Creating SVG Graphics
Important to Note: SVG is XML-based, which sets it apart from HTML5 as explained in this source. In SVG, quoted values for attributes are required unlike the unquoted attribute syntax allowed in HTML5.
It's crucial to always specify the namespace (
xmlns="http://www.w3.org/2000/svg"
) when working with SVG images to ensure proper rendering and recognition by browsers.
Additionally, containing your graphics within the visible region defined by the viewBox attribute is essential. Anything outside this view will not be visible due to clipping.
Creating a Venn Diagram
For static diagrams like Venn diagrams, positioning elements statically inside the viewBox is sufficient. This eliminates concerns about animations moving elements out of view unintentionally.
To create Venn diagrams, position and colorize the shapes using <circle> and <text> elements within the viewBox.
Utilize <g> (group) elements to set inherited attributes efficiently and avoid duplication on individual elements.
CSS can be used to add color effects to intersections in the diagram rather than using more complex methods like clipPath or paths for each segment.
Incorporating External Text
The text labels for circles ("PR", "Ki67", "ER") should be positioned within the viewBox for visibility. Adjust the viewBox size accordingly to encompass these labels.
Position the title ("% of Positivity") at the top left corner of the viewBox and include an accessible name using the <title> element.
Moving font-related attributes (font-family, font-size) to a common ancestor (<svg>) allows them to be inherited by new <text> elements under it.
Defining the preferred size of the SVG using the width and height attributes ensures consistent display across different devices while preserving aspect ratio based on the viewBox.
Integrating SVG in HTML
SVG images can be embedded directly in HTML or as external resources using the img element.
When embedding externally, remember that the browser renders only visuals, losing text content. Providing alternative text using the alt attribute is crucial for accessibility.
- Add a text alternative for the image with the
alt attribute.
- Include width and height attributes if needed to prevent layout shifts.
- Optionally, assign a title matching the SVG's
<title> content using the title attribute.
Example of embedding an SVG with img:
<img width="600" height="480"
src="/percentage-of-positivity.svg"
title="Percentage of Positivity"
alt="Description of image here.">
Consider white-space in the alt attribute for better presentation consistency.
Adding a Caption: Utilize the <figcaption> element for captions alongside figures.
Note: Titles and captions serve distinct purposes in documenting visual content accurately.