{-# LANGUAGE DeriveDataTypeable #-} {-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE OverloadedStrings #-} {-# LANGUAGE RecordWildCards #-} {-# LANGUAGE TypeFamilies #-} {-# OPTIONS_GHC -fno-warn-unused-imports #-} {-# OPTIONS_GHC -fno-warn-unused-binds #-} {-# OPTIONS_GHC -fno-warn-unused-matches #-} -- Derived from AWS service descriptions, licensed under Apache 2.0. -- | -- Module : Network.AWS.SWF.PollForDecisionTask -- Copyright : (c) 2013-2015 Brendan Hay -- License : Mozilla Public License, v. 2.0. -- Maintainer : Brendan Hay <brendan.g.hay@gmail.com> -- Stability : auto-generated -- Portability : non-portable (GHC extensions) -- -- Used by deciders to get a DecisionTask from the specified decision -- 'taskList'. A decision task may be returned for any open workflow -- execution that is using the specified task list. The task includes a -- paginated view of the history of the workflow execution. The decider -- should use the workflow type and the history to determine how to -- properly handle the task. -- -- This action initiates a long poll, where the service holds the HTTP -- connection open and responds as soon a task becomes available. If no -- decision task is available in the specified task list before the timeout -- of 60 seconds expires, an empty result is returned. An empty result, in -- this context, means that a DecisionTask is returned, but that the value -- of 'taskToken' is an empty string. -- -- Deciders should set their client-side socket timeout to at least 70 -- seconds (10 seconds higher than the timeout). -- -- Because the number of workflow history events for a single workflow -- execution might be very large, the result returned might be split up -- across a number of pages. To retrieve subsequent pages, make additional -- calls to 'PollForDecisionTask' using the 'nextPageToken' returned by the -- initial call. Note that you do __not__ call -- 'GetWorkflowExecutionHistory' with this 'nextPageToken'. Instead, call -- 'PollForDecisionTask' again. -- -- __Access Control__ -- -- You can use IAM policies to control this action\'s access to Amazon SWF -- resources as follows: -- -- - Use a 'Resource' element with the domain name to limit the action to -- only specified domains. -- - Use an 'Action' element to allow or deny permission to call this -- action. -- - Constrain the 'taskList.name' parameter by using a __Condition__ -- element with the 'swf:taskList.name' key to allow the action to -- access only certain task lists. -- -- If the caller does not have sufficient permissions to invoke the action, -- or the parameter values fall outside the specified constraints, the -- action fails. The associated event attribute\'s __cause__ parameter will -- be set to OPERATION_NOT_PERMITTED. For details and example IAM policies, -- see -- <http://docs.aws.amazon.com/amazonswf/latest/developerguide/swf-dev-iam.html Using IAM to Manage Access to Amazon SWF Workflows>. -- -- /See:/ <http://docs.aws.amazon.com/amazonswf/latest/apireference/API_PollForDecisionTask.html AWS API Reference> for PollForDecisionTask. -- -- This operation returns paginated results. module Network.AWS.SWF.PollForDecisionTask ( -- * Creating a Request pollForDecisionTask , PollForDecisionTask -- * Request Lenses , pfdtNextPageToken , pfdtReverseOrder , pfdtMaximumPageSize , pfdtIdentity , pfdtDomain , pfdtTaskList -- * Destructuring the Response , pollForDecisionTaskResponse , PollForDecisionTaskResponse -- * Response Lenses , pfdtrsNextPageToken , pfdtrsPreviousStartedEventId , pfdtrsResponseStatus , pfdtrsTaskToken , pfdtrsStartedEventId , pfdtrsWorkflowExecution , pfdtrsWorkflowType , pfdtrsEvents ) where import Network.AWS.Pager import Network.AWS.Prelude import Network.AWS.Request import Network.AWS.Response import Network.AWS.SWF.Types import Network.AWS.SWF.Types.Product -- | /See:/ 'pollForDecisionTask' smart constructor. data PollForDecisionTask = PollForDecisionTask' { _pfdtNextPageToken :: !(Maybe Text) , _pfdtReverseOrder :: !(Maybe Bool) , _pfdtMaximumPageSize :: !(Maybe Nat) , _pfdtIdentity :: !