prefill `input[type=url]` field with "http://" upon focus

prefill-url.js

// Prefill URL field with 'http://' upon focus.

$('input[type=url][placeholder="http://"]').on('focus', function (e) {
    var $this = $(this);
    if (!$this.val()) {
        // This `setTimeout` is so we set the value *after* the field has
        // been focussed; otherwise, the text will be highlighted upon focus.
        setTimeout(function() {
            $this.val('http://');
        }, 0);
    }
}).on('blur', function () {
    var $this = $(this);
    if ($this.val() === 'http://') {
        $this.val('').addClass('empty');
        if (!this.hasAttribute('required')) {
            $this.removeClass('focused');
        }
    }
});