1959416 - Estimate usage of anchor positioning with different CSS layout models

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, task)

Description

[Jari Jalkanen]

To better understand the demand for anchor positioning with different layout choices, we can

• estimate the current use of the feature in grid/flexbox/table/normal layouts
• find out which of the most often visited online properties rely on anchor positioning and how?

Comment 1

[Jari Jalkanen]

Summary of results based on queries from httparchive:

In average, out of pages on which Blink feature Anchor Positioning is detected

• With CSSFlexibleBox 2107/2137 ~ 98.6 %
• With CSSGridLayout 1092/2137 ~ 51 %
• With CSSGridLayout only 4/2137 ~ 0.19 %
• Neither 26/2137 ~ 1.2 % (!)

For reference, out of all pages in the same crawl [2],

• With CSSFlexibleBox 11581430/13185550 ~ 88 %
• With CSSGridLayout 4201451/13185550 ~ 32 %
• With CSSGridLayout only 20699/13185550 ~ 0.15 %
• Neither 1583421/13185550 ~ 12 % (!)

All use also normal block layouts
Table usage is low (or nonexistent)

Note:
Turns out that when a page is exported on a mobile client, all: unset gets expanded into explicit resets for many CSS properties, leading to anchor-name: none and position-anchor: auto definitions. For example, many sites using Feedbackify appear to have this issue, leading to false positives.