POST Request using CURL and PHP not working properly - php

Question

I am trying to programmatically process my statement using the form at http://nlp.stanford.edu:8080/corenlp/process. I have the following code snippet in PHP/CURL. However, instead of processing the statement, it is returning the HTML for the form - as if the post parameters are not being sent. I checked that I am sending the required paramaters. Can someone guide me as to what I am doing wrong?
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "http://nlp.stanford.edu:8080/corenlp/process");
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);
curl_setopt($ch, CURLOPT_USERAGENT,"Mozilla/14.0 (compatible; MSIE 6.0; Windows NT 5.1)");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch, CURLOPT_POST, true);
$data = array(
'outputFormat' => 'xml',
'input' => 'Here is a statement to process',
'Process' => 'Submit Query'
);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
$result = curl_exec($ch);
echo $result;

Answer 1

You have to convert the $data array into a string... Also, Be sure to urlencode() the individual values.
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "http://nlp.stanford.edu:8080/corenlp/process");
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);
curl_setopt($ch, CURLOPT_USERAGENT,"Mozilla/14.0 (compatible; MSIE 6.0; Windows NT 5.1)");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch, CURLOPT_POST, true);
$data = array(
"outputFormat" => "xml",
"input" => "Here is a statement to process",
"Process" => "Submit Query"
);
$data_string = "";
foreach($data as $key=>$value){ /// YOU HAVE TO DO THIS
$data_string .= $key.'='.urlencode($value).'&'; /// AND THIS
}
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CURLOPT_POSTFIELDS, $data_string);
$result = curl_exec($ch);
echo $result;