SVG stands for Scalable Vector Graphics. It's an XML-based file format used to describe 2D graphics. SVG allows for the display of vector images that can be scaled to any size without losing quality. It's widely used in web design because it offers high resolution at any size and integrates easily into web pages.
Here are some key features of SVG:
Vector-based: SVG graphics are made up of lines, curves, and shapes defined mathematically, unlike raster images (like JPEG or PNG), which are made of pixels.
Scalability: Since SVG is vector-based, it can be resized to any dimension without losing image quality, making it ideal for responsive designs.
Interactivity and Animation: SVG supports interactivity (e.g., via JavaScript) and animation (e.g., via CSS or SMIL).
Search engine friendly: SVG content is text-based and can be indexed by search engines, offering SEO benefits.
Compatibility: SVG files are supported by most modern web browsers and are great for logos, icons, charts, and other graphics.
SLD (Styled Layer Descriptor) is an XML-based standard developed by the Open Geospatial Consortium (OGC). It is used to define the styling of geospatial data in web mapping services like WMS (Web Map Service).
SLD describes how certain geospatial features should be rendered on a map — meaning it defines colors, lines, symbols, labels, and more. With SLD, you can specify things like:
Roads should appear red.
Water bodies in blue, with a certain transparency.
Points should have symbols that vary depending on attribute values (e.g., population).
Text labels over features.
SLD is an XML file with a defined structure.
It can be read by WMS servers like GeoServer or MapServer.
The file includes Rules, Filters, and Symbolizers like LineSymbolizer, PolygonSymbolizer, or TextSymbolizer.
<Rule>
<Name>Water Bodies</Name>
<PolygonSymbolizer>
<Fill>
<CssParameter name="fill">#0000FF</CssParameter>
</Fill>
</PolygonSymbolizer>
</Rule>To create custom-styled maps (e.g., thematic maps).
To define styling server-side, so the map is rendered correctly regardless of the client.
For interactive web GIS applications that react to attribute values.
If you're working with geospatial data — for example in QGIS or GeoServer — you'll likely come across SLD when you need fine-grained control over how your maps look.
Dynamic HTML (DHTML) is a combination of technologies used to create interactive and dynamic web content. It’s not a standalone standard or programming language but rather a collection of techniques and tools that work together. DHTML enables websites to update content dynamically and provide interactivity without reloading the entire page.
HTML (Hypertext Markup Language)
Provides the basic structure of the webpage.
CSS (Cascading Style Sheets)
Controls the appearance and layout of the webpage. CSS can be dynamically altered to create effects like hover states or style changes.
JavaScript
Adds interactivity and dynamic behavior, such as updating content without a page reload.
DOM (Document Object Model)
A programming interface that allows access to and manipulation of the webpage’s structure. JavaScript interacts with the DOM to change content or add new elements.
Here’s a simple example of a button changing text dynamically:
<!DOCTYPE html>
<html>
<head>
<style>
#text {
color: blue;
font-size: 20px;
}
</style>
<script>
function changeText() {
document.getElementById("text").innerHTML = "Text changed!";
document.getElementById("text").style.color = "red";
}
</script>
</head>
<body>
<p id="text">Original text</p>
<button onclick="changeText()">Click me</button>
</body>
</html>Nowadays, DHTML has been largely replaced by modern techniques like AJAX and frameworks (e.g., React, Vue.js). However, it was a crucial step in the evolution of interactive web applications.
The Document Object Model (DOM) is a standardized interface provided by web browsers to represent and programmatically manipulate structured documents, especially HTML and XML documents. It describes the hierarchical structure of a document as a tree, where each node represents an element, attribute, or text.
Tree Structure:
<html> element, with child nodes such as <head>, <body>, <div>, <p>, etc.Object-Oriented Representation:
Interactivity:
<p> element or insert a new <div>.Platform and Language Agnostic:
1. Accessing an Element:
let element = document.getElementById("myElement");2. Changing Content:
element.textContent = "New Text";3. Adding a New Element:
let newNode = document.createElement("div");
document.body.appendChild(newNode);The DOM is defined and maintained by the W3C (World Wide Web Consortium) standards and is constantly updated to support modern web technologies.
Markdown is a lightweight markup language designed to create easily readable and simultaneously formattable text. It is often used to format text in websites, documentation, and other text-based formats. Markdown files use the .md or .markdown file extension.
Here are some basic elements of Markdown:
Headings:
# Heading 1## Heading 2### Heading 3Text Formatting:
*italic* or _italic_**bold** or __bold__~~strikethrough~~Lists:
* Item 1* Item 21. Item 12. Item 2Links:
[Link text](URL)Images:
Code:
`code`Blockquotes:
> This is a quoteHorizontal Line:
--- or ***Markdown is particularly useful because it is easily readable even when not rendered. This makes it ideal for use in versioning and collaboration systems like GitHub, where users can directly view and edit text files.
XHTML (Extensible Hypertext Markup Language) is a variant of HTML (Hypertext Markup Language) that is based on XML (Extensible Markup Language). XHTML combines the flexibility of HTML with the strictness and structure of XML. Here are some key aspects and features of XHTML:
Structure and Syntax:
<p></p>) or as self-closing tags (e.g., <img />).Compatibility:
Doctype Declaration:
Practical Use:
Different XHTML Profiles:
In summary, XHTML is a stricter and more structured variant of HTML based on XML, offering advantages in certain application areas. It was developed to improve web interoperability and standardization but has not been fully adopted due to the advent of HTML5.
XML stands for "eXtensible Markup Language" and is a widely used language for structuring and presenting data. Essentially, XML is used to organize information in a formatted, hierarchical manner. It's similar to HTML but much more flexible, allowing for the creation of custom tags to label specific types of data.
XML finds applications in various fields such as:
Web Development: Used for data transmission between different systems or configuring web services.
Databases: Facilitates data exchange between different applications or for storing structured data.
Configuration Files: Many software applications use XML files to store settings or configurations.
Document Exchange: Often used to exchange structured data between different platforms and applications.
XML uses tags similar to HTML to organize data. These tags are used in pairs (opening and closing tags) to denote the beginning and end of a particular data component. For example:
<Person>
<Name>Max Mustermann</Name>
<Age>30</Age>
<Address>
<Street>Main Street</Street>
<City>Example City</City>
</Address>
</Person>
Here, a simple XML structure is articlen containing information about a person including name, age, and address.
XML provides a flexible way to structure and store data, making it an essential tool in information processing and data exchange.
PHPStan
