Web Engineering Blog

Post date: Monday, July 12, 2021 - 17:02
Updated date: Tuesday, April 5, 2022 - 14:38
Username: gwagner

In this article, we show how to create and clear an IndexedDB database keeping all code in a single HTML file. Creating an IndexedDB database means first creating an empty database, and then adding records to its empty tables (or "object stores"). In Part 2, we will explain how to retrieve, update and delete IndexedDB records, such that we get the full collection of CRUD operations: Create, Update, Retrieve and Delete.

Category: IndexedDB
Post date: Thursday, July 1, 2021 - 14:36
Updated date: Wednesday, July 7, 2021 - 14:54
Username: gwagner

In programming, we often have the situation that, when calling a possibly time-consuming input/output (I/O) operation (or any long-running operation, e.g., for performing a complex computation), the program execution has to wait for its result being returned before it can go on. Calling such an operation and waiting for its result, while the main program's further execution (and its entire thread) is blocked, represents a synchronous operation call.

Category: JavaScript
Post date: Monday, August 17, 2020 - 12:02
Updated date: Saturday, August 22, 2020 - 11:36
Username: mdiaconescu

Seeeduino XIAO is a tiny Arduino compatible board based on Microchip's ARM Cortex-M0+ MCU. Measuring just 2x1.7x0.35 cm, it is low power, comes with 11 GPIO pins and a big features pack, thus making it almost perfect for many IoT/WoT projects.

Category: Arduino, IoT, WoT
Post date: Tuesday, April 21, 2020 - 23:16
Updated date: Thursday, April 30, 2020 - 09:45
Username: gwagner

There have been many articles about the new language elements introduced to JavaScript by ECMAScript 2015+ (that is, 2015+16+17+18+19+20+...). Typically, in these articles, a great number of new features are presented without taking their relevance into consideration, often with artificial programming examples that do not help to exhibit the potential use of a new feature.

In this post, we only present the most important new language elements, which are generally useful for all kinds of basic programming tasks, in a summarized way.

Post date: Tuesday, May 14, 2019 - 22:49
Updated date: Tuesday, May 14, 2019 - 22:56
Username: gwagner

We show how to deal with key-value pairs and how to manage a key-value store using JavaScript's localStorage API.

Post date: Thursday, July 12, 2018 - 13:28
Updated date: Thursday, July 12, 2018 - 13:30
Username: gwagner

For quite a long time, it was pretty cumbersome to delete a node from the DOM of an HTML document because one had to go to its parent and ask it to destroy its child (by invoking removeChild), like so:

  var elemToDrop = document.getElementById("elemID");
  elemToDrop.parentNode.removeChild( elemToDrop);

It has always felt strange having to use such an indirect approach (having to ask the parent) for the very basic operation of dropping a DOM node.

Post date: Wednesday, June 6, 2018 - 12:41
Updated date: Wednesday, June 6, 2018 - 12:43
Username: gwagner

Apple Inc. is an American multinational corporation that develops consumer information and communication technologies (ICT). Today, it's best known for its vastly popular iPhone.

Post date: Wednesday, October 25, 2017 - 16:27
Updated date: Thursday, October 26, 2017 - 23:30
Username: gwagner

Test the Drag & Drop Mechanism

Category: HTML5
Post date: Wednesday, August 16, 2017 - 23:29
Updated date: Wednesday, August 16, 2017 - 23:38
Username: gwagner

The Resource Description Framework (RDF), together with its extension RDF Schema, is a logical formalism that allows formalizing information models in the form of RDF vocabularies and representing propositional information on the Web, embedded in web pages or in the form of special web data sources. OWL extends RDF by adding many additional language elements for expressing constraints, equalities and derived classes and properties in the context of defining vocabularies. Unfortunately, both RDF and OWL have many usability issues.

Category: Semantic Web
Post date: Monday, June 12, 2017 - 13:56
Updated date: Monday, June 12, 2017 - 14:12
Username: gwagner

book coverWe have published Volume 1 of a new open access online textbook Web Applications with JavaScript or Java. It covers the topics of constraint validation, enumerations and special datatypes.


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