PHP CRM_Core_Payment_Form::validateCreditCard方法代码示例

 /**
  * Default payment instrument validation.
  *
  * Implement the usual Luhn algorithm via a static function in the CRM_Core_Payment_Form if it's a credit card
  * Not a static function, because I need to check for payment_type.
  *
  * @param array $values
  * @param array $errors
  */
 public function validatePaymentInstrument($values, &$errors)
 {
     if ($this->_paymentProcessor['payment_type'] == 1) {
         CRM_Core_Payment_Form::validateCreditCard($values, $errors);
     }
 }

 /**
  * Function for validation
  *
  * @param array $params (ref.) an assoc array of name/value pairs
  *
  * @return mixed true or array of errors
  * @access public
  * @static
  */
 static function formRule($params, $files, $self)
 {
     $errors = array();
     $priceSetId = CRM_Utils_Array::value('price_set_id', $params);
     if ($priceSetId) {
         CRM_Price_BAO_PriceField::priceSetValidation($priceSetId, $params, $errors);
         $priceFieldIDS = array();
         foreach ($self->_priceSet['fields'] as $priceIds => $dontCare) {
             if (!empty($params['price_' . $priceIds])) {
                 if (is_array($params['price_' . $priceIds])) {
                     foreach ($params['price_' . $priceIds] as $priceFldVal => $isSet) {
                         if ($isSet) {
                             $priceFieldIDS[] = $priceFldVal;
                         }
                     }
                 } else {
                     $priceFieldIDS[] = $params['price_' . $priceIds];
                 }
             }
         }
         if (!empty($priceFieldIDS)) {
             $ids = implode(',', $priceFieldIDS);
             $count = CRM_Price_BAO_PriceSet::getMembershipCount($ids);
             foreach ($count as $id => $occurance) {
                 if ($occurance > 1) {
                     $errors['_qf_default'] = ts('Select at most one option associated with the same membership type.');
                 }
             }
             foreach ($priceFieldIDS as $priceFieldId) {
                 if ($id = CRM_Core_DAO::getFieldValue('CRM_Price_DAO_PriceFieldValue', $priceFieldId, 'membership_type_id')) {
                     $self->_memTypeSelected[$id] = $id;
                 }
             }
         }
     } elseif (!CRM_Utils_Array::value(1, $params['membership_type_id'])) {
         $errors['membership_type_id'] = ts('Please select a membership type.');
     } else {
         $self->_memTypeSelected[] = $params['membership_type_id'][1];
     }
     if (!$priceSetId) {
         $numterms = CRM_Utils_Array::value('num_terms', $params);
         if ($numterms && intval($numterms) != $numterms) {
             $errors['num_terms'] = ts('Please enter an integer for the number of terms.');
         }
     }
     // Return error if empty $self->_memTypeSelected
     if ($priceSetId && empty($errors) && empty($self->_memTypeSelected)) {
         $errors['_qf_default'] = ts('Select at least one membership option.');
     }
     if (!empty($errors) && count($self->_memTypeSelected) > 1) {
         $memberOfContacts = CRM_Member_BAO_MembershipType::getMemberOfContactByMemTypes($self->_memTypeSelected);
         $duplicateMemberOfContacts = array_count_values($memberOfContacts);
         foreach ($duplicateMemberOfContacts as $countDuplicate) {
             if ($countDuplicate > 1) {
                 $errors['_qf_default'] = ts('Please do not select more than one membership associated with the same organization.');
             }
         }
     }
     //check if contact is selected in standalone mode
     if (isset($params['contact_select_id'][1]) && !$params['contact_select_id'][1]) {
         $errors['contact[1]'] = ts('Please select a contact or create new contact');
     }
     if (!empty($errors)) {
         return $errors;
     }
     if ($priceSetId && !$self->_mode && !CRM_Utils_Array::value('record_contribution', $params)) {
