Having trouble passing data to Highcharts - php

Question

I am trying to pull financial stock data of multiple companies from CSVs and display the data as separate series in a Highcharts/Highstocks line chart. I have the sources setup and I am able to pull data + convert to JSON, but I am having trouble passing the data off to Highcharts. I believe I am not using the most efficient method of preparing the data for Highcharts use, and I am hoping someone can give me direction on what I've done incorrectly. Please take a look at my code and make me aware of any inefficiencies or glaring errors you see.
PHP code:
date_default_timezone_set('America/Los_Angeles');
$stocks = array('MSFT' => 'http://ichart.finance.yahoo.com/table.csv?s=MSFT', 'AAPL' => 'http://ichart.finance.yahoo.com/table.csv?s=AAPL', 'FB' => 'http://ichart.finance.yahoo.com/table.csv?s=FB');
$stocks_data = array();
foreach ($stocks as $key=>$stock) {
$fh = fopen($stock, 'r');
$header = fgetcsv($fh);
$varname = $key . '_data';
$$varname = array();
while ($line = fgetcsv($fh)) {
${$varname}[count($$varname)] = array_combine($header, $line);
}
fclose($fh);
}
foreach($MSFT_data as $val){
$MSFT[] = strtotime($val['Date']) * 1000 . ', ' . (float)$val['Close']; //sets the date as a javascript timestamp
}
$MSFT = json_encode($MSFT);
foreach($AAPL_data as $val){
$AAPL[] = strtotime($val['Date']) * 1000 . ', ' . (float)$val['Close']; //sets the date as a javascript timestamp
}
$AAPL = json_encode($AAPL);
foreach($FB_data as $val){
$FB[] = strtotime($val['Date']) * 1000 . ', ' . (float)$val['Close']; //sets the date as a javascript timestamp
}
$FB = json_encode($FB);
JS code:
$(function () {
var seriesOptions = [],
yAxisOptions = [],
colors = Highcharts.getOptions().colors;
seriesOptions[0] = {
name: 'MSFT',
data: <? php echo $MSFT; ?>
};
seriesOptions[1] = {
name: 'AAPL',
data: <? php echo $AAPL; ?>
};
seriesOptions[2] = {
name: 'FB',
data: <? php echo $FB; ?>
};
function createChart() {
chart = new Highcharts.StockChart({
chart: {
renderTo: 'container'
},
rangeSelector: {
selected: 4
},
yAxis: {
labels: {
formatter: function () {
return (this.value > 0 ? '+' : '') + this.value + '%';
}
},
plotLines: [{
value: 0,
width: 2,
color: 'silver'
}]
},
plotOptions: {
series: {
compare: 'percent'
}
},
tooltip: {
pointFormat: '<span style="color:{series.color}">{series.name}</span>: <b>{point.y}</b> ({point.change}%)<br/>',
valueDecimals: 2
},
series: seriesOptions
});
}
});
If you have any questions or need further information, please let me know with a comment.
Thanks
BTW: I have all necessary assets included for Highcharts to work; when I replace my JS + PHP with example code from the Highcharts site, it works beautifully. So the problem clearly lies in my JS + PHP code.

Answer 1

Alright, I believe I found the problem, it lies in the way that you are storing each individual point in the array.
Instead of this (which is passing a string x,y separated by a comma):
strtotime($val['Date']) * 1000 . ', ' . (float)$val['Close'];
You are going to want to use something like this (Highcharts accepts arrays or associative arrays):
array((strtotime($val['Date']) * 1000), ((float)$val['Close']));
That will store the X and Y variables as an array instead of comma separated string for the javascript to pass as data.