(Maybe Text) , _pfdtDomain :: !Text , _pfdtTaskList :: !TaskList } deriving (Eq,Read,Show,Data,Typeable,Generic) -- | Creates a value of 'PollForDecisionTask' with the minimum fields required to make a request. -- -- Use one of the following lenses to modify other fields as desired: -- -- * 'pfdtNextPageToken' -- -- * 'pfdtReverseOrder' -- -- * 'pfdtMaximumPageSize' -- -- * 'pfdtIdentity' -- -- * 'pfdtDomain' -- -- * 'pfdtTaskList' pollForDecisionTask :: Text -- ^ 'pfdtDomain' -> TaskList -- ^ 'pfdtTaskList' -> PollForDecisionTask pollForDecisionTask pDomain_ pTaskList_ = PollForDecisionTask' { _pfdtNextPageToken = Nothing , _pfdtReverseOrder = Nothing , _pfdtMaximumPageSize = Nothing , _pfdtIdentity = Nothing , _pfdtDomain = pDomain_ , _pfdtTaskList = pTaskList_ } -- | If a 'NextPageToken' was returned by a previous call, there are more -- results available. To retrieve the next page of results, make the call -- again using the returned token in 'nextPageToken'. Keep all other -- arguments unchanged. -- -- The configured 'maximumPageSize' determines how many results can be -- returned in a single call. -- -- The 'nextPageToken' returned by this action cannot be used with -- GetWorkflowExecutionHistory to get the next page. You must call -- PollForDecisionTask again (with the 'nextPageToken') to retrieve the -- next page of history records. Calling PollForDecisionTask with a -- 'nextPageToken' will not return a new decision task. -- -- . pfdtNextPageToken :: Lens' PollForDecisionTask (Maybe Text) pfdtNextPageToken = lens _pfdtNextPageToken (\ s a -> s{_pfdtNextPageToken = a}); -- | When set to 'true', returns the events in reverse order. By default the -- results are returned in ascending order of the 'eventTimestamp' of the -- events. pfdtReverseOrder :: Lens' PollForDecisionTask (Maybe Bool) pfdtReverseOrder = lens _pfdtReverseOrder (\ s a -> s{_pfdtReverseOrder = a}); -- | The maximum number of results that will be returned per call. -- 'nextPageToken' can be used to obtain futher pages of results. The -- default is 1000, which is the maximum allowed page size. You can, -- however, specify a page size /smaller/ than the maximum. -- -- This is an upper limit only; the actual number of results returned per -- call may be fewer than the specified maximum. pfdtMaximumPageSize :: Lens' PollForDecisionTask (Maybe Natural) pfdtMaximumPageSize = lens _pfdtMaximumPageSize (\ s a -> s{_pfdtMaximumPageSize = a}) . mapping _Nat; -- | Identity of the decider making the request, which is recorded in the -- DecisionTaskStarted event in the workflow history. This enables -- diagnostic tracing when problems arise. The form of this identity is -- user defined. pfdtIdentity :: Lens' PollForDecisionTask (Maybe Text) pfdtIdentity = lens _pfdtIdentity (\ s a -> s{_pfdtIdentity = a}); -- | The name of the domain containing the task lists to poll. pfdtDomain :: Lens' PollForDecisionTask Text pfdtDomain = lens _pfdtDomain (\ s a -> s{_pfdtDomain = a}); -- | Specifies the task list to poll for decision tasks. -- -- The specified string must not start or end with whitespace. It must not -- contain a ':' (colon), '\/' (slash), '|' (vertical bar), or any control -- characters (\\u0000-\\u001f | \\u007f - \\u009f). Also, it must not -- contain the literal string quotarnquot. pfdtTaskList :: Lens' PollForDecisionTask TaskList pfdtTaskList = lens _pfdtTaskList (\ s a -> s{_pfdtTaskList = a}); instance AWSPager PollForDecisionTask where page rq rs | stop (rs ^. pfdtrsNextPageToken) = Nothing | stop (rs ^. pfdtrsEvents) = Nothing | otherwise = Just $ rq & pfdtNextPageToken .~ rs ^. pfdtrsNextPageToken instance AWSRequest PollForDecisionTask where type Rs PollForDecisionTask = PollForDecisionTaskResponse request = postJSON sWF response = receiveJSON (\ s h x -> PollForDecisionTaskResponse' <$> (x .?> "nextPageToken") <*> (x .?> "previousStartedEventId") <*> (pure (fromEnum s)) <*> (x .:> "taskToken") <*> (x .:> "startedEventId") <*> (x .:> "workflowExecution") <*> (x .:> "workflowType") <*> (x .?> "events" .!@ mempty)) instance ToHeaders PollForDecisionTask where toHeaders = const (mconcat ["X-Amz-Target" =# ("SimpleWorkflowService.PollForDecisionTask" :: ByteString), "Content-Type" =# ("application/x-amz-json-1.0" :: ByteString)]) instance ToJSON PollForDecisionTask where toJSON PollForDecisionTask'{..} = object (catMaybes [("nextPageToken" .=) <$> _pfdtNextPageToken, ("reverseOrder" .=) <$> _pfdtReverseOrder, ("maximumPageSize" .=) <$> _pfdtMaximumPageSize, ("identity" .=) <$> _pfdtIdentity, Just ("domain" .= _pfdtDomain), Just ("taskList" .