The preserveAspectRatio read-only property of the SVGPatternElement interface reflects the preserveAspectRatio attribute of the given element. It defines how the pattern's content should be scaled to fit the given space, preserving its aspect ratio.
An SVGAnimatedPreserveAspectRatio object.
Given the following SVG, we can use the preserveAspectRatio property to retrieve the scaling behavior for the pattern element:
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 200 200">
<defs>
<pattern
id="pattern1"
width="10"
height="10"
preserveAspectRatio="xMidYMid meet">
<circle cx="5" cy="5" r="5" fill="blue" />
</pattern>
</defs>
<rect x="0" y="0" width="100" height="100" fill="url(#pattern1)" />
</svg>We can access the preserveAspectRatio attribute:
const pattern = document.querySelector("pattern");
console.log(pattern.preserveAspectRatio.baseVal); // output: SVGPreserveAspectRatio {align: 1, meetOrSlice: 1}