         $errors['record_contribution'] = ts('Record Membership Payment is required when you using price set.');
     }
     if (!$priceSetId && $self->_mode && !CRM_Utils_Array::value('financial_type_id', $params)) {
         $errors['financial_type_id'] = ts('Please enter the financial Type.');
     }
     if (CRM_Utils_Array::value('record_contribution', $params) && !CRM_Utils_Array::value('payment_instrument_id', $params)) {
         $errors['payment_instrument_id'] = ts('Paid By is a required field.');
     }
     if (CRM_Utils_Array::value('payment_processor_id', $params)) {
         // make sure that credit card number and cvv are valid
         CRM_Core_Payment_Form::validateCreditCard($params, $errors);
     }
     $joinDate = NULL;
     if (CRM_Utils_Array::value('join_date', $params)) {
         $joinDate = CRM_Utils_Date::processDate($params['join_date']);
         foreach ($self->_memTypeSelected as $memType) {
             $startDate = NULL;
             if (CRM_Utils_Array::value('start_date', $params)) {
                 $startDate = CRM_Utils_Date::processDate($params['start_date']);
             }
             // if end date is set, ensure that start date is also set
             // and that end date is later than start date
             // If selected membership type has duration unit as 'lifetime'
             // and end date is set, then give error
             $endDate = NULL;
//.........这里部分代码省略.........

 /**
  * Default payment instrument validation.
  *
  * Implement the usual Luhn algorithm via a static function in the CRM_Core_Payment_Form if it's a credit card
  * Not a static function, because I need to check for payment_type.
  *
  * @param array $values
  * @param array $errors
  */
 public function validatePaymentInstrument($values, &$errors)
 {
     if ($this->_paymentProcessor['payment_processor_type'] == 'PayPal' && !$this->isPaypalExpress($values)) {
         CRM_Core_Payment_Form::validateCreditCard($this->_paymentProcessor['id'], $values, $errors);
         CRM_Core_Form::validateMandatoryFields($this->getMandatoryFields(), $values, $errors);
     }
 }

 /**
  * global validation rules for the form
  *
  * @param array $fields posted values of the form
  *
  * @return array list of errors to be posted back to the form
  * @static
  * @access public
  */
 static function formRule($values, $files, $self)
 {
     // If $values['_qf_Participant_next'] is Delete or
     // $values['event_id'] is empty, then return
     // instead of proceeding further.
     if (CRM_Utils_Array::value('_qf_Participant_next', $values) == 'Delete' || !$values['event_id']) {
         return TRUE;
     }
     $errorMsg = array();
     //check if contact is selected in standalone mode
     if (isset($values['contact_select_id'][1]) && !$values['contact_select_id'][1]) {
         $errorMsg['contact[1]'] = ts('Please select a contact or create new contact');
     }
     if (CRM_Utils_Array::value('payment_processor_id', $values)) {
         // make sure that credit card number and cvv are valid
         CRM_Core_Payment_Form::validateCreditCard($values, $errorMsg);
     }
     if (CRM_Utils_Array::value('record_contribution', $values)) {
         if (!CRM_Utils_Array::value('financial_type_id', $values)) {
             $errorMsg['financial_type_id'] = ts('Please enter the associated Financial Type');
         }
         if (!CRM_Utils_Array::value('payment_instrument_id', $values)) {
             $errorMsg['payment_instrument_id'] = ts('Paid By is a required field.');
         }
     }
     // validate contribution status for 'Failed'.
     if ($self->_onlinePendingContributionId && CRM_Utils_Array::value('record_contribution', $values) && CRM_Utils_Array::value('contribution_status_id', $values) == array_search('Failed', CRM_Contribute_PseudoConstant::contributionStatus(NULL, 'name'))) {
         $errorMsg['contribution_status_id'] = ts('Please select a valid payment status before updating.');
     }
     // do the amount validations.
