Andrew Poulos wrote:
> I had some code that looked like this
>
> document.querySelectorAll('a[href^="goto"]')
>
> that failed because users were setting the href to cases different from
> the expected case.
The attribute name, or the attribute value?
> I was thinking that this was going to be a PIA to
> resolve till a search revealed that in modern browsers there's a flag to
> make an attribute selector case-insensitive.
>
> So for those don't know here's the simple resolution:
>
> document.querySelectorAll('a[href^="goto" i]')
This is a relatively new feature:
<
https://www.w3.org/TR/selectors-4/#attribute-case>
<
https://caniuse.com/css-case-insensitive>
I would be wary to rely on it on the Internet at this point (the intranet
might be a different case); I would use XPath instead (or as a fallback),
which is better supported:
<
https://dom.spec.whatwg.org/#xpathexpression>
(DOM Level 3 XPath is “retired”: <
https://www.w3.org/TR/DOM-Level-3-XPath/>)
<
https://caniuse.com/document-evaluate-xpath>
With WHATWG DOM and XPath 1.0 (assuming that you mean the attribute value):
const xpathCaseInsensitive = function (name, v) {
return `translate(${name}, '${v.toUpperCase()}', '${v.toLowerCase()}')`;
};
const s = 'goto';
let snapshots = document.evaluate(
`//a[starts-with(${xpathCaseInsensitive('@href', s)}, '${s}')]`,
document.body,
null,
XPathResult.XPathResult.ORDERED_NODE_SNAPSHOT_TYPE
);
/* alternatively (more backwards-compatible):
*
* var snapshots = new Array(snapshots.snapshotLength).keys()
* .map((el, i) => snapshots.snapshotItem(i));
*/
snapshots = [...new Array(snapshots.snapshotLength)].map(
(el, i) => snapshots.snapshotItem(i)
);
If at some point in the future XPath 2.0 will be supported sufficiently,
you can write simpler
let snapshots = document.evaluate(
"//a[starts-with(lower-case(@href), 'goto')]",
document.body,
null,
XPathResult.XPathResult.ORDERED_NODE_SNAPSHOT_TYPE
);
snapshots = Array.from(
new Array(snapshots.snapshotLength),
(el, i) => snapshots.snapshotItem(i)
);
I think this should be posted to <news:comp.lang.javascript> (as well).
Adjust follow-ups if necessary.
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