JSON and CURL problems - php

Question

world! I'm having some troubles with my API script with OLX. Can someone help me, please?
I'm making a JSON that returns this:
{
"access_token": "7b1cb35b4eca28be89174d75baf66e00d2728bf6",
"ad_list": [
{
"id": "31dasa1d23",
"operation": "insert",
"category": 1040,
"subject": "Título teste - Anúncio OLX - Marília/SP",
"body": "Imóvel com Sala, Copa, Cozinha planejada e Gabinete, 3 Dormitórios sendo 1 suíte, Lavanderia com Área de Serviço Coberta, Espaço Gourmet com Churrasqueira e Chuveirão para Ducha, Garagem para 2 Carros, Cerca Elétrica e Interfone. Confira mais sobre o imóvel: http://www.silvioimoveis.com.br/imovel-residencial-professor-antonio-da-silva-penteado-marilia-sp-venda/principal/imovel/principal/5394",
"phone": 1433333333,
"type": "s",
"price": 260000,
"zipcode": "17504000",
"params":{
"rooms": "3",
"garage_spaces": "2"
},
"images": [
"http://homologacao.silvioimoveis.com.br/fotos/imoveis_internos/5394/2175ea284f81f03.jpg",
"http://homologacao.silvioimoveis.com.br/fotos/imoveis_internos/5394/bb0ff30ac2bcbae.jpg"
]
}
]
}
And my code to create this JSON is:
$json = '{
"access_token": "'.$data['access_token'].'",
"ad_list": [
{
"id": "'.$jsonGerado[0]['id'].'",
"operation": "'.$jsonGerado[0]['operation'].'",
"category": '.$jsonGerado[0]['category'].',
"subject": "'.$jsonGerado[0]['subject'].'",
"body": "'.$jsonGerado[0]['body'].'",
"phone": '.$jsonGerado[0]['phone'].',
"type": "'.$jsonGerado[0]['type'].'",
"price": '.$jsonGerado[0]['price'].',
"zipcode": "'.$jsonGerado[0]['zipcode'].'",
"params": {
"rooms": "'.$jsonGerado[0]['params']['rooms'].'",
"garage_spaces": "'.$jsonGerado[0]['params']['garage_spaces'].'"
},
"images": [
'.$jsonGerado[0]['images']['linkFotoPrincipal'].',
'.$jsonGerado[0]['images']['linkDemaisFotos'][0].',
'.$jsonGerado[0]['images']['linkDemaisFotos'][1].',
'.$jsonGerado[0]['images']['linkDemaisFotos'][2].',
'.$jsonGerado[0]['images']['linkDemaisFotos'][3].',
'.$jsonGerado[0]['images']['linkDemaisFotos'][4].',
'.$jsonGerado[0]['images']['linkDemaisFotos'][5].',
'.$jsonGerado[0]['images']['linkDemaisFotos'][6].',
'.$jsonGerado[0]['images']['linkDemaisFotos'][7].',
'.$jsonGerado[0]['images']['linkDemaisFotos'][8].',
'.$jsonGerado[0]['images']['linkDemaisFotos'][9].'
]
}
]
}';
The CURL code is:
curl_setopt_array($curl, array(
CURLOPT_URL => "https://apps.olx.com.br/autoupload/import",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "PUT",
CURLOPT_POSTFIELDS => $json
));
And finally, the error is:
When I don't use json_encode() in $json variable, I got "NULL value found..." instead of "string value found"

Answer 1

As RiggsFolly mentioned, use json_encode on a PHP array or object rather than building the JSON yourself. Here's an example of how you might do that with the example code you provided:
$json_array = array(
"access_token" => $data['access_token'],
"ad_list" => array(
array(
"id" => $jsonGerado[0]['id'],
"operation" => $jsonGerado[0]['operation'],
"category" => $jsonGerado[0]['category'],
"subject" => $jsonGerado[0]['subject'],
"body" => $jsonGerado[0]['body'],
"phone" => $jsonGerado[0]['phone'],
"type" => $jsonGerado[0]['type'],
"price" => $jsonGerado[0]['price'],
"zipcode" => $jsonGerado[0]['zipcode'],
"params" => array(
"rooms" => $jsonGerado[0]['params']['rooms'],
"garage_spaces" => $jsonGerado[0]['params']['garage_spaces']
),
"images" => array(
$jsonGerado[0]['images']['linkFotoPrincipal'],
$jsonGerado[0]['images']['linkDemaisFotos'][0],
$jsonGerado[0]['images']['linkDemaisFotos'][1],
$jsonGerado[0]['images']['linkDemaisFotos'][2],
$jsonGerado[0]['images']['linkDemaisFotos'][3],
$jsonGerado[0]['images']['linkDemaisFotos'][4],
$jsonGerado[0]['images']['linkDemaisFotos'][5],
$jsonGerado[0]['images']['linkDemaisFotos'][6],
$jsonGerado[0]['images']['linkDemaisFotos'][7],
$jsonGerado[0]['images']['linkDemaisFotos'][8],
$jsonGerado[0]['images']['linkDemaisFotos'][9]
)
)
)
);
You can then do $json = json_encode($json_array);. I hope that helps!