Composing JSON-based Web APIs

International audienceThe development of Web APIs has become a discipline that companies have to master to succeed in the Web. The so-called API economy is pushing companies to provide access to their data by means of Web APIs, thus requiring web developers to study and integrate such APIs into their applications. The exchange of data with these APIs is usually performed by using JSON, a schemaless data format easy for computers to parse and use. While JSON data is easy to read, its structure is implicit, thus entailing serious problems when integrating APIs coming from di erent vendors. Web developers have therefore to understand the domain behind each API and study how they can be composed. We tackle this issue by presenting an approach able to both discover the domain of JSON-based Web APIs, and identify composition links among them. Our approach allows developers to easily visualize what is behind APIs and how they can be composed to be used in their applications

Towards a Generic Method for Articulating Design Uncertainty

Modelers encounter different kinds of uncertainty in their designs and models of software systems. One such type concerns uncertainty about how to build a model. This is called design-time uncertainty, and existing research has studied how modelers can work in its presence. However, the process by which they come to elicit and express their uncertainties remains unclear. In this paper, we take steps towards addressing this gap by introducing DRUIDE (Design and Requirements Uncertainty Integrated Development Environment), a language and workflow for articulating design time uncertainty. We present and illustrate our proposal on a software design example. Additionally, we conduct a real life case study of domain analysis related to the uncertainty caused by the COVID-19 pandemic, and evaluate DRUIDE with it. Our evaluation shows that DRUIDE is sufficiently expressive to articulate design time uncertainty

Applying model transformation and Event-B for specifying an industrial DSL

In this paper we describe our experience in applying the Event-B formalism for specifying the dynamic semantics of a real-life industrial DSL. The main objective of this work is to enable the industrial use of the broad spectrum of specification analysis tools that support Event-B. To leverage the usage of Event-B and its analysis techniques we developed model transformations, that allowed for automatic generation of Event-B specifications of the DSL programs. The model transformations implement a modular approach for specifying the semantics of the DSL and, therefore, improve scalability of the specifications and the reuse of their verification. Keywords: domain specific language, Event-B, model transformations, verification and validation, reuse, scalabilit

2D Corrugated Magnesium Carboxyphosphonate Materials: Topotactic Transformations and Interlayer “Decoration” with Ammonia

In this paper we report the synthesis and structural characterization of the 2D layered coordination polymer Mg­(BPMGLY)­(H₂O)₂ (BPMGLY = bis-phosphonomethylglycine, (HO₃PCH₂)₂N­(H)­COO^2–). The Mg ion is found in a slightly distorted octahedral environment formed by four phosphonate oxygens and two water molecules. The carboxylate group is deprotonated but noncoordinated. This compound is a useful starting material for a number of topotactic transformations. Upon heating at 140 °C one (of the two) Mg-coordinated water molecule is lost, with the archetype 2D structure maintaining itself. However, the octahedral Mg in Mg­(BPMGLY)­(H₂O)₂ is now converted to trigonal bipyramidal in Mg­(BPMGLY)­(H₂O). Upon exposure of the monohydrate Mg­(BPMGLY)­(H₂O) compound to ammonia, one molecule of ammonia is inserted into the interlayer space and stabilized by hydrogen bonding. The 2D layered structure of the product Mg­(BPMGLY)­(H₂O)­(NH₃) is still maintained, with Mg now acquiring a pseudo-octahedral environment. All of these topotactic transformations are also accompanied by changes in hydrogen bonding between the layers