e64729521d
- Add additional comments for reducer functions. - Add comments for CacheNode ## Bug - [ ] Related issues linked using `fixes #number` - [ ] Integration tests added - [ ] Errors have helpful link attached, see `contributing.md` ## Feature - [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR. - [ ] Related issues linked using `fixes #number` - [ ] Integration tests added - [ ] Documentation added - [ ] Telemetry added. In case of a feature if it's used or not. - [ ] Errors have helpful link attached, see `contributing.md` ## Documentation / Examples - [ ] Make sure the linting passes by running `pnpm lint` - [ ] The examples guidelines are followed from [our contributing doc](https://github.com/vercel/next.js/blob/canary/contributing.md#adding-examples)
798 lines
26 KiB
TypeScript
798 lines
26 KiB
TypeScript
import type { CacheNode } from '../../shared/lib/app-router-context'
|
|
import type {
|
|
FlightRouterState,
|
|
FlightData,
|
|
FlightDataPath,
|
|
} from '../../server/app-render'
|
|
import { matchSegment } from './match-segments'
|
|
import { fetchServerResponse } from './app-router.client'
|
|
|
|
/**
|
|
* Fill cache with subTreeData based on flightDataPath
|
|
*/
|
|
function fillCacheWithNewSubTreeData(
|
|
newCache: CacheNode,
|
|
existingCache: CacheNode,
|
|
flightDataPath: FlightDataPath
|
|
): void {
|
|
const isLastEntry = flightDataPath.length <= 4
|
|
const [parallelRouteKey, segment] = flightDataPath
|
|
|
|
const segmentForCache = Array.isArray(segment) ? segment[1] : segment
|
|
|
|
const existingChildSegmentMap =
|
|
existingCache.parallelRoutes.get(parallelRouteKey)
|
|
|
|
if (!existingChildSegmentMap) {
|
|
// Bailout because the existing cache does not have the path to the leaf node
|
|
// Will trigger lazy fetch in layout-router because of missing segment
|
|
return
|
|
}
|
|
|
|
let childSegmentMap = newCache.parallelRoutes.get(parallelRouteKey)
|
|
if (!childSegmentMap || childSegmentMap === existingChildSegmentMap) {
|
|
childSegmentMap = new Map(existingChildSegmentMap)
|
|
newCache.parallelRoutes.set(parallelRouteKey, childSegmentMap)
|
|
}
|
|
|
|
const existingChildCacheNode = existingChildSegmentMap.get(segmentForCache)
|
|
let childCacheNode = childSegmentMap.get(segmentForCache)
|
|
|
|
// In case of last segment start the fetch at this level and don't copy further down.
|
|
if (isLastEntry) {
|
|
if (
|
|
!childCacheNode ||
|
|
!childCacheNode.data ||
|
|
childCacheNode === existingChildCacheNode
|
|
) {
|
|
childSegmentMap.set(segmentForCache, {
|
|
data: null,
|
|
subTreeData: flightDataPath[3],
|
|
parallelRoutes: new Map(),
|
|
})
|
|
}
|
|
return
|
|
}
|
|
|
|
if (!childCacheNode || !existingChildCacheNode) {
|
|
// Bailout because the existing cache does not have the path to the leaf node
|
|
// Will trigger lazy fetch in layout-router because of missing segment
|
|
return
|
|
}
|
|
|
|
if (childCacheNode === existingChildCacheNode) {
|
|
childCacheNode = {
|
|
data: childCacheNode.data,
|
|
subTreeData: childCacheNode.subTreeData,
|
|
parallelRoutes: new Map(childCacheNode.parallelRoutes),
|
|
}
|
|
childSegmentMap.set(segmentForCache, childCacheNode)
|
|
}
|
|
|
|
fillCacheWithNewSubTreeData(
|
|
childCacheNode,
|
|
existingChildCacheNode,
|
|
flightDataPath.slice(2)
|
|
)
|
|
}
|
|
|
|
/**
|
|
* Kick off fetch based on the common layout between two routes. Fill cache with data property holding the in-progress fetch.
