To make a device or a service compatible with Node-RED, a native Node.js library capable of talking to the particular device or service is required. Lastly, the learning curve to develop a new node for the platform is low for Node.js developers since a node is simply an encapsulation of Node.js code.
Mashup definition software#
Indeed, new nodes for interacting with new hardware, software and web services are constantly being added, making Node-RED a very rich and easily extensible system. Since in Node-RED nodes are blocks of JavaScript code, it is-technically-possible to wrap any kind of functionality and encapsulate that as a node in the platform. Sub-flows allow creating composite nodes encompassing complex logic represented by internal data flows. There is a new concept of “sub-flows” that is being introduced into the world of Node-RED. in order to be imported anew to Node-RED or shared online. Node-RED flows are represented in JSON and can be serialized, e.g.
Mashup definition code#
Hence, with Node-RED the time and effort spent on writing boilerplate code is greatly reduced, and the developer can focus on the business logic of the application.
Mashup definition serial#
In contrast, to use a serial port in Node-RED, all a developer has to do is to drag on a node and specify the serial port details.
to access the temperature data from a sensor connected to a device's serial port or to manage authentications using OAuth, is typically large. The amount of boilerplate code that the developer has to write to wire such different systems, e.g. IoT solutions often need to wire different hardware devices, APIs, online web services in interesting ways. After connecting many such nodes, the final diagram is called a flow. Two nodes can be wired together by connecting the output port of a node to the input port of the other node. Additional blocks (nodes) can be placed in between these components to represent software functions that manipulate and transform the data during its passage. A node is a visual representation of a block of JavaScript code designed to carry out a specific task. Node-RED provides a GUI where users drag-and-drop blocks that represent components of a larger system which can either be devices, software platforms or web services that are to be connected. It uses an event-driven, non-blocking I/O model suited to data-intensive, real-time applications that run across distributed devices. It is based on the server side JavaScript framework Node.js 2 (that is the “Node” in its name). Node-RED 1 is an open-source mashup tool developed by IBM and released under Apache 2 license. In this section, we detail on the most prominent mashup tools available. Using this web-mashup application, the following sections introduce different requirements scenarios that help analyze (self)adaptation concepts and reference models.Ĭhristian Prehofer, Ilias Gerostathopoulos, in Managing the Web of Things, 2017 3.3 State of the Art in Mashup Tools Finally, it uses this location to obtain the corresponding weather information through the weather service. Once obtained, this profile uses the XML Twitter profile decoder component ( Decoder) to obtain the registered location as a city-country pair. To exchange information among them, components communicate either by wiring directly their respective interfaces, or by binding their interfaces through communication protocols such as SOAP, RMI, JMS, or REST.įor a given user (the userId exposed property in the figure), the Twitter-Weather mashup component ( TWMashup) requests the user profile from Twitter using the twitter service. Components can contain other components hierarchically (thus called composites) and can be implemented using different programming constructs and languages. The fundamental concept of SCA is the notion of component, a gray-box software artifact with well-defined provided interfaces (or services), required interfaces (service references), and exposed properties. The Twitter-Weather web-mashup application architecture.
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