     //skip for update mode since amount is freeze, CRM-6052
     if (!$self->_id && !CRM_Utils_Array::value('total_amount', $values) && empty($self->_values['line_items']) || $self->_id && !$self->_paymentId && isset($self->_values['line_items']) && is_array($self->_values['line_items'])) {
         if ($priceSetId = CRM_Utils_Array::value('priceSetId', $values)) {
             CRM_Price_BAO_PriceField::priceSetValidation($priceSetId, $values, $errorMsg, TRUE);
         }
     }
     return CRM_Utils_Array::crmIsEmptyArray($errorMsg) ? TRUE : $errorMsg;
 }

 /**
  * global form rule
  *
  * @param array $fields  the input form values
  * @param array $files   the uploaded files if any
  * @param array $options additional user data
  *
  * @return true if no errors, else array of errors
  * @access public
  * @static
  */
 static function formRule($fields, $files, $self)
 {
     $errors = array();
     //check that either an email or firstname+lastname is included in the form(CRM-9587)
     self::checkProfileComplete($fields, $errors, $self->_eventId);
     //To check if the user is already registered for the event(CRM-2426)
     if (!$self->_skipDupeRegistrationCheck) {
         self::checkRegistration($fields, $self);
     }
     //check for availability of registrations.
     if (!$self->_allowConfirmation && !CRM_Utils_Array::value('bypass_payment', $fields) && is_numeric($self->_availableRegistrations) && CRM_Utils_Array::value('additional_participants', $fields) >= $self->_availableRegistrations) {
         $errors['additional_participants'] = ts("There is only enough space left on this event for %1 participant(s).", array(1 => $self->_availableRegistrations));
     }
     // during confirmation don't allow to increase additional participants, CRM-4320
     if ($self->_allowConfirmation && CRM_Utils_Array::value('additional_participants', $fields) && is_array($self->_additionalParticipantIds) && $fields['additional_participants'] > count($self->_additionalParticipantIds)) {
         $errors['additional_participants'] = ts("Oops. It looks like you are trying to increase the number of additional people you are registering for. You can confirm registration for a maximum of %1 additional people.", array(1 => count($self->_additionalParticipantIds)));
     }
     //don't allow to register w/ waiting if enough spaces available.
     if (CRM_Utils_Array::value('bypass_payment', $fields)) {
         if (!is_numeric($self->_availableRegistrations) || !CRM_Utils_Array::value('priceSetId', $fields) && CRM_Utils_Array::value('additional_participants', $fields) < $self->_availableRegistrations) {
             $errors['bypass_payment'] = ts("Oops. There are enough available spaces in this event. You can not add yourself to the waiting list.");
         }
     }
     if (CRM_Utils_Array::value('additional_participants', $fields) && !CRM_Utils_Rule::positiveInteger($fields['additional_participants'])) {
         $errors['additional_participants'] = ts('Please enter a whole number for Number of additional people.');
     }
     // priceset validations
     if (CRM_Utils_Array::value('priceSetId', $fields)) {
         //format params.
         $formatted = self::formatPriceSetParams($self, $fields);
         $ppParams = array($formatted);
         $priceSetErrors = self::validatePriceSet($self, $ppParams);
         $primaryParticipantCount = self::getParticipantCount($self, $ppParams);
         //get price set fields errors in.
