checking for mandatory parameters in an API - php

Question

Im building an API which requires some mandatory parameters to be POSTed to it.There are about 15 mandatory parameters which should be passed to the api,I wanted to show relevant errors to the developer if there is any parameter missing like "Could not process ; email parameter is missing ".
I have already implemented the logic,but its not working well and seems to be very badly coded with excess codes.This is the current approach
if ($data['email'] AND array_key_exists('email', $data)) {
if (!validateEmail($data['email'])) {
$transaction_error = 'Invalid email';
}
} else {
$transaction_error = 'Parameter email is missing';
}
if (!($data['addr'] AND array_key_exists('addr', $data))) {
$transaction_error= 'Parameter addr is missing';
}
if (array_key_exists('show_shipping_addr', $data)) {
if (!verifyBinary($data['show_shipping_addr'])) {
$transaction_error = 'Invalid show_shipping_addr';
}
} else {
$transaction_error = 'Parameter show_shipping_addr is missing';
}
if (array_key_exists('authorize_user', $data)) {
if (!verifyBinary($data['authorize_user'])) {
$transaction_error = 'Invalid authorize_user';
}
} else {
$transaction_error = 'Parameter authorize_user is missing';
}
if ($data['mobileNo'] AND array_key_exists('mobileNo', $data)) {
if (!validateMobileNo($data['mobileNo'])) {
$transaction_error = 'Invalid mobileNo';
}
} else {
$transaction_error = 'Parameter mobileNo is missing';
}
if ($data['currency_code'] AND array_key_exists('currency_code', $data)) {
if (!validateCurrencyCode($data['currency_code'])) {
$transaction_error = 'Invalid currency_code';
}
} else {
$transaction_error = 'Parameter currency_code is missing';
}
if ($data['checksum_method'] AND array_key_exists('checksum_method', $data)) {
if (!validateChecksumMethod($data['checksum_method'])) {
$transaction_error = 'Invalid checksum_method';
}
} else {
$transaction_error = 'Parameter checksum_method is missing';
}
if ($data['zipcode'] AND array_key_exists('zipcode', $data)) {
if (!validateZipCode($data['zipcode'])) {
$transaction_error = 'Invalid zipcode';
}
} else {
$errors[$i++] = 'Parameter zipcode is missing';
}
if ($data['f_name'] AND array_key_exists('f_name', $data)) {
if (!validateAlphaString($data['f_name'])) {
$transaction_error = 'Invalid name';
}
} else {
$transaction_error = 'Parameter f_name is missing';
}
if ($data['state'] AND array_key_exists('state', $data)) {
if (!validateAlphaString($data['state'])) {
$transaction_error = 'Invalid state';
}
} else {
$transaction_error = 'Parameter state is missing';
}
if ($data['country'] AND array_key_exists('country', $data)) {
if (!validateAlphaString($data['country'])) {
$transaction_error = 'Invalid country';
}
} else {
$transaction_error = 'Parameter country is missing';
}
if ($data['city'] AND array_key_exists('city', $data)) {
if (!validateAlphaString($data['city'])) {
$transaction_error = 'Invalid city';
}
} else {
$transaction_error = 'Parameter city is missing';
}
/* Validation of mandatory parameters ends here */
/* Validation of optional parameters starts here
*shipping_email
*shipping_mobileNo
*shipping_zipcode
*l_name
*shipping_addr
*shipping_city
*shipping_state
*shipping_country
*surl
*furl
*rurl
*/
if (array_key_exists('l_name', $data)) {
if (!validateAlphaString($data['l_name'])) {
$transaction_error = 'Invalid l_name';
}
}
if (array_key_exists('shipping_addr', $data)) {
if (!$data['shipping_addr']) {
$transaction_error = 'Parameter shipping_addr is missing';
}
}
if (array_key_exists('shipping_mobileNo', $data)) {
if (!validateMobileNo($data['shipping_mobileNo'])) {
$transaction_error = 'Invalid shipping_mobileNo';
}
}
if (array_key_exists('shipping_city', $data)) {
if (!validateAlphaString($data['shipping_city'])) {
$transaction_error = 'Invalid shipping_city';
}
}
if (array_key_exists('shipping_state', $data)) {
if (!validateAlphaString($data['shipping_state'])) {
$transaction_error = 'Invalid shipping_state';
}
}
if (array_key_exists('shipping_country', $data)) {
if (!validateAlphaString($data['shipping_country'])) {
$transaction_error = 'Invalid shipping_country';
}
}
if (array_key_exists('shipping_zipcode', $data)) {
if (!validateZipCode($data['shipping_zipcode'])) {
$transaction_error = 'Invalid shipping_zipcode';
}
}
if(isset($api_error)) // IF there are API error pages are rendered
{
$api_error_array['api_error'] = $api_error;
$this->render_api_errors($api_error_array);
}
else if (isset($transaction_error)) { //If there are transactional errors,user is redirected back to mercahnt response url
$api_data = $this->paymentgateway->getAPIData($data['app_used'], $data['apikey']);
$data['response_url'] = $api_data['response_url'];
$data['transaction_errors'] = $transaction_error;
$this->paymentgateway->logApiRequest($data['app_used'], $transaction_error, 'Notice', $data['ip_address'], $data['ip_address_customer']);
$this->redirect_transactional_error($data);
} else {
$this->process($data); //Calls the process function when everything is done
}
I have got some set of mandatory fields and some set of non mandatory fields.The non mandatory fields if set need to be checked for their validity.
Please suggest a convienient way for validating post requests without making the code heavy.I have seen the following codes
if($_SERVER['REQUEST_METHOD'] != "POST")
die("Error: Wrong method");
$fields = array("f1", "f2", "f3", "f4");
$field_names = array("field1", "field2", "field3", "field4");
$length = count($fields);
$missing_input = array();
for($i = 0; $i < $length; $i++)
if(empty($_POST[$fields[$i]]))
$missing_input[] = $field_names[$i];
if(!empty($missing_input))
die("Error: " . implode(", ", $missing_input)");
from SO which makes sense.Can some suggest me a best practice of validating mandatory parameter in an API and showing relevant errors based on that?Instead of validating each paramters individually,can i make a single function whcih will check for the paramters and show the errors?

