for example login salesforce

salesforce.php

<?php
require_once("../require.php");
class SC_Helper_SaleForce
{
// login and return access_token, url
    public function login()
    {
      // create class Log for dev, only in dev enviroment
      // $this->log_dev = new Log_Dev_Salesforce();
      // $this->log_dev->logging_debug("","login","");
      // for get client_id check page 
      //https://ap5.salesforce.com/app/mgmt/forceconnectedapps/forceAppDetail.apexp?applicationId=06P7F000000GtPF&id=0Ci7F00000000Jh
     
      $params = "grant_type=password"
      . "&client_id=".SALEFORCE_CLIENT_ID
      . "&client_secret=".SALEFORCE_CLIENT_SECRET
      . "&username=".SALEFORCE_USERNAME
      . "&password=".SALEFORCE_PASSWORD ;

      $curl_result = $this->setup_url(SALEFORCE_LOGIN_URL,"POST", $params,null);
      $response = $curl_result["response"];
      $status = $curl_result["status_code"];
      var_dump($curl_result);
      die();
      if ( $status != 200 ) {
          $error = json_encode($curl_result);
          $this->logging_err($response);
          die("Error: check again username, passoword or url, maybe you didnt combine password with keysecret");
          return 0;
      }
      return $response;
    }

// using when the customer only provide code (no password, username) and need to get the refresh_token
    public function first_freshtoken(){
      // first you need to run browser to get code
    //  https://login.salesforce.com/services/oauth2/authorize?response_type=code&client_id=3MVG9d8..z.hDcPIPaNB1ZAck34yy_Ot5hYJIv7tVjrVYZTPBP.Yi_h6OewxSSd6pqNqWvzK2Vsy7_YpfX4KN&redirect_uri=https://login.salesforce.com/services/oauth2/success
    // then get the code and update to config file

    $curl = curl_init(SALEFORCE_LOGIN_URL);
    curl_setopt($curl, CURLOPT_HEADER, false);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);

    $json_response = curl_exec($curl);
        $params = "grant_type=authorization_code"
        . "&client_id=".SALEFORCE_CLIENT_ID
        . "&client_secret=".SALEFORCE_CLIENT_SECRET
        . "&code=".SALEFORCE_CODE
        . "&redirect_uri=".SALEFORCE_DIRECT_URI ;
        $curl_result = $this->setup_url(SALEFORCE_LOGIN_URL,"POST", $params,null);
        print_r($curl_result);
        // update instance url, accesstoken 
        return 0;
    }

    function show_records($instance_url,$access_token, $object) {
      
        $query = "SELECT Name from ".$object;
        $url = "$instance_url/services/data/v20.0/query?q=" . urlencode($query);
        $curl_result = $this->setup_url($url, "GET", null,$access_token);
        $status = $curl_result["status_code"];
        // check status code later 
        if ( $status != 201) {
            $error = json_encode($curl_result);
            var_dump($curl_result);
            return 0;
        }
        else{
            $response = $curl_result["response"];
            $total_size = $response['totalSize'];
            
            echo "$total_size record(s) returned<br/><br/>";
            foreach ((array) $response['records'] as $record) {
              echo $record['Id'] . ", " . $record['Name'] . "<br/>";
              echo json_encode($record);
              echo "<br/>";
            }
            echo "<br/>";
            print_r($curl_result);
            return $response;
        }

    }

    //create new 
    
    public function create_record($instance_url, $access_token, $object, $sql) {
        $url = "$instance_url/services/data/v20.0/sobjects/$object/";
        $content = $sql;
        $curl_result = $this->setup_url($url,"POST", $content,$access_token);

        $response = $curl_result["response"];

