Gdn_Upload::validateUpload PHP Method

    public function validateUpload($InputName, $ThrowException = true)
    {
        $Ex = false;
        if (!array_key_exists($InputName, $_FILES) || !is_uploaded_file($_FILES[$InputName]['tmp_name']) && GetValue('error', $_FILES[$InputName], 0) == 0) {
            // Check the content length to see if we exceeded the max post size.
            $ContentLength = Gdn::request()->getValueFrom('server', 'CONTENT_LENGTH');
            $MaxPostSize = self::unformatFileSize(ini_get('post_max_size'));
            if ($ContentLength > $MaxPostSize) {
                $Ex = sprintf(t('Gdn_Upload.Error.MaxPostSize', 'The file is larger than the maximum post size. (%s)'), self::formatFileSize($MaxPostSize));
            } else {
                $Ex = t('The file failed to upload.');
            }
        } else {
            switch ($_FILES[$InputName]['error']) {
                case 1:
                case 2:
                    $MaxFileSize = self::unformatFileSize(ini_get('upload_max_filesize'));
                    $Ex = sprintf(T('Gdn_Upload.Error.PhpMaxFileSize', 'The file is larger than the server\'s maximum file size. (%s)'), self::formatFileSize($MaxFileSize));
                    break;
                case 3:
                case 4:
                    $Ex = T('The file failed to upload.');
                    break;
                case 6:
                    $Ex = T('The temporary upload folder has not been configured.');
                    break;
                case 7:
                    $Ex = T('Failed to write the file to disk.');
                    break;
                case 8:
                    $Ex = T('The upload was stopped by extension.');
                    break;
            }
        }
        $Foo = self::formatFileSize($this->_MaxFileSize);
        // Check the maxfilesize again just in case the value was spoofed in the form.
        if (!$Ex && $this->_MaxFileSize > 0 && filesize($_FILES[$InputName]['tmp_name']) > $this->_MaxFileSize) {
            $Ex = sprintf(T('Gdn_Upload.Error.MaxFileSize', 'The file is larger than the maximum file size. (%s)'), self::formatFileSize($this->_MaxFileSize));
        } elseif (!$Ex) {
            // Make sure that the file extension is allowed.
            $Extension = pathinfo($_FILES[$InputName]['name'], PATHINFO_EXTENSION);
            if (!InArrayI($Extension, $this->_AllowedFileExtensions)) {
                $Ex = sprintf(T('You cannot upload files with this extension (%s). Allowed extension(s) are %s.'), htmlspecialchars($Extension), implode(', ', $this->_AllowedFileExtensions));
            }
        }
        if ($Ex) {
            if ($ThrowException) {
                throw new Gdn_UserException($Ex);
            } else {
                $this->Exception = $Ex;
                return false;
            }
        } else {
            // If all validations were successful, return the tmp name/location of the file.
            $this->_UploadedFile = $_FILES[$InputName];
            return $this->_UploadedFile['tmp_name'];
        }
    }

 /**
  * Validates the uploaded image. Returns the temporary name of the uploaded file.
  */
 public function validateUpload($InputName, $ThrowError = true)
 {
     if (!function_exists('gd_info')) {
         throw new Exception(T('The uploaded file could not be processed because GD is not installed.'));
     }
     // Make sure that all standard file upload checks are performed.
     $TmpFileName = parent::validateUpload($InputName, $ThrowError);
     // Now perform image-specific checks.
     if ($TmpFileName) {
         $Size = getimagesize($TmpFileName);
         if ($Size === false) {
             throw new Exception(T('The uploaded file was not an image.'));
         }
     }
     return $TmpFileName;
 }