         $errors = array_merge($errors, CRM_Utils_Array::value(0, $priceSetErrors, array()));
         $totalParticipants = $primaryParticipantCount;
         if (CRM_Utils_Array::value('additional_participants', $fields)) {
             $totalParticipants += $fields['additional_participants'];
         }
         if (!CRM_Utils_Array::value('bypass_payment', $fields) && !$self->_allowConfirmation && is_numeric($self->_availableRegistrations) && $self->_availableRegistrations < $totalParticipants) {
             $errors['_qf_default'] = ts("Only %1 Registrations available.", array(1 => $self->_availableRegistrations));
         }
         $lineItem = array();
         CRM_Price_BAO_PriceSet::processAmount($self->_values['fee'], $fields, $lineItem);
         if ($fields['amount'] < 0) {
             $errors['_qf_default'] = ts('Event Fee(s) can not be less than zero. Please select the options accordingly');
         }
     }
     if ($self->_values['event']['is_monetary']) {
         if (empty($self->_requireApproval) && !empty($fields['amount']) && $fields['amount'] > 0 && !isset($fields['payment_processor'])) {
             $errors['payment_processor'] = ts('Please select a Payment Method');
         }
         if (is_array($self->_paymentProcessor)) {
             $payment = CRM_Core_Payment::singleton($self->_mode, $self->_paymentProcessor, $this);
             $error = $payment->checkConfig($self->_mode);
             if ($error) {
                 $errors['_qf_default'] = $error;
             }
         }
         // return if this is express mode
         if ($self->_paymentProcessor && $self->_paymentProcessor['billing_mode'] & CRM_Core_Payment::BILLING_MODE_BUTTON) {
             if (CRM_Utils_Array::value($self->_expressButtonName . '_x', $fields) || CRM_Utils_Array::value($self->_expressButtonName . '_y', $fields) || CRM_Utils_Array::value($self->_expressButtonName, $fields)) {
                 return empty($errors) ? TRUE : $errors;
             }
         }
         $isZeroAmount = $skipPaymentValidation = FALSE;
         if (CRM_Utils_Array::value('priceSetId', $fields)) {
             if (CRM_Utils_Array::value('amount', $fields) == 0) {
                 $isZeroAmount = TRUE;
             }
         } elseif (CRM_Utils_Array::value('amount', $fields) && (isset($self->_values['discount'][$fields['amount']]) && CRM_Utils_Array::value('value', $self->_values['discount'][$fields['amount']]) == 0)) {
             $isZeroAmount = TRUE;
         } elseif (CRM_Utils_Array::value('amount', $fields) && (isset($self->_values['fee'][$fields['amount']]) && CRM_Utils_Array::value('value', $self->_values['fee'][$fields['amount']]) == 0)) {
             $isZeroAmount = TRUE;
         }
         if ($isZeroAmount && !($self->_forcePayement && CRM_Utils_Array::value('additional_participants', $fields))) {
             $skipPaymentValidation = TRUE;
         }
         // also return if paylater mode or zero fees for valid members
         if (CRM_Utils_Array::value('is_pay_later', $fields) || CRM_Utils_Array::value('bypass_payment', $fields) || $skipPaymentValidation || !$self->_allowConfirmation && ($self->_requireApproval || $self->_allowWaitlist)) {
             return empty($errors) ? TRUE : $errors;
         }
         if (!empty($self->_paymentFields)) {
             CRM_Core_Form::validateMandatoryFields($self->_paymentFields, $fields, $errors);
         }
         CRM_Core_Payment_Form::validateCreditCard($fields, $errors);
     }
     foreach (CRM_Contact_BAO_Contact::$_greetingTypes as $greeting) {
         if ($greetingType = CRM_Utils_Array::value($greeting, $fields)) {
//.........这里部分代码省略.........

