Highcharts data series issue with ajax/json and PHP

This is my first request here, and I've read many of the other related posts on this same issue, but I'm STILL getting stuck and pretty much at my wits end on this... So any help is much appreciated!

I've got the following Highcharts object on Page1.php, and I'm using AJAX to get data from Page2.php on page load as well as when a dropdown option is changed.

(truncated for ease of reading):

$(document).ready(function() {

   var e = document.getElementById("selOption"); //<--- This is the dropdown
   var domText = e.options[0].text;
   var domID = e.options[e.selectedIndex].value;

   var options = {
      chart: {
         renderTo: 'linechart',
         type: 'line'
      },
      title: {
         text: 'Title for ' + domText
      },
      subtitle: {
         text: ''   
      },
      xAxis: {
         type: 'datetime',
         dateTimeLabelFormats: {
            month: '%b %e, %Y',
            year: '%Y'
         }
      },
      yAxis: {
         title: {
            text: 'Important Values'
         },
         reversed: true,
         min: 0,
         max: 100
      },
      tooltip: {
         formatter: function() {
                   return '<b>'+ this.series.name +'</b><br/>'+
               Highcharts.dateFormat('%b %e', this.x) +': '+ this.y;
         }
      },
      series: []

};

$.get('Page2.php?domID=' + domID,function(data) {
    $.each(data, function(key,value) {
        //var series = {};
        //series.name.push(value);
        //series.data.push([value]);
        options.series.push(data);
        //alert(data);
    });

    var linechart = new Highcharts.Chart(options);
});

});

Page2.php has the following sending back the json:

$sqlSelect = "SELECT Item1,Item2,Item3 FROM... ";
$result = mysql_query($sqlSelect);

while ($item = mysql_fetch_assoc($result)) {            
    $name = $item['Item1'];
    $date = str_replace("-",",",$item['Item2']);

Since Javascript UTC method will return with an Integer, it's just better if you just pass the Unix Timestamp as an integer when you're generating the JSON on the serverside instead trying to pass a function (UTC.Date) in the JSON - that makes the entire JSON invalid!

Instead of this

while ($item = mysql_fetch_assoc($result)) {            
    $name = $item['Item1'];
    $date = str_replace("-",",",$item['Item2']);
    $pos = $item['Item3'];

    $arr = array("name"=>$name,"data"=>"[Date.UTC(".$date."), ".$pos." ],");
    echo json_encode($arr);         
}

Do this:

while ($item = mysql_fetch_assoc($result)) {            
    $name = $item['Item1'];
    $unix_date = date("Y-m-d", strtotime($item['Item2']));
    $pos = $item['Item3'];

    $arr = array("name"=>$name,"data"=>"[".($unix_date*1000).", ".$pos." ],");
    echo json_encode($arr);         
}

Please note we're multiplying the PHP unix timestamp by 1000 to make it JS compatible.

Reference: http://www.w3schools.com/jsref/jsref_utc.asp

answered 2012-06-07T19:09:40.837

Highcharts data series issue with ajax/json and PHP

1 Answer

Your Answer