configuring the Model Choice tab The main tab of ATL launch configuration is the Model Choice tab see Figure 19 This tab enables to specify the name of the variables corresponding to involved models and metamodels within the top IN and OUT parts along with the path to the corresponding files in the Path Editor section It also enables to specify the name and the path of the libraries used by the transformation in the Libs section The name of the input model variable IN must be entered in the Model field of the IN section The name of its metamodel variable Author must be specified in the corresponding Meta Model field This couple of variable names can be validated by means of the Add button The output model variable and its corresponding Person metamodel must be specified in a similar way in the OUT section Note that the variable names specified here must correspond to the variable names that appear in the ATL file Once they have been validated both the model and its metamodel appear in the table of the Path Editor section In o
21. ions easier the ATL Development Tools include a simple textual notation dedicated to metamodel edition the Kernel MetaMetaModel KM3 6 This textual notation greatly eases the edition of metamodels Once edited KM3 metamodels can be injected into the Ecore format using ADT integrated injectors The ATL example currently considered only requires a few notions of KM3 The KM3 textual notation is very close to the Java notation Thus a KM3 file is usually used to encode a single metamodel It is composed of e Packages Each package includes a number of classes o Classes A class may define attributes as well as references to other classes for more details on KM3 please refer to the KM3 Manual 6 In the scope of the considered ATL example a metamodel can be associated with a package and an entity with a class It is now possible to edit the considered metamodels in the KM3 format For this purpose two new files have to be created Author km3 for the Author metamodel and Person km3 for the Person metamodel The creation of a new KM3 file is achieved by selecting the File entry in the New gt 0Other gt Simple folder see Figure 7 The name Author km3 and the path of the file to be created have to be entered Page 5 Date 07 12 2005 ATL Documentations ATL Starter s Guide Date 07 12 2005 Select a wizard Create a new file resource Wizards Java Java Emitter Templates Plug in Development Si
22. lass entities requires providing a set of tools defining some operations dedicated to models In this context model transformation appears to be one of the most useful operations on models Model transformation therefore aims to provide facilities for generating a model Mb conforming to a metamodel MMb from a model M conforming to a metamodel MMs A major feature in model engineering is to consider as far as possible all handled items as models The model transformation itself therefore has to be defined as a model This transformation model has to conform to a transformation metamodel that defines the model transformation semantics As other metamodels the transformation metamodel has in turn to conform to the considered metametamodel Page 1 ATL Documentations VAINRIA ATL Starter s Guide Date 07 12 2005 conformsTo conforms To conformsTo conforms To conformsTo conformsTo _M Transformation M Figure 1 An overview of model transformation Figure 1 summarizes the full model transformation process A model Ma conforming to a metamodel MMa is here transformed into a model M that conforms to a metamodel MM The transformation is defined by the model transformation model M which itself conforms to a model transformation metamodel MM This last metamodel along with the MM and MM metamodels has to conform to a metametamodel such as MOF or Ecore 3 A simple transformation example This section i
23. me declared on line 4 is unknown Note that at this stage the generated Ecore files can now be edited by means of the Ecore model editor provided with EMF This editor is opened with double click on the targeted Ecore file Figure 11 provides a screenshot of the edition of the Person ecore metamodel file The Properties view available at the bottom of the perspective see Figure 11 provides information on the element currently selected in the editor view In Figure 11 the surname attribute of the Person entity is currently selected The Properties view displays a set of information related to this model element such as e Changeable which states whether the value of the attribute can be modified is true e Type the type of the attribute is String e EContainingClass the class in which the attribute is defined is Person Page 7 ATL Documentations ATL Starter s Guide Date 07 12 2005 ATL Person km3 Eclipse SDK File Edit Navigate Search Project ATLEditor Run Window Help Vira r an Java To Navigator E Person km3 23 Bz outline 3 SO package Person An outline is not available AAA i E ig Author2Person class Person B project attribute name String Author ecore Q attribute surname Sting Author km3 pe Person km3 package PrimitiveTypes datatype String RR Problems x Properties Error Log Console 1 error O warnings O infos Figure 10
