$.expr[':'].containsCaseInsensitive = function (n, i, m) {
return jQuery(n).text().toUpperCase().indexOf(m[3].toUpperCase()) >= 0;
};
.expr isn't defined.
I have added a CDN just incase
<script src="https://cdnjs.cloudflare.com/ajax/libs/sizzle/2.2.1/sizzle.js"></script>
Cant see why expr would not be defined if the script is included in the header?
Error Being:
Uncaught TypeError: Cannot read properties of undefined (reading 'expr')
In jQuery 1.8 the API for this changed, the jQuery 1.8+ version of this would be:
jQuery.expr[":"].Contains = jQuery.expr.createPseudo(function(arg) {
return function( elem ) {
return jQuery(elem).text().toUpperCase().indexOf(arg.toUpperCase()) >= 0;
};
});