Timely – A Domain Specific Language Extension of HTML to Visualize and Query Time Series Data using W3C Web Components

We have developed Timely, a domain specific extension of HTML, that enables the visualization, analysis and subsequent export of metadata-enriched time series data within arbitrary websites. The implementation is based on the W3C standard Web components, so that the extension can be used in all current browsers without installing additional plugins. Web components are user-defined HTML elements that are implemented as JavaScript classes and executed in the user’s browser. They can then be used like normal HTML elements such as table, h1, etc. The components can not only have a visual representation but also communicate with backend server processes. A major advantage of this approach is that the web components developed in this way offer website developers a simple yet powerful declarative interface for implementing their functionality, enabling even non-programmers to create and customize simple web applications according to their needs. The developed components allow flexible querying and presentation of time series data in graphical or tabular form. Furthermore, metadata from InfluxDB, such as all available databases, associated measurements (a data structure typically called table in other database systems) and their structures, can be read out and visualized. ... mehrLike normal HTML elements, web components can be parameterized using attributes. A key feature of our components is the communication between components and their dynamic behaviour in response to changes. When specifying attribute values, property values of other elements can be integrated, which are then monitored for changes. If the value of a property embedded in an attribute value changes, the component is informed and can respond appropriately, for example by executing a new query or adjusting the representation of the visualized data. Similarly, child components are informed of state changes by their ancestor elements. This allows users to easily develop interactive HTML pages for visualising and exporting time series data.