An ADM-based Method for Migrating CMS-based Web Applications: Extracting ASTM Models from PHP Code

In recent years, Architecture-Driven Modernization (ADM) is gaining increasing acceptance in software reengineering processes of existing systems. It can help reduce reengineering costs by automating the activities, such as extracting models from the source code. This is specially crucial in the reengineering of CMS-based Web applications. At time of writing there are no methods that could be used in that context. Hence, we define an ADM-based method for migrating CMS-based Web applications. In the context of this method, we present in this paper the implementation of the text-to-model (M2T) transformations to extract models from PHP code. These models conform to Abstract Syntax Tree Metamodel (ASTM) a standard metamodel proposed by ADM. To implement these transformations we performed three activities: 1) definition of a PHP grammar, 2) mapping PHP grammar elements to elements of ASTM and 3) implementation of a model extractor. To show the feasibility of our approach we use a real example of PHP code from a CMS-based Web application implemented in Drupal.