php - Test third party shopping cart (Paypal) -

i trying test third party shopping cart api , empty string result.

this code trying test:

$ch = curl_init();     $params = array();     $params["cmd"]= "_cart";     $url = "https://www.sandbox.paypal.com/cgi-bin/webscr";     $params["upload"] = 1;     $params["business"] = "my business email";     $params["item_name_1"] = "item name 1";     $params["amount_1"]  = "1.00";     $params["shipping_1"] = "1.75";     $params["item_name_2"] = "item name 2";     $params["amount_2"] = "2.00";     $params["shipping_2"] ="2.50";     $params["currency_code"] = "usd";     curl_setopt($ch, curlopt_url, $url);     curl_setopt($ch, curlopt_header, false);     curl_setopt($ch, curlopt_ssl_verifypeer, false);     curl_setopt($ch, curlopt_post, true);     curl_setopt($ch, curlopt_returntransfer, true);     curl_setopt($ch, curlopt_postfields,http_build_query($params));     $response = curl_exec($ch);     $curl_errno = curl_errno($ch);     $curl_error = curl_error($ch);     curl_close($ch); 

i $response = "";

i have questions:

1. any idea doing wrong?
2. which response should get?
3. should token api (https://api.sandbox.paypal.com/v1/oauth2/token) in case secret key?

first must post paypal server not array query using http_build_query method - follow example:

$padata['l_billingagreementdescription0']   = 'product description'; $padata['l_paymentrequest_0_desc0']         = $padata['l_billingagreementdescription0'] . ' price - 0,01$'; $padata['paymentrequest_0_notifyurl']       = 'http://yourdomain.com/paypal/ipn'; $padata['paymentrequest_0_desc']            = 'product name'; //enter code here $padata['cancelurl']                        = ''http://yourdomain.com/paypal/cancelurl'; $padata['returnurl']                        = ''http://yourdomain.com/paypal/returnurl'; $padata['paymentrequest_0_currencycode']    = 'usd'; $padata['paymentrequest_0_paymentaction']   = 'sale'; $padata['paymentrequest_0_itemamt']         = $product->price; $padata['paymentrequest_0_amt']             = $product->price; $padata['l_billingtype0']                   = 'recurringpayments'; $padata['l_paymentrequest_0_name0']         = 'product name'; $padata['l_paymentrequest_0_number0']       = 223; // 'product id ' $padata['l_paymentrequest_0_qty0']          = '1'; $padata['l_paymentrequest_0_amt0']          = $product->price;  $paypal_data            = http_build_query($padata); $httpparsedresponsear   = $this->pphttppost('setexpresscheckout', $paypal_data); 

i use separated method sending data paypal api:

private function pphttppost( $methodname_, $nvpstr_ ) {      $api_username   = 'yourapiemail@paypal.com';     $api_password   = '111111';     $api_signature  = 'asddsasdaasdasdadasdfzmjezstqblyke6pi4vqhay3jwrsdopqybmhjpzasdsad.ft';     $api_endpoint   = "https://api-3t.paypal.com/nvp";     $version        = '124.0';      $ch = curl_init();     curl_setopt($ch, curlopt_url, $api_endpoint);     curl_setopt($ch, curlopt_verbose, 1);     curl_setopt($ch, curlopt_ssl_verifypeer, false);     curl_setopt($ch, curlopt_ssl_verifyhost, false);     curl_setopt($ch, curlopt_returntransfer, 1);     curl_setopt($ch, curlopt_post, 1);      $nvpreq = "method=$methodname_&version=$version&pwd=$api_password&user=$api_username&signature=$api_signature&$nvpstr_";      curl_setopt($ch, curlopt_postfields, $nvpreq);     $httpresponse = curl_exec($ch);      if(!$httpresponse) {         exit("$methodname_ failed: ".curl_error($ch).'('.curl_errno($ch).')');     }      // extract response details.     $httpresponsear = explode("&", $httpresponse);      $httpparsedresponsear = array();     foreach ($httpresponsear $i => $value) {         $tmpar = explode("=", $value);         if(sizeof($tmpar) > 1) {             $httpparsedresponsear[$tmpar[0]] = $tmpar[1];         }     }      if((0 == sizeof($httpparsedresponsear)) || !array_key_exists('ack', $httpparsedresponsear)) {         exit("invalid http response post request($nvpreq) $api_endpoint.");     }      return $httpparsedresponsear; }