Ph.D. - geht es zur Homepage der Informatik des Fachbereiches 3 ...

Chapter 3. Domain-Specific Modelling
3.1.2. Ecore
Ecore [76, pp. 71-73] is very similar to MOF and uses the Eclipse Modelling Framework
(EMF) [76, pp. 71-73]. EMF is a software framework based on Java, which provides functionality
for model-driven software development. Furthermore, it provides mechanisms for creating new
DSLs and for generating code. Its main disadvantage is are the code generation capabilities,
which are limited to Java source code using the EMF.
Ecore is not explained in this document in detail because its similarity to MOF, which was
already introduced in Subsection 3.1.1.
3.1.3. Extensible Markup Language with Schema Definition
The Extensible Markup Language [96] (XML) with XML Schema Definition (XSD) [42, 70] is
very easy and simple to use for DSM because XSD can be directly used as meta meta model
while the definition in XML describes corresponding meta models. A XML file complying to a
certain Schema Definition is then a model of the meta model [76, p. 74].
An example for an XML file or rather model could be the simple description of a software
class, as shown in Figure 3.10. This example can be taken to explain the most important
1
2
3
4
5
6
7 // do something meaningful
8 iValue++;
9
10
11
Figure 3.10.: XML class description example
elements of XML:
Markup
Content
Tag
All elements starting with < and ending with > are markups. In the example, all
lines are markups except 7 and 8.
Every element that is not markup is content. In the example, the only content are
the lines 7 and 8.
A tag is a markup construct. There are three different tag types:
• start-tag (e.g. in line 1)
• end-tag (e.g. in line 11)
• empty-element-tag (e.g. in line 2)
28