|
|
*/
|
|
function fillCacheWithDataProperty(
|
|
newCache: CacheNode,
|
|
existingCache: CacheNode,
|
|
segments: string[],
|
|
fetchResponse: any
|
|
): { bailOptimistic: boolean } | undefined {
|
|
const isLastEntry = segments.length === 1
|
|
|
|
const parallelRouteKey = 'children'
|
|
const [segment] = segments
|
|
|
|
const existingChildSegmentMap =
|
|
existingCache.parallelRoutes.get(parallelRouteKey)
|
|
|
|
if (!existingChildSegmentMap) {
|
|
// Bailout because the existing cache does not have the path to the leaf node
|
|
// Will trigger lazy fetch in layout-router because of missing segment
|
|
return { bailOptimistic: true }
|
|
}
|
|
|
|
let childSegmentMap = newCache.parallelRoutes.get(parallelRouteKey)
|
|
|
|
if (!childSegmentMap || childSegmentMap === existingChildSegmentMap) {
|
|
childSegmentMap = new Map(existingChildSegmentMap)
|
|
newCache.parallelRoutes.set(parallelRouteKey, childSegmentMap)
|
|
}
|
|
|
|
const existingChildCacheNode = existingChildSegmentMap.get(segment)
|
|
let childCacheNode = childSegmentMap.get(segment)
|
|
|
|
// In case of last segment start off the fetch at this level and don't copy further down.
|
|
if (isLastEntry) {
|
|
if (
|
|
!childCacheNode ||
|
|
!childCacheNode.data ||
|
|
childCacheNode === existingChildCacheNode
|
|
) {
|
|
childSegmentMap.set(segment, {
|
|
data: fetchResponse(),
|
|
subTreeData: null,
|
|
parallelRoutes: new Map(),
|
|
})
|
|
}
|
|
return
|
|
}
|
|
|
|
if (!childCacheNode || !existingChildCacheNode) {
|
|
// Start fetch in the place where the existing cache doesn't have the data yet.
|
|
if (!childCacheNode) {
|
|
childSegmentMap.set(segment, {
|
|
data: fetchResponse(),
|
|
subTreeData: null,
|
|
parallelRoutes: new Map(),
|
|
})
|
|
}
|
|
return
|
|
}
|
|
|
|
if (childCacheNode === existingChildCacheNode) {
|
|
childCacheNode = {
|
|
data: childCacheNode.data,
|
|
subTreeData: childCacheNode.subTreeData,
|
|
parallelRoutes: new Map(childCacheNode.parallelRoutes),
|
|
}
|
|
childSegmentMap.set(segment, childCacheNode)
|
|
}
|
|
|
|
return fillCacheWithDataProperty(
|
|
childCacheNode,
|
|
existingChildCacheNode,
|
|
segments.slice(1),
|
|
fetchResponse
|
|
)
|
|
}
|
|
|
|
/**
|
|
* Decide if the segments can be optimistically rendered, kicking off the fetch in layout-router.
|
|
* - When somewhere in the path to the segment there is a loading.js this becomes true
|
|
*/
|
|
function canOptimisticallyRender(
|
|
segments: string[],
|
|
flightRouterState: FlightRouterState
|
|
): boolean {
|
|
const segment = segments[0]
|
|
const isLastSegment = segments.length === 1
|
|
const [existingSegment, existingParallelRoutes, , , loadingMarker] =
|
|
flightRouterState
|
|
// If the segments mismatch we can't resolve deeper into the tree
|
|
const segmentMatches = matchSegment(existingSegment, segment)
|
|
|
|
// If the segment mismatches we can't assume this level has loading
|
|
if (!segmentMatches) {
|
|
return false
|
|
}
|
|
|
|
const hasLoading = loadingMarker === 'loading'
|
|
// If the tree path holds at least one loading.js it will be optimistic
|
|
if (hasLoading) {
|
|
return true
|
|
}
|
|
// Above already catches the last segment case where `hasLoading` is true, so in this case it would always be `false`.
|
|
if (isLastSegment) {
|
|
return false
|
|
}
|
|
|
|
// If the existingParallelRoutes does not have a `children` parallelRouteKey we can't resolve deeper into the tree
|
|
if (!existingParallelRoutes.children) {
|
|
return hasLoading
|
|
}
|
|
|
|
// Resolve deeper in the tree as the current level did not have a loading marker
|
|
return canOptimisticallyRender(
|
|
segments.slice(1),
|
|
existingParallelRoutes.children
|
|
)
|
|
}
|
|
|
|
/**
|
|
* Create optimistic version of router state based on the existing router state and segments.
