PHP D3 combination for visualizing data

Question

I am trying to visualize the data from the currencylayer API.
I am trying to use this as an example: http://bl.ocks.org/Caged/6476579

Here is my php code:

<?php
$response = json_decode(file_get_contents("http://apilayer.net/api/live?access_key=xxxxxxxxxxx&format=1", true));

$keys_array = array();
$values_array = array();
$arra = array();
foreach($response->quotes as $key => $value) {
//    echo "$key is at $value\n";
//      array_push($keys_array, substr($key,3));
//    array_push($values_array,$value);

    array_push($arra,{"letter":substr($key,3),"frequency":$value});
}
print_r($arra);
?>

I am trying to achieve the data in the form of:

[
  {letter: "A", frequency: .08167},
  {letter: "B", frequency: .01492},
  {letter: "C", frequency: .02780},
  {letter: "D", frequency: .04253},
  {letter: "E", frequency: .12702},
  {letter: "F", frequency: .02288},
  {letter: "G", frequency: .02022},
  {letter: "H", frequency: .06094},
  {letter: "I", frequency: .06973},
  {letter: "J", frequency: .00153},
  {letter: "K", frequency: .00747},
  {letter: "L", frequency: .04025},
  {letter: "M", frequency: .02517},
  {letter: "N", frequency: .06749},
  {letter: "O", frequency: .07507},
  {letter: "P", frequency: .01929},
  {letter: "Q", frequency: .00098},
  {letter: "R", frequency: .05987},
  {letter: "S", frequency: .06333},
  {letter: "T", frequency: .09056},
  {letter: "U", frequency: .02758},
  {letter: "V", frequency: .01037},
  {letter: "W", frequency: .02465},
  {letter: "X", frequency: .00150},
  {letter: "Y", frequency: .01971},
  {letter: "Z", frequency: .00074}
]

If I get the values in the above format then I can assign the php variable to the d3 data variable and visualize accordingly.

The above php code is giving error as follows:

Parse error: syntax error, unexpected '{' in file.php on line 18

Kindly, help me in fixing the error and assignment of the variable to the d3.

Answer 1

Your missing JSON with PHP, JSON is an javascript object anotation and it won't work in php. You need to use arrays in php and then encode them as json.

<?php
$response = json_decode(file_get_contents("http://apilayer.net/api/live?access_key=xxxxxxxxxxx&format=1", true));

$keys_array = array();
$values_array = array();
$arra = array();
foreach($response->quotes as $key => $value) {
//    echo "$key is at $value\n";
//      array_push($keys_array, substr($key,3));
//    array_push($values_array,$value);

    $arra[] = [
        "letter" => substr($key,3),
        "frequency" => $value
    ];
}
print_r($arra);

// echo json_encode($arra); // to convert the array to json 
?>

Answer 2

Just change your line from

array_push($arra,{"letter":substr($key,3),"frequency":$value});

to

array_push($arra,array("letter"=>substr($key,3),"frequency"$value));

Since i dont have the conent of that file so can't predict wether it can fix the issue.