CBPVirtualDocument::CanUserOperateDocument: Bitrix method

      
<?php 
//  CBPVirtualDocument :: CanUserOperateDocument()
//  /dist/bitrix/modules/bizproc/classes/general/virtualdocument.php:865

    function CanUserOperateDocument($operation, $userId, $documentId, $arParameters = array())
    {
        $documentId = trim($documentId);
        if (strlen($documentId) <= 0)
            return false;

        $userId = intval($userId);

        if (array_key_exists("UserIsAdmin", $arParameters))
        {
            if ($arParameters["UserIsAdmin"] === true)
                return true;
        }
        else
        {
            $arGroups = CUser::GetUserGroup($userId);
            if (in_array(1, $arGroups))
                return true;
        }

        if (!array_key_exists("TargetUser", $arParameters) || !array_key_exists("DocumentType", $arParameters))
        {
            $dbElementList = CIBlockElement::GetList(
                array(),
                array("ID" => $documentId, "SHOW_NEW" => "Y"),
                false,
                false,
                array("ID", "IBLOCK_ID", "CREATED_BY")
            );
            $arElement = $dbElementList->Fetch();

            if (!$arElement)
                return false;

            $arParameters["TargetUser"] = $arElement["CREATED_BY"];
            $arParameters["DocumentType"] = "type_".$arElement["IBLOCK_ID"];
        }

        if (!array_key_exists("AllUserGroups", $arParameters))
        {
            if (!array_key_exists("UserGroups", $arParameters))
                $arParameters["UserGroups"] = CUser::GetUserGroup($userId);

            $arParameters["AllUserGroups"] = $arParameters["UserGroups"];
            if ($userId == $arParameters["TargetUser"])
                $arParameters["AllUserGroups"][] = "author";
        }

        if (!array_key_exists("DocumentStates", $arParameters))
        {
            $arParameters["DocumentStates"] = CBPDocument::GetDocumentStates(
                array("bizproc", "CBPVirtualDocument", $arParameters["DocumentType"]),
                array("bizproc", "CBPVirtualDocument", $documentId)
            );
        }

        if (array_key_exists("WorkflowId", $arParameters))
        {
            if (array_key_exists($arParameters["WorkflowId"], $arParameters["DocumentStates"]))
                $arParameters["DocumentStates"] = array($arParameters["WorkflowId"] => $arParameters["DocumentStates"][$arParameters["WorkflowId"]]);
            else
                return false;
        }

        $arAllowableOperations = CBPDocument::GetAllowableOperations(
            $userId,
            $arParameters["AllUserGroups"],
            $arParameters["DocumentStates"]
        );

        // $arAllowableOperations == null - workflow is not a statemachine
        // $arAllowableOperations == array() - no allowable operations
        // $arAllowableOperations == array("read", ...) - allowable operations list
        if (!is_array($arAllowableOperations))
            return in_array("author", $arParameters["AllUserGroups"]);

        $r = false;
        switch ($operation)
        {
            case 0:                // DOCUMENT_OPERATION_VIEW_WORKFLOW
                $r = in_array("read", $arAllowableOperations);
                break;
            case 1:                // DOCUMENT_OPERATION_START_WORKFLOW
                $r = in_array("create", $arAllowableOperations);
                break;
            case 4:                // DOCUMENT_OPERATION_CREATE_WORKFLOW
                $r = false;
                break;
            case 2:                // DOCUMENT_OPERATION_WRITE_DOCUMENT
                $r = in_array("create", $arAllowableOperations);
                break;
            case 3:                // DOCUMENT_OPERATION_READ_DOCUMENT
                $r = in_array("read", $arAllowableOperations);
                break;
            default:
                $r = false;
        }

        return $r;
    }