24. mple KFie C Folder F Prniert Cancel Figure 7 Creation of new file Once the creation of the file has been validated the new file appears in the current ATL project in the Navigator view It is now ready to be edited the file is opened by a double click Figure 8 provides a screenshot of the edited Author metamodel Note that the KM3 file must include a specific package PrimitiveTypes that defines all the primitive types that are referred to within the other edited packages KM3 currently defines four primitive data types String Boolean Integer and Double In the scope of the Author metamodel a single primitive type requires to be defined the String data type The Person metamodel can be edited in the same way ATL Author km3 Eclipse SDK File Edit Navigate Search Project ATLEditor Run Window Help G EdBj 0 Q 194 0 B author km3 X package Author class Author attribute name String attribute surname String package PrimitiveTypes datatype String Writable Insert Figure 8 The Author metamodel in KM3 format Note that at this stage the edited KM3 files may include undetected errors Indeed a KM3 file is only compiled when it is the target of an injection operation Now the Author and the Person metamodels have been edited in the KM3 format they can be injected into Ecore files For this purpose select mouse right click Inject KM3 to Ecore metamodel on the Auth
25. ntroduces the transformation example that is going to be developed in the document The aim of this first example is to introduce users with the basic concepts of the ATL programming To this end this example considers two similar metamodels Author Figure 2 and Person Figure 3 that both encode data relative to persons name String surname String Figure 2 The Author metamodel Figure 3 The Person metamodel Both metamodels are composed of a single eponym element Author for the Author metamodel and Person for the Person metamodel Both entities are characterized by the same couple of string properties name and surname The objective is here to design an ATL transformation enabling to generate a Person model from an Author model The transformation to be designed will have to implement the following obvious semantics e A distinct Person element is generated for each source Author element o The name of the generated Person has to be initialized with the name of the source Author o The surname of the generated Person has to be initialized with the name of the source Author Page 2 ATL Documentations VAINRIA ATL Starter s Guide Date 07 12 2005 conforms To conformsTo conforms To Author ecore Person ecore conforms To conforms To conformsTo Author2Person atl Figure 4 Overview of the Author to Person ATL transformation Figure 4 provides an overview of the ATL Author to Person
26. or km3 file see Figure 9 If the file is errorless this operation will create an Author ecore file in the considered project in the Navigator view The Person ecore file can be generated in the same way Page 6 ATL Documentations ATL Starter s Guide Date 07 12 2005 ATL Author km3 Eclipse SDK DER Fie Edit Navigate Search Project ATLEditor Run Window Help rx O Q wP weo EN Bava UN Jalon ias 28 B Outline 3 5 package Author class Author 4n outline is not available attribute name String hte surname String we Author2Person E project Author km3 Open Open With Open As iveTypes S Copy tring E 3 Delete Move Rename 29 Import LA Export E Refresh Run s Debug As Team ties Error Log Console Compare With f Replace With Resource In Folder Location Inject KM3 file to KM3 model Inject KM3 to MOF 1 4 metamodel Inject KM3 to Ecore metamodel Author2Persor Properties Figure 9 Injecting a KM3 file into an Ecore metamodel In case the KM3 source file contains any errors at injection time the Ecore file will not be generated The detected errors will then be located on the edition view when opened and detailed in the Problems view at the bottom of the perspective As an example Figure 10 provides a screenshot of an injection error where the data type of the attribute surna
27. pen With menu see Figure 12 The editor displays an empty textual file Ecore is based on the XMI 2 0 5 XML language As a consequence the first line must include a generic XML header providing versioning and encoding information lt xml version 1 0 encoding ISO 8859 1 gt Next step consists in specifying the root XMI tag This tag will contain the different Author elements of the input model It specifies versioning as well as namespace information Take care here to correctly specify the path to the related Author metamodel lt xmi XMI xmi version 2 0 xmlns xmi http www omg org XMI xmlns Author gt Page 9 Date 07 12 2005 ATL Documentations ATL Starter s Guide ATL Eclipse SDK File Edit Navigate Search Project ATLEditor Run Window Help E Qa B Outline 23 a 4n outline is not available B project ES Project Authored Seine 2 Author kn Open in New Window O ATL Project gt Personel ATL File En Copy Person kr iB Pe XK Delete Move FS Other Ctrl Rename gy Import e Export E Refresh Close Project Run As Debug As roperties Error Log Console Team infos Compare With Resource In Folder Locatic Restore from Local History PDE Tools Author2P Properties Figure 13 Creation of new ATL file As a last step the element of this Author model can be entered within the XMI tag Each entit
28. rder to complete the launch configuration the user must specify a path for each element of the Path Editor table A path can be specified through different means e The Set path button enables to select a file that belongs to a currently opened project e The Set external path button enables to select a file from the file system e The Metamodel by URI button enables to select a metamodel that have been already loaded by an EMF plug in e The MM Is MOF 1 4 button enables to set the metamodel to MOF 1 4 using the version loaded by the ATL engine e Finally the MM is Ecore button enables to set the metamodel to Ecore Page 15 ATL Documentations INRIA ATL Starter s Guide Date 07 12 2005 Warning none model or metamodel is registered Create manage and run configurations Q Configurations Name Author2Person E ATL Transformation New_configuration Eclipse Application E Java Applet IN pour fF Java Application Model Meta Model i Meta Model Ju JUnit Ju JUnit Plug in Test En SWT Application ATL Configuration O Model Choice E Common Model Meta model Add Meta model Add IN Author Person Remove Remove Path Editor Model _ Path Model Ha MOR IN Author2Personjauthors ecore EMF Author Author2Per ecore EMF out Author2re Ecore my Select Model Handler Set path Person Author2Per EMF Set path Set external path Set ext
