Exploring (Meta-)Model Snapshots by Combining Visual and Textual Techniques

One central task in software development by means of graph-based techniques is to inspect and to query the underlying graph. Important issues are, for example, to detect general graph properties like connectivity, to explore more special features like the applicability of left-hand side rules in graph transformations, or to validate snapshots of evolving systems by checking properties in an on-the-fly way. We propose a new approach combining visual and textual techniques for exploring graphs. We emphasize a particular aspect of the underlying graph by showing or hiding nodes and edges. We offer three different ways to explore (meta-)model snapshots which may be combined: (1) selection by object identity and class membership, (2) selection by OCL expression, and (3) selection by path length. One main motivation for our work is to access large or complicated graphs in a systematic way. We evaluate our approach by different middle-sized scenarios. Our evaluation shows that the approach works for large graphs with about 1000 nodes and 2000 edges and for graphs which instantiate metamodels representing software engineering artifacts.