Uniform Resource Identifiers (URI)
- Lesson title: Uniform Resource Identifiers (URI)
- Keywords: Identifier, PID, URI, IRI
- Objective/Description: In this lesson we will introduce namespaces and Uniform Resource Identifier (URIs) including their use, advantages and integration into XML. We will also discuss Regular Expressions as they will become useful in later lessons.
- Learning outcomes:
- Explaining the characteristics of URIs
- Using namespaces and stating their benefits
- Discussing why URIs and namespaces are needed
- Illustrating via examples how URIs are used in XML docs
- Understanding the uses and advantages of Regular Expressions
- Creating basic Regular Expressions
Resources
Questions and answers
These Q&A aim to validate a basic understanding of concepts discussed during the lecture. The use of such concepts is beyond the scope of this Q&Astudy set as it is addressed via projects and hands-on for those enrolled in the corresponding university course.
Whay are namespaces useful?
Namespaces provide a context so we can group and distinguish XML elements with the same tag. Namespaces allow us to group a set of tags pertaining to a particular domain, e.g., books.
What is a URI?
URI corresponds to Uniform Resource Identifier. It is a subset of the International Resource Identifiers. URIs comprise Uniform Resource Locators (URLs include the access mechanism, e.g., via Internet) and Uniform Resource Names (URNs provide a unique name). URIs provide a unique identity to a resource and can be resolvable to an IP address, e.g., they can be assigned/associated to a URL which can be access directly on the Web.
What is the basic structure of a URI?
A URI contains the schema (e.g., http), the authority (e.g., wikidata). A URI can also contain a port, a path to reach a particular resource within the Authority, a query or a fragement to reach a particular section within a document.
What is a regular expression?
A description language (or syntax) allowing the specification of language patterns. RegEx are efficient ways to find patterns. They are useful to, for instance, find patterns along URIs.