29. rmation that is required to execute an ATL transformation This mainly includes the path of the files involved in the transformation the transformation file the input and output models the input and output metamodels the libraries In order to create a new launch configuration select the Run item in the Run menu of the Eclipse window see Figure 17 This opens a new Run window Select here the ATL Transformation item in the left column and click on New to create a new ATL launch configuration The ATL launch configuration window see Figure 18 is composed of three distinct tabs ATL Configuration Model Choice and Common In the top of the configuration window the user has to enter the name of the created configuration 8 1 Configuring the ATL Configuration tab The ATL launch configuration window see Figure 18 is composed of three distinct tabs ATL Configuration Model Choice and Common The ATL Configuration tab enables to specify the project that contains the transformation to be executed and the path of the ATL transformation file The considered project is here the Author2Person project and the path of the designed ATL transformation is Author2Person Author2Person ail Page 14 ATL Documentations INRIA ATL Starter s Guide Date 07 12 2005 Create manage and run configurations Configurations Name Author2Person ATL Transformation New_configuration OPETE s Or Application att configurat
30. s been created next step is to provide the ATL tool suite with a computable version of the considered metamodels This new step is detailed in the following section 5 Designing a new metamodel As highlighted in Section 2 it is required for a model transformation to run to have the metamodels of both source and target models which are here respectively Author and Person At this stage these metamodels are only available under a graphical form see Figure 2 and Figure 3 It is therefore necessary to provide the transformation engine with a computable version of these metamodels Page 4 ATL Documentations ATL Starter s Guide E ATL Eclipse SDK TER Fie Edit Navigate Search Project ATLEditor Run Window Help 0 Q E Qan ara Fos LASA O pz Outline 3 5 An outline is not available ES Project an rie gg Import TF Other Ctri N r Export Refresh Si Problems 2 Properties Error Log Console D errors O warnings O infos Description Resource In Folder Location Figure 6 Creation of a new ATL project EMF provides its own file format ecore for model and metamodels encoding This format is based on the semantics of the Ecore metamodel 3 and the corresponding files are encoded with XMI 2 0 5 Although possible the manual edition of Ecore metamodels is particularly difficult with EMF In order to make this common kind of edit
31. t models Although this feature is out of the scope of this document it may be noted that as the entered values represent variable names each of them must be unique within the set of declared models The last step is to specify the name of the libraries that will be required for the transformation to run The design of the current transformation does not require any specific library see the ATL User Manual for further details 7 The creation of the ATL file can then be validated by clicking on Finish As a result of the ATL File Wizard a transformation ATL file Author2Person atl is created in the ATL project This file contains the code of the ATL transformation The ATL editor can be opened by double clicking on the ATL file Figure 15 presents a screenshot of the edition of the Author2Person atl file An ATL module e g an ATL transformation always starts by a module header This header corresponds to the declaration of the module name line 1 followed by the declaration of the input and output models with their respective metamodels line 2 When an ATL file is edited with the ATL editor the Outline view right column provides an overview of the content of the edited file At this stage the outline only displays a Module element named Author2Person for which two OclModel elements e g two models named IN and OUT are defined Besides the transformation file the ATL File Wizard creates an additional new file the transformat
32. y of the input model here corresponds to an empty Author tag with two XMI attributes encoding the name and the surname of Author entity An example of input model is provided in Appendix A Now the input Ecore model has been edited it can be explored with the graphical Ecore Model Editor For this purpose select Sample Ecore Model Editor in the mouse right click gt 0penWith menu Be sure when trying to open a file with an editor that this file is not being edited with another editor At this stage both the metamodels and the input model involved in the transformation to be designed are available under the Ecore computable format It is now possible to focus on the design the ATL transformation itself 7 Programming my first ATL transformation This section aims to guide the ATL user through the programming of its first ATL transformation For this purpose it introduces the basic ATL concepts that are required in the scope of the considered example An exhaustive reference to the ATL transformation language can be found in the ATL User Manual 7 First step in the design of the ATL transformation is the creation of the ATL transformation file For this purpose the ATL Development Tools includes a wizard dedicated to the creation of transformation files Once the file is created the code of the transformation has to be specified 7 1 Creation of the ATL file The ATL file creation wizard is called by selecting New gt ATL File as shown in F
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