Javascript函数本身调用

Question

I want to display a customized alert when i click a but if im logged in i want to redirect to another page. I have this.

        <div id="contentCalendar" class="col-md-3 images_1_of_4 text-center">
            <a><img onClick="show_alert();" id="rotateme" class="img-responsive img-circle center-block" src="web/images/calendaricon.png"/></a>
            <h4><a href="#">Check our last events</a></h4>

        </div>
        <div id="myalert" class="alert alert-error">
        <a href="#" class="close" data-dismiss="alert">&times;</a>
        <strong>Error!</strong> You must be logged in to see our calendar.
        </div>  
        <script>    
        $('#myalert').hide(); 
        //What happen if you want to enter the events without loggin.
        var logged_in = <?php echo ($logged_in); ?>;
        function show_alert()
        {
            if(logged_in==true)
            {
                window.location="timeline.php";
            }
            else
            {
                $('#myalert').show();
            }
        }
        </script>

For some reason works like a charm when Logged_in is true and i get redirected. But when im logged out it just doesnt show the alert even if i didnt press the button at all.

Any ideas?

Answer 1

Always, again, always, run everything you embed in JS through json_encode:

var logged_in = <?php echo json_encode($logged_in); ?>;

When you simply echo a falsy value in php, it echoes nothing, thus breaking your javascript.