Binds a D3.js gauge or bullet chart to MAIDR, generating the accessible data
representation.
Point selector at the mark that moves with the value — the needle, the
value arc, the bullet's measure bar. Only the first match is read: a gauge
draws exactly one measure, which is why its payload is a single object
rather than an array of one.
min and max are required because the value alone is not the reading.
"73" means nothing without the range it sits in, the target it was aiming
at, and the band it lands in — and a sighted reader takes all three from the
dial's geometry, which is exactly what a screen reader cannot reach.
A D3BinderResult with the MAIDR data and generated layer.
Remarks
Timing — call after D3 has rendered. Like every D3 binder, this reads
the matched element's D3-bound __data__; calling it before
.data().join() has run (or before the SVG is mounted) throws "No elements
found for selector …" or "Property '…' not found on datum".
Binds a D3.js gauge or bullet chart to MAIDR, generating the accessible data representation.
Point
selectorat the mark that moves with the value — the needle, the value arc, the bullet's measure bar. Only the first match is read: a gauge draws exactly one measure, which is why its payload is a single object rather than an array of one.minandmaxare required because the value alone is not the reading. "73" means nothing without the range it sits in, the target it was aiming at, and the band it lands in — and a sighted reader takes all three from the dial's geometry, which is exactly what a screen reader cannot reach.