 function validatePaymentValues($self, $fields)
 {
     if (CRM_Utils_Array::value('bypass_payment', $self->_params[0]) || $self->_allowWaitlist || empty($self->_fields) || CRM_Utils_Array::value('amount', $self->_params[0]) > 0) {
         return TRUE;
     }
     $validatePayement = FALSE;
     if (CRM_Utils_Array::value('priceSetId', $fields)) {
         $lineItem = array();
         CRM_Price_BAO_PriceSet::processAmount($self->_values['fee'], $fields, $lineItem);
         if ($fields['amount'] > 0) {
             $validatePayement = TRUE;
             // $self->_forcePayement = true;
             // return false;
         }
     } elseif (CRM_Utils_Array::value('amount', $fields) && CRM_Utils_Array::value('value', $self->_values['fee'][$fields['amount']]) > 0) {
         $validatePayement = TRUE;
     }
     if (!$validatePayement) {
         return TRUE;
     }
     $errors = array();
     CRM_Core_Form::validateMandatoryFields($self->_fields, $fields, $errors);
     // make sure that credit card number and cvv are valid
     CRM_Core_Payment_Form::validateCreditCard($self->_params[0], $errors);
     if ($errors) {
         return FALSE;
     }
     foreach (CRM_Contact_BAO_Contact::$_greetingTypes as $greeting) {
         if ($greetingType = CRM_Utils_Array::value($greeting, $self->_params[0])) {
             $customizedValue = CRM_Core_OptionGroup::getValue($greeting, 'Customized', 'name');
             if ($customizedValue == $greetingType && empty($self->_params[0][$greeting . '_custom'])) {
                 return FALSE;
             }
         }
     }
 }

//.........这里部分代码省略.........
         $min_amount = $productDAO->min_contribution;
         if ($amount < $min_amount) {
             $errors['selectProduct'] = ts('The premium you have selected requires a minimum contribution of %1', array(1 => CRM_Utils_Money::format($min_amount)));
             CRM_Core_Session::setStatus($errors['selectProduct']);
         }
     }
     if (!empty($fields['is_recur'])) {
         if ($fields['frequency_interval'] <= 0) {
             $errors['frequency_interval'] = ts('Please enter a number for how often you want to make this recurring contribution (EXAMPLE: Every 3 months).');
         }
         if ($fields['frequency_unit'] == '0') {
             $errors['frequency_unit'] = ts('Please select a period (e.g. months, years ...) for how often you want to make this recurring contribution (EXAMPLE: Every 3 MONTHS).');
         }
     }
     if (!empty($fields['is_recur']) && CRM_Utils_Array::value('payment_processor', $fields) == 0) {
         $errors['_qf_default'] = ts('You cannot set up a recurring contribution if you are not paying online by credit card.');
     }
     if (!empty($fields['is_for_organization']) && !property_exists($self, 'organizationName')) {
         if (empty($fields['onbehalf']['organization_name'])) {
             if (!empty($fields['org_option']) && !$fields['onbehalfof_id']) {
                 $errors['organization_id'] = ts('Please select an organization or enter a new one.');
             } elseif (empty($fields['org_option'])) {
                 $errors['onbehalf']['organization_name'] = ts('Please enter the organization name.');
             }
         }
         foreach ($fields['onbehalf'] as $key => $value) {
             if (strstr($key, 'email')) {
                 $emailLocType = explode('-', $key);
             }
         }
         if (empty($fields['onbehalf']["email-{$emailLocType[1]}"])) {
             $errors['onbehalf']["email-{$emailLocType[1]}"] = ts('Organization email is required.');
         }
     }
     // validate PCP fields - if not anonymous, we need a nick name value
     if ($self->_pcpId && !empty($fields['pcp_display_in_roll']) && CRM_Utils_Array::value('pcp_is_anonymous', $fields) == 0 && CRM_Utils_Array::value('pcp_roll_nickname', $fields) == '') {
         $errors['pcp_roll_nickname'] = ts('Please enter a name to include in the Honor Roll, or select \'contribute anonymously\'.');
     }
     // return if this is express mode
     $config = CRM_Core_Config::singleton();
     if ($self->_paymentProcessor && $self->_paymentProcessor['billing_mode'] & CRM_Core_Payment::BILLING_MODE_BUTTON) {
         if (!empty($fields[$self->_expressButtonName . '_x']) || !empty($fields[$self->_expressButtonName . '_y']) || CRM_Utils_Array::value($self->_expressButtonName, $fields)) {
             return $errors;
         }
     }
     //validate the pledge fields.
     if (!empty($self->_values['pledge_block_id'])) {
         //validation for pledge payment.