|
|
* This is used to allow rendering layout-routers up till the point where data is missing.
|
|
*/
|
|
function createOptimisticTree(
|
|
segments: string[],
|
|
flightRouterState: FlightRouterState | null,
|
|
_isFirstSegment: boolean,
|
|
parentRefetch: boolean,
|
|
_href?: string
|
|
): FlightRouterState {
|
|
const [existingSegment, existingParallelRoutes] = flightRouterState || [
|
|
null,
|
|
{},
|
|
]
|
|
const segment = segments[0]
|
|
const isLastSegment = segments.length === 1
|
|
|
|
const segmentMatches =
|
|
existingSegment !== null && matchSegment(existingSegment, segment)
|
|
const shouldRefetchThisLevel = !flightRouterState || !segmentMatches
|
|
|
|
let parallelRoutes: FlightRouterState[1] = {}
|
|
if (existingSegment !== null && segmentMatches) {
|
|
parallelRoutes = existingParallelRoutes
|
|
}
|
|
|
|
let childTree
|
|
if (!isLastSegment) {
|
|
const childItem = createOptimisticTree(
|
|
segments.slice(1),
|
|
parallelRoutes ? parallelRoutes.children : null,
|
|
false,
|
|
parentRefetch || shouldRefetchThisLevel
|
|
)
|
|
|
|
childTree = childItem
|
|
}
|
|
|
|
const result: FlightRouterState = [
|
|
segment,
|
|
{
|
|
...parallelRoutes,
|
|
...(childTree ? { children: childTree } : {}),
|
|
},
|
|
]
|
|
|
|
if (!parentRefetch && shouldRefetchThisLevel) {
|
|
result[3] = 'refetch'
|
|
}
|
|
|
|
// TODO-APP: Revisit
|
|
// Add url into the tree
|
|
// if (isFirstSegment) {
|
|
// result[2] = href
|
|
// }
|
|
// Copy the loading flag from existing tree
|
|
if (flightRouterState && flightRouterState[4]) {
|
|
result[4] = flightRouterState[4]
|
|
}
|
|
|
|
return result
|
|
}
|
|
|
|
/**
|
|
* Apply the router state from the Flight response. Creates a new router state tree.
|
|
*/
|
|
function applyRouterStatePatchToTree(
|
|
flightSegmentPath: FlightData[0],
|
|
flightRouterState: FlightRouterState,
|
|
treePatch: FlightRouterState
|
|
): FlightRouterState {
|
|
const [segment, parallelRoutes /* , url */] = flightRouterState
|
|
|
|
// Root refresh
|
|
if (flightSegmentPath.length === 1) {
|
|
const tree: FlightRouterState = [...treePatch]
|
|
|
|
// TODO-APP: revisit
|
|
// if (url) {
|
|
// tree[2] = url
|
|
// }
|
|
return tree
|
|
}
|
|
|
|
const [currentSegment, parallelRouteKey] = flightSegmentPath
|
|
|
|
// Tree path returned from the server should always match up with the current tree in the browser
|
|
if (!matchSegment(currentSegment, segment)) {
|
|
throw new Error('SEGMENT MISMATCH')
|
|
}
|
|
|
|
const lastSegment = flightSegmentPath.length === 2
|
|
|
|
const tree: FlightRouterState = [
|
|
flightSegmentPath[0],
|
|
{
|
|
...parallelRoutes,
|
|
[parallelRouteKey]: lastSegment
|
|
? treePatch
|
|
: applyRouterStatePatchToTree(
|
|
flightSegmentPath.slice(2),
|
|
parallelRoutes[parallelRouteKey],
|
|
treePatch
|
|
),
|
|
},
|
|
]
|
|
|
|
// TODO-APP: Revisit
|
|
// if (url) {
|
|
// tree[2] = url
|
|
// }
|
|
// Copy loading flag
|
|
if (flightRouterState[4]) {
|
|
tree[4] = flightRouterState[4]
|
|
}
|
|
|
|
return tree
|
|
}
|
|
|
|
export type FocusAndScrollRef = {
|
|
/**
|
|
* If focus and scroll should be set in the layout-router's useEffect()
|
|
*/
|
|
apply: boolean
|
|
}
|
|
|
|
export const ACTION_RELOAD = 'reload'
|
|
export const ACTION_NAVIGATE = 'navigate'
|
|
export const ACTION_RESTORE = 'restore'
|
|
export const ACTION_SERVER_PATCH = 'server-patch'
|
|
|
|
/**
|
|
* Reload triggers a reload of the full page data.
