library/core/class.form.php
public function ValidateRule($FieldName, $Rule, $CustomError = '') {
      $Value = $this->GetFormValue($FieldName);
      $Valid = Gdn_Validation::ValidateRule($Value, $FieldName, $Rule, $CustomError);

      if ($Valid === TRUE)
         return TRUE;
      else {
         $this->AddError('@'.$Valid);
         return FALSE;
      }
      
   }
public function ValidateRule($FieldName, $Rule, $CustomError = '') {
      $Value = $this->GetFormValue($FieldName);
      $Valid = Gdn_Validation::ValidateRule($Value, $FieldName, $Rule, $CustomError);

      if ($Valid === TRUE)
         return TRUE;
      else {
         $this->AddError('@'.$Valid);
         return FALSE;
      }
      
   }
public function ValidateRule ( $ FieldName , $ Rule , $ CustomError = '' ) { $ Value = $ this -> GetFormValue ( $ FieldName ) ; $ Valid = Gdn_Validation :: ValidateRule ( $ Value , $ FieldName , $ Rule , $ CustomError ) ; if ( $ Valid === TRUE ) return TRUE ; else { $ this -> AddError ( '@' . $ Valid ) ; return FALSE ; } }
Validates a rule on the form and adds its result to the errors collection.

@param string $FieldName The name of the field to validate.
@param string|array $Rule The rule to validate against.
@param string $CustomError A custom error string.
@return bool Whether or not the rule succeeded.

@see Gdn_Validation::ValidateRule()
Validates a rule on the form and adds its result to the errors collection .