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.
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.
There have been many articles about the new language elements introduced to
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
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
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");
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.
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.