|
|
* - fetches the Flight data and fills subTreeData at the root of the cache.
|
|
* - The router state is updated at the root of the state tree.
|
|
*/
|
|
interface ReloadAction {
|
|
type: typeof ACTION_RELOAD
|
|
url: URL
|
|
cache: CacheNode
|
|
mutable: {
|
|
previousTree?: FlightRouterState
|
|
patchedTree?: FlightRouterState
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Navigate triggers a navigation to the provided url. It supports a combination of `cacheType` (`hard` and `soft`) and `navigateType` (`push` and `replace`).
|
|
*
|
|
* `navigateType`:
|
|
* - `push` - pushes a new history entry in the browser history
|
|
* - `replace` - replaces the current history entry in the browser history
|
|
*
|
|
* `cacheType`:
|
|
* - `hard` - Creates a new cache in one of two ways:
|
|
* - Not optimistic
|
|
* - Default if there is no loading.js.
|
|
* - Fetch data in the reducer and suspend there.
|
|
* - Copies the previous cache nodes as far as possible and applies new subTreeData.
|
|
* - Applies the new router state.
|
|
* - optimistic
|
|
* - Enabled when somewhere in the router state path to the page there is a loading.js.
|
|
* - Similar to `soft` but kicks off the data fetch in the reducer and applies `data` in the spot that should suspend.
|
|
* - This enables showing loading states while navigating.
|
|
* - Will trigger fast path or server-patch case in layout-router.
|
|
* - `soft`
|
|
* - Reuses the existing cache.
|
|
* - Creates an optimistic router state that causes the fetch to start in layout-router when there is missing data.
|
|
* - If there is no missing data the existing cache data is rendered.
|
|
*/
|
|
interface NavigateAction {
|
|
type: typeof ACTION_NAVIGATE
|
|
url: URL
|
|
cacheType: 'soft' | 'hard'
|
|
navigateType: 'push' | 'replace'
|
|
cache: CacheNode
|
|
mutable: {
|
|
previousTree?: FlightRouterState
|
|
patchedTree?: FlightRouterState
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Restore applies the provided router state.
|
|
* - Only used for `popstate` (back/forward navigation) where a known router state has to be applied.
|
|
* - Router state is applied as-is from the history state.
|
|
* - If any data is missing it will be fetched in layout-router during rendering and trigger fast path or server-patch case.
|
|
* - If no data is missing the existing cached data is rendered.
|
|
*/
|
|
interface RestoreAction {
|
|
type: typeof ACTION_RESTORE
|
|
url: URL
|
|
tree: FlightRouterState
|
|
}
|
|
|
|
/**
|
|
* Server-patch applies the provided Flight data to the cache and router tree.
|
|
* - Only triggered in layout-router when the data can't be handled in the fast path.
|
|
* - Main case where this is triggered is when a rewrite applies and Flight data for a different path is returned from the server.
|
|
* - Creates a new cache and router state with the Flight data applied.
|
|
*/
|
|
interface ServerPatchAction {
|
|
type: typeof ACTION_SERVER_PATCH
|
|
flightData: FlightData
|
|
previousTree: FlightRouterState
|
|
cache: CacheNode
|
|
}
|
|
|
|
interface PushRef {
|
|
/**
|
|
* If the app-router should push a new history entry in app-router's useEffect()
|
|
*/
|
|
pendingPush: boolean
|
|
/**
|
|
* Multi-page navigation through location.href.
|
|
*/
|
|
mpaNavigation: boolean
|
|
}
|
|
|
|
/**
|
|
* Handles keeping the state of app-router.
