Use "accept" attribute on file inputs to limit file selection to extensions allowed by the field

[Toutouwai]

File and image fields have a setting to define the allowed file extensions:

It would be helpful if the file <input> in the inputfield applied any allowed extensions in an accept attribute, so that the OS will filter out files with invalid extensions when browsing for a file to upload.

[Toutouwai]

A hook for the time being:

$wire->addHookBefore('InputfieldFile::render', function(HookEvent $event) {
    /** @var InputfieldFile $inputfield */
    $inputfield = $event->object;
    if(!$inputfield->extensions) return;
    $extensions = array_filter(explode(' ', $inputfield->extensions));
    $inputfield->attr('accept', '.' . implode(',.', $extensions));
});