Question

I have this:

<script type="text/javascript">
var dataset = [ 5, 10, 15, 20, 25 ];

        d3.select("body").selectAll("p")
            .data(dataset)
            .enter()
            .append("p")
            .text("New paragraph!");
</script>

It works. Then I’ve been learning MySQL/PHP and have some data in a tiny database.

<?php
if ( $results ) {
foreach($results as $row) {
    echo $row->eventName . "<br>";
}
} else {
echo 'No rows found.';
}
?>

That works with the rest of it and displays some random event names like Movies, Shopping, Work.

I found this tutorial on how to bring PHP variables into Javascript but can’t figure it out. To simplify instead of trying to figure out the array I even switched to just trying to figure out the data itself but couldn’t even get that. This is what my last attempt was:

    <?php
$php_var = 1;
?>

<script type="text/javascript">
var dataset = <?php echo $php_var; ?>

        d3.select("body").selectAll("p")
            .data(dataset)
            .enter()
            .append("p")
            .text("New paragraph!");
</script>

And then I thought maybe an array would work so tried this

<?php
$php_var = array(
    5, 10, 15, 20, 25);
?>

<script type="text/javascript">
var dataset = $php_var

        d3.select("body").selectAll("p")
            .data(dataset)
            .enter()
            .append("p")
            .text("New paragraph!");
</script>

But also had no luck. Could anyone offer me some advice or point me towards a tutorial on how to get data from PHP into Javascript?

Answer 1

Try using PHP’s json_encode function, and then embedding the data:

<?php
    $dataset = array(5, 10, 15, 20, 25);
?>
<script>
    var dataset = <?php echo json_encode($dataset); ?>;
    // ...
</script>