Model-to-model transformation

Exercise 1: Study this ETL transformation, which demonstrates generating multiple output elements from a single source element. Modify this ETL transformation on Epsilon’s Playground so that it generates 2 deliverables per task:

• One interim report halfway through the task
• One final report at the end of the task

Exercise 2: Study this Flock migration transformation on Epsilon’s Playground. Now complete this Flock migration to add effort elements to the migrated model.

Note

The names of the original and migrated models in the Flock transformation of Exercise 2 are Original and Migrated respectively. Therefore, to create a new Effort element in the migrated model you can use var effort : new Migrated!Effort;.

Note

You can develop the transformations above either directly on the Playground or in Eclipse, as demonstrated in the respective lectures. If you develop them on the Playground, we advise you to also download copies (using the Playground’s Download -> Ant (Eclipse) menu and dialog) and run them within Eclipse.

Exercise 3

Write a M2M transformation with ETL that produces a MiniVoiceXML model from a call centre model. MiniVoiceXML is a toy version of the W3C VoiceXML specification.

MiniVoiceXML metamodel

• A Document has 0+ Dialogs, which can be Forms or Menus: execution starts from first Dialog
• A Form has 0+ FormItems: Form gets inputs from the caller and assigns them to variables
  • Field: prompt the caller, read line of input, and assign input to var with given name
  • Transfer: transfer the caller to another number (dest uses tel:NUMBER)
  • Block: 0+ executable elements
    • GoTo: switch to another Dialog
    • Prompt: output text to user
• A Menu has a Prompt and 1+ Choice: runs the Prompt then shows options and waits for choice
  • dtmf: number (1-9) to be typed by caller
  • next: Dialog to traverse to if chosen

The transformation

• Clone this Github
  • Alternatively, download a copy of its contents
• Import the metamodel project (minivoicexml) into Eclipse
• In a nested Eclipse, import the interpreter (minivoicexml.interpreter) project
• In the nested Eclipse, create a new project named callcentre2minivoicexml
• In the new project, create an ETL script with these rules:
  • Model → Document with the Dialogs produced from the Steps
    • The first Dialog should be the one from the first Step that would be run
  • Statement → Form with Block containing a Prompt
  • CallRedirection → Form with Transfer (watch out for dest format)
  • InputQuestion → Form with Field containing a Prompt
  • Decision → Menu with Prompt
  • Transition →
    • If the source is a Decision: add Choice to the Menu from the source node
      • Remember to set the dtmf, text, and next features correctly!
    • Any other: add GoTo to the Block at the end of the Form from source node
      • If such a Block does not exist, add it as well
      • Remember to set the next reference to the equivalent of the Transition target
• Run your ETL script on your sample model:
  • Configure the launch so the new model is saved to generated-voicexml.model inside your callcentre2minivoicexml project
• Run the resulting MiniVoiceXML models on the interpreter:
  • In minivoicexml.interpreter, right-click on Launcher.launch, select Run As –> Launcher
  • The interpreter will run from the Console view: check that the model behaves as expected by entering your answers

Solutions

• Exercise 1

rule Project2Project
	transform s : Source!Project
	to t : Target!Project {

	t.name = s.name;

	// Transform the tasks of the source
	// project using the Task2Deliverable
	// rule and assign the result to
	// t.deliverables
	t.deliverables ::= s.tasks;
}

// Transform each task to two deliverables
// to be submitted in the middle and at the end of the task
rule Task2Deliverable
	transform t : Source!Task
	to interim : Target!Deliverable, 
       final : Target!Deliverable {

	interim.name = t.name + " Interim Report";
	interim.due = t.start + (t.duration / 2);

	final.name = t.name + " Final Report";
	final.due = t.start + t.duration;

	// The lead of the deliverables
	// is the person with the highest
	// effort in the task
	var lead = t.effort.sortBy(e|-e.percentage).
		first()?.person;

    interim.lead ::= lead;
    final.lead ::= lead;
}

// @lazy means that persons will be transformed 
// only upon request. As such, Charlie will not 
// appear in the target model because he leads
// no deliverables
@lazy
rule Person2Person
	transform s : Source!Person
	to t : Target!Person {

	t.name = s.name;
}

• Exercise 2: A reference solution is available on Epsilon’s playground.
• Exercise 3: A reference solution is available on Epsilon’s playground.