40 lines
1.4 KiB
Markdown
40 lines
1.4 KiB
Markdown
# Accessible Charts
|
|
|
|
Chart.js charts are rendered on user provided `canvas` elements. Thus, it is up to the user to create the `canvas` element in a way that is accessible. The `canvas` element has support in all browsers and will render on screen but the `canvas` content will not be accessible to screen readers.
|
|
|
|
With `canvas`, the accessibility has to be added with ARIA attributes on the `canvas` element or added using internal fallback content placed within the opening and closing canvas tags.
|
|
|
|
This [website](http://pauljadam.com/demos/canvas.html) has a more detailed explanation of `canvas` accessibility as well as in depth examples.
|
|
|
|
## Examples
|
|
|
|
These are some examples of **accessible** `canvas` elements.
|
|
|
|
By setting the `role` and `aria-label`, this `canvas` now has an accessible name.
|
|
|
|
```html
|
|
<canvas id="goodCanvas1" width="400" height="100" aria-label="Hello ARIA World" role="img"></canvas>
|
|
```
|
|
|
|
This `canvas` element has a text alternative via fallback content.
|
|
|
|
```html
|
|
<canvas id="okCanvas2" width="400" height="100">
|
|
<p>Hello Fallback World</p>
|
|
</canvas>
|
|
```
|
|
|
|
These are some bad examples of **inaccessible** `canvas` elements.
|
|
|
|
This `canvas` element does not have an accessible name or role.
|
|
|
|
```html
|
|
<canvas id="badCanvas1" width="400" height="100"></canvas>
|
|
```
|
|
|
|
This `canvas` element has inaccessible fallback content.
|
|
|
|
```html
|
|
<canvas id="badCanvas2" width="400" height="100">Your browser does not support the canvas element.</canvas>
|
|
```
|