Neo4j using Traverser via REST HTTP - php

Question

I'm trying to use Neo4js Traverser via the HTTP API.
If I use it via curl on the command line it works fine, but when I try to use it via curl through PHP I get an error all the time.
This is curl command:
curl -H Accept:application/json -H Content-Type:application/json -X POST -d '{"order":"depth first"}' http://localhost:7474/db/data/node/5/traverse/node
And this is my PHP Code:
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "http://localhost:7474/db/data/node/5/traverse/node");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
'Accept:application/json',
'Content-Type:application/json'
));
curl_setopt($ch, CURLOPT_POSTFIELDS, '"{"order": "depth first"}"');
$output = curl_exec($ch);
echo '<pre>';
var_dump(curl_getinfo($ch));
var_dump($output);
curl_close($ch);
This is the error I get:
HTTP ERROR 500
Problem accessing
/db/data/node/5/traverse/node. Reason:
java.lang.String cannot be cast to java.util.Map
Any Ideas?

Answer 1

Looks like you have quotes before the JSON string:
curl_setopt($ch, CURLOPT_POSTFIELDS, '"{"order": "depth first"}"');
Might want to try this:
curl_setopt($ch, CURLOPT_POSTFIELDS, '{"order": "depth first"}');
EDIT: Although better yet, I'd use json_encode with an associative array to ensure proper escaping if necessary:
$json_data = array("order" => "depth first");
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($json_data));