Answer 1

You can create one array of fields name which need to be mandatory / validated
$validate = array(
'username' => array('mandatory' => true, 'regex' => '/^[a-z0-9_-]{3,16}$/'),
'password' => array('mandatory' => true, 'regex' => null),
// Same like the above example you can create all validation
)
$missing_input = array();
foreach($_POST as $key => $val){
$mandatory = isset($validate[$key]) ? $validate[$key] : false;
if($mandatory && !trim($val)){
// Manage error here
$missing_input[] = $key;
}
// Same like above get the regex and validate the field here and manage the error
}
// Return / Print error array
if(!empty($missing_input))
die("Error: " . implode(", ", $missing_input)");
you can also define the min and max limit in the $validate array and inside the foreach loop validate accordingly, simple logic to validate asper your requirement.

Answer 2

$validate = array(
'username' => array('mandatory' => true, 'regex' => '/^[a-z0-9_-]{3,16}$/'),
'password' => array('mandatory' => true, 'regex' => null),
// Same like the above example you can create all validation
)
$missing_input = array();
$invalid_input = array();
foreach($_POST as $key => $val){
$mandatory = isset($validate[$key]['mandatory']) ? $validate[$key]['mandatory'] : false;
$regex = isset($validate[$key]['regex']) ? $validate[$key]['regex'] : null;
if($mandatory && !trim($val)){
// Manage error here
$missing_input[] = $key;
} else if($regex != null && trim($val)){
if(!preg_match($regex,$val)){
$invalid_input[] = $key;
}
}
}
// Return / Print error array
if(!empty($missing_input))
die("Missing Inputs: " . implode(", ", $missing_input). "Invalid Inputs" . implode(", ", $invalid_input));

Answer 3

$data = array('addr'=>'test','mobileNo'=>'test');//only for test
$dataMandatory = array('email'=>1,'addr'=>1,'mobileNo'=>1);//array of mandatory field
$transaction_error=array();//array to contain error
foreach($data as $key=>$value){
if (array_key_exists($key, $dataMandatory)) {
unset($dataMandatory[$key]);
if(!call_user_func('validate'.ucfirst($key), $value)){//i call valide method
$transaction_error[] = 'Invalid '.$key;
}
}
}
if(count($dataMandatory)!==0){
$transaction_error[] = 'Parameter missing : '.implode(',',array_flip ($dataMandatory));
}
Pros : only on array to change for add mandatory field, no duplicate code
Cons : u cant change function name (valideKey) and custom treatment