         if (!empty($self->_values['pledge_id'])) {
             if (empty($fields['pledge_amount'])) {
                 $errors['pledge_amount'] = ts('At least one payment option needs to be checked.');
             }
         } elseif (!empty($fields['is_pledge'])) {
             if (CRM_Utils_Rule::positiveInteger(CRM_Utils_Array::value('pledge_installments', $fields)) == FALSE) {
                 $errors['pledge_installments'] = ts('Please enter a valid number of pledge installments.');
             } else {
                 if (CRM_Utils_Array::value('pledge_installments', $fields) == NULL) {
                     $errors['pledge_installments'] = ts('Pledge Installments is required field.');
                 } elseif (CRM_Utils_array::value('pledge_installments', $fields) == 1) {
                     $errors['pledge_installments'] = ts('Pledges consist of multiple scheduled payments. Select one-time contribution if you want to make your gift in a single payment.');
                 } elseif (CRM_Utils_array::value('pledge_installments', $fields) == 0) {
                     $errors['pledge_installments'] = ts('Pledge Installments field must be > 1.');
                 }
             }
             //validation for Pledge Frequency Interval.
             if (CRM_Utils_Rule::positiveInteger(CRM_Utils_Array::value('pledge_frequency_interval', $fields)) == FALSE) {
                 $errors['pledge_frequency_interval'] = ts('Please enter a valid Pledge Frequency Interval.');
             } else {
                 if (CRM_Utils_Array::value('pledge_frequency_interval', $fields) == NULL) {
                     $errors['pledge_frequency_interval'] = ts('Pledge Frequency Interval. is required field.');
                 } elseif (CRM_Utils_array::value('pledge_frequency_interval', $fields) == 0) {
                     $errors['pledge_frequency_interval'] = ts('Pledge frequency interval field must be > 0');
                 }
             }
         }
     }
     // also return if paylater mode
     if (CRM_Utils_Array::value('payment_processor', $fields) == 0) {
         return empty($errors) ? TRUE : $errors;
     }
     // if the user has chosen a free membership or the amount is less than zero
     // i.e. we skip calling the payment processor and hence dont need credit card
     // info
     if ((double) $amount <= 0.0) {
         return $errors;
     }
     if (!empty($self->_paymentFields)) {
         CRM_Core_Form::validateMandatoryFields($self->_paymentFields, $fields, $errors);
     }
     CRM_Core_Payment_Form::validateCreditCard($fields, $errors);
     foreach (CRM_Contact_BAO_Contact::$_greetingTypes as $greeting) {
         if ($greetingType = CRM_Utils_Array::value($greeting, $fields)) {
             $customizedValue = CRM_Core_OptionGroup::getValue($greeting, 'Customized', 'name');
             if ($customizedValue == $greetingType && empty($fielse[$greeting . '_custom'])) {
                 $errors[$greeting . '_custom'] = ts('Custom %1 is a required field if %1 is of type Customized.', array(1 => ucwords(str_replace('_', " ", $greeting))));
             }
         }
     }
     return empty($errors) ? TRUE : $errors;
 }

 /**
  * Default payment instrument validation.
  *
  * Implement the usual Luhn algorithm via a static function in the CRM_Core_Payment_Form if it's a credit card
  * Not a static function, because I need to check for payment_type.
