Database string value to PHP array to be used in Javascript

Question

I need to store values into a Wordpress database and the use the value in a Google Chart.

The questions are: 1. What format do I use to store it into the database? Currently I am using WP-TYPES and adding the array as follows to a Multi Line Box:

['Month','Value 1','Value 2'],['2004',1000,400],['2005',1170,460],['2006',660,1120],['2007',1030,540]

This is what it needs to output in the Javascript for the chart.

1. Convert the String to a array in PHP (Not doing it correctly) I retrieve the data with:

$graphdata = types_render_field("graph-data", array("output" => "raw","separator"=>";"));

This gives me a string value.

Then I add it to an array: $thechartcontent[$i] = [ "name" => get_the_title(), "chartheaders" => array($graphdata), ];

1. In JavaScipt: I set the PHP Array to Java

   var chart1 = <?php echo json_encode($thechartcontent[0]); ?>;

Then I get the data from the array to a var:

 var chartheaders1 = chart1['chartheaders'];

This is where I get stuck. The value that I get is a string. It needs to show exactly this:

['Month','Value 1','Value 2'],['2004',1000,400],['2005',1170,460],['2006',660,1120],['2007',1030,540] 

for it to work.

Any help please.

Answer 1

Well, it will not be exacly like you want since it's JSON encoded in JSON format. This might be useful. Or you can convert object into array in JS.

Answer 2

I suspect that what you are outputting is an array containing a string, which is not what you want. You must split $graphdata into an array of arrays containing your data before adding it to $thechartcontent:

$graphdata = substr($graphdata, 1, strlen($graphdata) - 1); // trim the opening and closing brackets
$graphdata = explode('],[', $graphdata); // split $graphdata into an array of strings
foreach($graphdata as &$row) {
    $row = explode(',', $row); // split the row into an array
}
$thechartcontent[$i] = array(
    'name' => get_the_title(),
    'chartheaders' => $graphdata
);

When you json encode the data, you should use the JSON_NUMERIC_CHECK constant, so your numbers don't get quoted as strings:

var chart1 = <?php echo json_encode($thechartcontent[0], JSON_NUMERIC_CHECK); ?>;