= _pfdtTaskList)]) instance ToPath PollForDecisionTask where toPath = const "/" instance ToQuery PollForDecisionTask where toQuery = const mempty -- | A structure that represents a decision task. Decision tasks are sent to -- deciders in order for them to make decisions. -- -- /See:/ 'pollForDecisionTaskResponse' smart constructor. data PollForDecisionTaskResponse = PollForDecisionTaskResponse' { _pfdtrsNextPageToken :: !(Maybe Text) , _pfdtrsPreviousStartedEventId :: !(Maybe Integer) , _pfdtrsResponseStatus :: !Int , _pfdtrsTaskToken :: !Text , _pfdtrsStartedEventId :: !Integer , _pfdtrsWorkflowExecution :: !WorkflowExecution , _pfdtrsWorkflowType :: !WorkflowType , _pfdtrsEvents :: ![HistoryEvent] } deriving (Eq,Read,Show,Data,Typeable,Generic) -- | Creates a value of 'PollForDecisionTaskResponse' with the minimum fields required to make a request. -- -- Use one of the following lenses to modify other fields as desired: -- -- * 'pfdtrsNextPageToken' -- -- * 'pfdtrsPreviousStartedEventId' -- -- * 'pfdtrsResponseStatus' -- -- * 'pfdtrsTaskToken' -- -- * 'pfdtrsStartedEventId' -- -- * 'pfdtrsWorkflowExecution' -- -- * 'pfdtrsWorkflowType' -- -- * 'pfdtrsEvents' pollForDecisionTaskResponse :: Int -- ^ 'pfdtrsResponseStatus' -> Text -- ^ 'pfdtrsTaskToken' -> Integer -- ^ 'pfdtrsStartedEventId' -> WorkflowExecution -- ^ 'pfdtrsWorkflowExecution' -> WorkflowType -- ^ 'pfdtrsWorkflowType' -> PollForDecisionTaskResponse pollForDecisionTaskResponse pResponseStatus_ pTaskToken_ pStartedEventId_ pWorkflowExecution_ pWorkflowType_ = PollForDecisionTaskResponse' { _pfdtrsNextPageToken = Nothing , _pfdtrsPreviousStartedEventId = Nothing , _pfdtrsResponseStatus = pResponseStatus_ , _pfdtrsTaskToken = pTaskToken_ , _pfdtrsStartedEventId = pStartedEventId_ , _pfdtrsWorkflowExecution = pWorkflowExecution_ , _pfdtrsWorkflowType = pWorkflowType_ , _pfdtrsEvents = mempty } -- | If a 'NextPageToken' was returned by a previous call, there are more -- results available. To retrieve the next page of results, make the call -- again using the returned token in 'nextPageToken'. Keep all other -- arguments unchanged. -- -- The configured 'maximumPageSize' determines how many results can be -- returned in a single call. pfdtrsNextPageToken :: Lens' PollForDecisionTaskResponse (Maybe Text) pfdtrsNextPageToken = lens _pfdtrsNextPageToken (\ s a -> s{_pfdtrsNextPageToken = a}); -- | The ID of the DecisionTaskStarted event of the previous decision task of -- this workflow execution that was processed by the decider. This can be -- used to determine the events in the history new since the last decision -- task received by the decider. pfdtrsPreviousStartedEventId :: Lens' PollForDecisionTaskResponse (Maybe Integer) pfdtrsPreviousStartedEventId = lens _pfdtrsPreviousStartedEventId (\ s a -> s{_pfdtrsPreviousStartedEventId = a}); -- | The response status code. pfdtrsResponseStatus :: Lens' PollForDecisionTaskResponse Int pfdtrsResponseStatus = lens _pfdtrsResponseStatus (\ s a -> s{_pfdtrsResponseStatus = a}); -- | The opaque string used as a handle on the task. This token is used by -- workers to communicate progress and response information back to the -- system about the task. pfdtrsTaskToken :: Lens' PollForDecisionTaskResponse Text pfdtrsTaskToken = lens _pfdtrsTaskToken (\ s a -> s{_pfdtrsTaskToken = a}); -- | The ID of the 'DecisionTaskStarted' event recorded in the history. pfdtrsStartedEventId :: Lens' PollForDecisionTaskResponse Integer pfdtrsStartedEventId = lens _pfdtrsStartedEventId (\ s a -> s{_pfdtrsStartedEventId = a}); -- | The workflow execution for which this decision task was created. pfdtrsWorkflowExecution :: Lens' PollForDecisionTaskResponse WorkflowExecution pfdtrsWorkflowExecution = lens _pfdtrsWorkflowExecution (\ s a -> s{_pfdtrsWorkflowExecution = a}); -- | The type of the workflow execution for which this decision task was -- created. pfdtrsWorkflowType :: Lens' PollForDecisionTaskResponse WorkflowType pfdtrsWorkflowType = lens _pfdtrsWorkflowType (\ s a -> s{_pfdtrsWorkflowType = a}); -- | A paginated list of history events of the workflow execution. The -- decider uses this during the processing of the decision task. pfdtrsEvents :: Lens' PollForDecisionTaskResponse [HistoryEvent] pfdtrsEvents = lens _pfdtrsEvents (\ s a -> s{_pfdtrsEvents = a}) . _Coerce;