cookie.js

cookie pure ES5 javascript

    <script>
        function addMonth(d, m) {
            var dates = d.getDate();
            var years = Math.floor( m / 12 );
            var months = m - ( years * 12 );
            if( years ) d.setFullYear( d.getFullYear() + years );
            if( months ) d.setMonth( d.getMonth() + months );
            if( dates == 1 ) {
                d.setDate( 0 );
            } else {
                d.setDate( d.getDate() - 1 );
            }
            return d;
        }
        var oneMonthLater = addMonth(new Date(), 1).toGMTString();
        if (!document.cookie.split(';').some(function(item) {
            return item.trim().indexOf('showStayKeepMessage=') == 0
        })) {
            document.cookie = 'showStayKeepMessage=true; expires='+oneMonthLater+';';
        }
        function openStayKeepMessage() {
            document.cookie = 'showStayKeepMessage=true; expires='+oneMonthLater+';';
            document.querySelector('.StayKeepMessage').classList.remove('closeStayKeepMessage');
            document.querySelector('.StayKeepMessage').classList.add('openStayKeepMessage');
        }
        function closeStayKeepMessage() {
            document.cookie = 'showStayKeepMessage=false; expires='+oneMonthLater+';';
            document.querySelector('.StayKeepMessage').classList.remove('openStayKeepMessage');
            document.querySelector('.StayKeepMessage').classList.add('closeStayKeepMessage');
        }
    </script>
    <button onclick="closeStayKeepMessage()">隠す</button>
    <button onclick="openStayKeepMessage()">開く</button>

    <script>
        if (document.cookie.replace(/(?:(?:^|.*;\s*)showStayKeepMessage\s*\=\s*([^;]*).*$)|^.*$/, "$1") === "true") {
            document.querySelector('.StayKeepMessage').classList.add('openStayKeepMessage');
        } else {
            document.querySelector('.StayKeepMessage').classList.add('closeStayKeepMessage');
        }
    </script>