        $status = $curl_result["status_code"];

        if($status!=201 ){
            $error = json_encode($curl_result);
            $this->logging_err($error);
          die("Error: has an account when create new");
        }
        else{
          $id = $response["id"];
        }
        echo "New record id $id<br/><br/>";

        return $id;
    }

    // update record

    public function update_record( $instance_url, $access_token, $object, $id, $sql) {
        // enable only for dev enviroment
        // $this->log_dev->logging_debug("","update, table: ".$object,"");
        $url = "$instance_url/services/data/v20.0/sobjects/$object/$id";
        $curl_result = $this->setup_url($url,"PATCH", $sql, $access_token);
        $status = $curl_result["status_code"];
        if($status!=204){
            $error = json_encode($curl_result);
            $this->logging_err($error);
            die("Error: has nad issue when update");
        }
        echo "HTTP status $status updating account<br/><br/>";
    }

    // delete record

    public function delete_record( $instance_url, $access_token,$object,$id) {

        $url = "$instance_url/services/data/v20.0/sobjects/$object/$id";
        $curl_result = $this->setup_url($url,"DELETE", null, $access_token);
        $status = $curl_result["status_code"];
        if($status!=204){
          $error = json_encode($curl_result);
          $this->logging_err($error);
          die("Error: has nad issue when delete");
        }
        echo "HTTP status $status delete account<br/><br/>";
    }

    // base setup curl
    public function setup_url($url, $method, $sql, $access_token){
        $content = $sql;
        $curl = curl_init($url);
        curl_setopt($curl, CURLOPT_HEADER, false);
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
        // if login function, no require access_token
        if($access_token!=null){
            $content = json_encode($content);
            curl_setopt($curl, CURLOPT_HTTPHEADER,
                    array("Authorization: OAuth $access_token",
                        "Content-type: application/json"));
        }
        // define method
        if($method == "POST"){
          // print_r("post method");
            curl_setopt($curl, CURLOPT_POST, true);
        }else if ($method == "PATCH") {
          // print_r("update method");
            curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "PATCH");
        } else if($method == "DELETE"){
            curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "DELETE");
        }
        if($sql!=null){
            curl_setopt($curl, CURLOPT_POSTFIELDS, $content);
        }

        $json_response = curl_exec($curl);
        // get status of the response
        $status = curl_getinfo($curl, CURLINFO_HTTP_CODE);
        if($status==401){
            $access_token = $this->refresh_token();
              if($access_token!=null){
                  curl_setopt($curl, CURLOPT_HTTPHEADER,
                          array("Authorization: OAuth $access_token",
                              "Content-type: application/json"));
              }
              $json_response = curl_exec($curl);
        }
        curl_close($curl);
        if($json_response!=""){
            $response = json_decode($json_response, true);
        }else{
            $response　= "";
        }

        $result = array(
          "status_code" => $status,
          "response" => $response,
          "access_token" => $access_token
        );
        return $result;
    }

    // refresh token if token expried
    public function refresh_token(){
        $params = "grant_type=refresh_token"
        . "&client_id=".SALEFORCE_CLIENT_ID
        . "&client_secret=".SALEFORCE_CLIENT_SECRET
        . "&refresh_token=".SALEFORCE_REFRESH_TOKEN
        ;

        $curl = curl_init(SALEFORCE_LOGIN_URL);
        curl_setopt($curl, CURLOPT_HEADER, false);
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($curl, CURLOPT_POST, true);
        curl_setopt($curl, CURLOPT_POSTFIELDS, $params);

        $json_response = curl_exec($curl);
        // get status of the response
        $status = curl_getinfo($curl, CURLINFO_HTTP_CODE);
        curl_close($curl);
        $response = json_decode($json_response, true);
        $access_token = $response["access_token"];
        if(!$access_token){
            $error = "Has an error during refresh token";
            $this->logging_err($error);
          }
        return $access_token;
    }

    //for log error 
    // public function logging_err($msg){
    //     $fileName = "salesforce_error.txt";
    //     $fp = fopen($fileName, "a");
    //     if ( !$fp ) {
    //         die("please check a permsion");
    //     }
    //     $str_log = stream_get_contents($fp);
    //     // append date/time to message
    //     $str = "[" . date("Y/m/d h:i:s", mktime()) . "] " . $msg;
    //     // write string
    //     fwrite($fp, "\n".$str);
    //     if ($fwrite === false) {
    //          die("cannot write a logs");
    //      }
    //     fclose($fp);
    // }

}