  *
  * @param array $values
  * @param array $errors
  */
 public function validatePaymentInstrument($values, &$errors)
 {
     CRM_Core_Form::validateMandatoryFields($this->getMandatoryFields(), $values, $errors);
     if ($this->_paymentProcessor['payment_type'] == 1) {
         CRM_Core_Payment_Form::validateCreditCard($this->_paymentProcessor['id'], $values, $errors);
     }
 }

 /**
  * global form rule
  *
  * @param array $fields  the input form values
  * @param array $files   the uploaded files if any
  * @param array $options additional user data
  *
  * @return true if no errors, else array of errors
  * @access public
  * @static
  */
 static function formRule($fields, $files, $self)
 {
     $errors = array();
     CRM_Core_Form::validateMandatoryFields($self->_fields, $fields, $errors);
     // make sure that credit card number and cvv are valid
     CRM_Core_Payment_Form::validateCreditCard($fields, $errors);
     return empty($errors) ? TRUE : $errors;
 }

 /**
  * global validation rules for the form
  *
  * @param $values
  * @param $files
  * @param $self
  *
  * @internal param array $fields posted values of the form
  *
  * @return array list of errors to be posted back to the form
  * @static
  * @access public
  */
 static function formRule($values, $files, $self)
 {
     // If $values['_qf_Participant_next'] is Delete or
     // $values['event_id'] is empty, then return
     // instead of proceeding further.
     if (CRM_Utils_Array::value('_qf_Participant_next', $values) == 'Delete' || !$values['event_id']) {
         return TRUE;
     }
     $errorMsg = array();
     if (!empty($values['payment_processor_id'])) {
         // make sure that credit card number and cvv are valid
         CRM_Core_Payment_Form::validateCreditCard($values, $errorMsg);
     }
     if (!empty($values['record_contribution'])) {
         if (empty($values['financial_type_id'])) {
             $errorMsg['financial_type_id'] = ts('Please enter the associated Financial Type');
         }
         if (empty($values['payment_instrument_id'])) {
             $errorMsg['payment_instrument_id'] = ts('Paid By is a required field.');
         }
     }
     // validate contribution status for 'Failed'.
     if ($self->_onlinePendingContributionId && !empty($values['record_contribution']) && CRM_Utils_Array::value('contribution_status_id', $values) == array_search('Failed', CRM_Contribute_PseudoConstant::contributionStatus(NULL, 'name'))) {
         $errorMsg['contribution_status_id'] = ts('Please select a valid payment status before updating.');
     }
     // do the amount validations.
     //skip for update mode since amount is freeze, CRM-6052
     if (!$self->_id && empty($values['total_amount']) && empty($self->_values['line_items']) || $self->_id && !$self->_paymentId && isset($self->_values['line_items']) && is_array($self->_values['line_items'])) {
         if ($priceSetId = CRM_Utils_Array::value('priceSetId', $values)) {
             CRM_Price_BAO_PriceField::priceSetValidation($priceSetId, $values, $errorMsg, TRUE);
         }
     }
     // For single additions - show validation error if the contact has already been registered
     // for this event with the same role.
     if ($self->_single && $self->_action & CRM_Core_Action::ADD) {
         $contactId = $self->_contactId;
         $eventId = CRM_Utils_Array::value('event_id', $values);
         if (!empty($contactId) && !empty($eventId)) {
             $dupeCheck = new CRM_Event_BAO_Participant();
             $dupeCheck->contact_id = $contactId;
             $dupeCheck->event_id = $eventId;
             $dupeCheck->find(TRUE);
             if (!empty($dupeCheck->id)) {
                 $errorMsg['event_id'] = ts("This contact has already been assigned to this event.");
             }
         }
     }
     return CRM_Utils_Array::crmIsEmptyArray($errorMsg) ? TRUE : $errorMsg;
 }

 /**
  * @param $fields
  * @param $files
  * @param $self
  *
  * @return array|bool
  */
 static function formRule($fields, $files, $self)
 {
     $errors = array();
     if ($self->payment_required && empty($self->_submitValues['is_pay_later'])) {
         $payment =& CRM_Core_Payment::singleton($self->_mode, $self->_paymentProcessor, $this);
         $error = $payment->checkConfig($self->_mode);
         if ($error) {
             $errors['_qf_default'] = $error;
         }
         CRM_Core_Form::validateMandatoryFields($self->_fields, $fields, $errors);
         // make sure that credit card number and cvv are valid
         CRM_Core_Payment_Form::validateCreditCard($fields, $errors);
     }
     return empty($errors) ? TRUE : $errors;
 }