Update appended variable on click PHP / Jquery

Question

I have an array like

     <?php 
        $info = array(
            "cat",
            "dog",
            "bear"
            );
    ?>

And I output one String randomly on an overlay like

<script>
var text = '<?php echo $info[array_rand ($info)];?>';

$(function() {

var loading = function() {

    var over = '<div id="overlay">' + '<p class="info">' + text + '</p>' + '</div>';         
    $(over).appendTo('body');

    $('#overlay').click(function() {
        $(this).remove();
    });


    $(document).keyup(function(e) {
        if (e.which === 27) {
            $('#overlay').remove();
        }
    });
};

$('.wrapper').click(loading);

});
</script>

CSS:

#overlay {
position: absolute;
left: 0;
top: 0;
bottom: 0;
right: 0;
background: #000;
opacity: 0.90;
height: 200%;
}

.info{
position: absolute;
width: 100%;
top: 25%;
height: 200px;
font-size: 50px;
color: white;
text-align: center;
}

My question is: How can I update the var text and get a new random string every time the overlay is opened by clicking on the body? Till now the string in var text is only updated when I reload the whole page.

Thanx :)

Answer 1

Print your PHP array in the page using JSON:

<!-- language: lang-php -->

<?php
$info = array(
            "cat",
            "dog",
            "bear"
            );
?>

<!-- language: lang-js -->

<script type="text/javascript">
// (it's better to retrieve it in ajax)
var arr = <?php echo json_encode($info); ?>;

//  2. Roll some dice in Javascript
// Math.random returns a random value between 0 and 1
var text = "";
// wrapped in a function so you can pick new random values
function pickRandom() {
    // Math.random returns a decimal number, and you need to access arrays using their indexes (0, 1, 2) not decimal numbers. Number.parseInt does the rounding.
    text = arr[ Number.parseInt( Math.random()*arr.length ) ];
    alert("new random value is: " + text);
}
pickRandom();
</script>

Then the rest of your code should work. Hope this helps.

Doc:

• JSON encoding: http://php.net/manual/fr/function.json-encode.php
• JS randomness: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/random

Answer 2

You cannot because PHP is executed on the server side.

When you load the page, it sends to your browser the final HTML, with the result of <?php echo $info[array_rand ($info)];?>.

If security is not an issue (games, banking...) you can use randomness using JavaScript.

Otherwise you can reload the page manually like so:

$('#overlay').click(function() {
    // reload the page silently. see also http://stackoverflow.com/questions/2624111/preferred-method-to-reload-page-with-javascript
    window.location.href = window.location.href;
    //$(this).remove();
});