queryThunk

Overview

A core action instantiated during (buildThunks). queryThunk leverages createAsyncThunk to initiate the query process and is used extensively throughout the codebase both as a match case and to initiate queries. The payload for the query is built using [executeEndpoint]

Functions

Before executing the payload creator function in [executeEndpoint], queryThunk executes two functions:

getPendingMeta()

1. getPendingMeta() - adds additional metadata to the action to be used in reducers or middleware.
   1. startedTimeStamp
   2. SHOULD_AUTOBATCH

condition()

Performs conditional checks based on the provided args to decide whether the query should continue or not. (also attaches the field dispatchConditionRejected: true as confirmation that the condition was checked)

if (isUpsertQuery(queryThunkArgs)) { return true }
if (requestState?.status === "pending") { return false }
if (isForcedQuery(queryThunkArgs, state)) { return true }
if (isQueryDefinition(endpointDefinition) && endpointDefinition?.forceRefetch?.({ return true }
if (fulfilledVal) { return false }
else return true

Middleware Uses

buildSlice

The query endpoint is built almost entirely off of the extraReducers matching a queryThunk pending/fulfilled/rejected actions and updates the querySubstate plus meta data accordingly. The query slice utilises the condition and attached metadata created by a queryThunk.

buildSlice additionally matches resolved (rejected OR fulfilled) queryThunks to update providedTags.

invalidationByTags

matches against all rejected/fulfilled cases for queryThunk

Polling

matches against multiple queryThunk cases

if (
  queryThunk.pending.match(action) ||
  (queryThunk.rejected.match(action) && action.meta.condition)
) {
  updatePollingInterval(action.meta.arg, mwApi)
}
if (
  queryThunk.fulfilled.match(action) ||
  (queryThunk.rejected.match(action) && !action.meta.condition)
) {
  startNextPoll(action.meta.arg, mwApi)
}

cacheLifecycle

uses queryThunk matching to differentiate between mutation cache and query cache handling

queryLifecycle

leverages the createAsyncThunk pending/fulfilled/rejected to extend the lifecycle with query specific traits, also uses it to handle onQueryStarted

batchedActions

buildMiddleware

refetchQuery refires queryThunk with arguments for the queryThunk to determine if the query should be sent or not