|
|
*/
|
|
type AppRouterState = {
|
|
/**
|
|
* The router state, this is written into the history state in app-router using replaceState/pushState.
|
|
* - Has to be serializable as it is written into the history state.
|
|
* - Holds which segments are shown on the screen.
|
|
* - Holds where loading states (loading.js) exists.
|
|
*/
|
|
tree: FlightRouterState
|
|
/**
|
|
* The cache holds React nodes for every segment that is shown on screen as well as previously shown segments and prefetched segments.
|
|
* It also holds in-progress data requests.
|
|
*/
|
|
cache: CacheNode
|
|
/**
|
|
* Decides if the update should create a new history entry and if the navigation can't be handled by app-router.
|
|
*/
|
|
pushRef: PushRef
|
|
/**
|
|
* Decides if the update should apply scroll and focus management.
|
|
*/
|
|
focusAndScrollRef: FocusAndScrollRef
|
|
/**
|
|
* The canonical url that is pushed/replaced
|
|
*/
|
|
canonicalUrl: string
|
|
}
|
|
|
|
/**
|
|
* Reducer that handles the app-router state updates.
|
|
*/
|
|
export function reducer(
|
|
state: Readonly<AppRouterState>,
|
|
action: Readonly<
|
|
ReloadAction | NavigateAction | RestoreAction | ServerPatchAction
|
|
>
|
|
): AppRouterState {
|
|
switch (action.type) {
|
|
case ACTION_RESTORE: {
|
|
const { url, tree } = action
|
|
const href = url.pathname + url.search + url.hash
|
|
|
|
return {
|
|
// Set canonical url
|
|
canonicalUrl: href,
|
|
pushRef: state.pushRef,
|
|
focusAndScrollRef: state.focusAndScrollRef,
|
|
cache: state.cache,
|
|
// Restore provided tree
|
|
tree: tree,
|
|
}
|
|
}
|
|
case ACTION_NAVIGATE: {
|
|
const { url, cacheType, navigateType, cache, mutable } = action
|
|
const { pathname, search, hash } = url
|
|
const href = pathname + search + hash
|
|
const pendingPush = navigateType === 'push'
|
|
|
|
const segments = pathname.split('/')
|
|
// TODO-APP: figure out something better for index pages
|
|
segments.push('')
|
|
|
|
// In case of soft push data fetching happens in layout-router if a segment is missing
|
|
if (cacheType === 'soft') {
|
|
// Create optimistic tree that causes missing data to be fetched in layout-router during render.
|
|
const optimisticTree = createOptimisticTree(
|
|
segments,
|
|
state.tree,
|
|
true,
|
|
false,
|
|
href
|
|
)
|
|
|
|
return {
|
|
// Set href.
|
|
canonicalUrl: href,
|
|
// Set pendingPush. mpaNavigation is handled during rendering in layout-router for this case.
|
|
pushRef: { pendingPush, mpaNavigation: false },
|
|
// All navigation requires scroll and focus management to trigger.
|
|
focusAndScrollRef: { apply: true },
|
|
// Existing cache is used for soft navigation.
|
|
cache: state.cache,
|
|
// Optimistic tree is applied.
|
|
tree: optimisticTree,
|
|
}
|
|
}
|
|
|
|
// When doing a hard push there can be two cases: with optimistic tree and without
|
|
// The with optimistic tree case only happens when the layouts have a loading state (loading.js)
|
|
// The without optimistic tree case happens when there is no loading state, in that case we suspend in this reducer
|
|
if (cacheType === 'hard') {
|
|
// Handle concurrent rendering / strict mode case where the cache and tree were already populated.
|
|
if (
|
|
mutable.patchedTree &&
|
|
JSON.stringify(mutable.previousTree) === JSON.stringify(state.tree)
|
|
) {
|
|
return {
|
|
// Set href.
|
|
canonicalUrl: href,
|
|
// TODO-APP: verify mpaNavigation not being set is correct here.
|
|
pushRef: { pendingPush, mpaNavigation: false },
|
|
// All navigation requires scroll and focus management to trigger.
|
|
focusAndScrollRef: { apply: true },
|
|
// Apply cache.
|
|
cache: cache,
|
|
// Apply patched router state.
|
|
tree: mutable.patchedTree,
|
|
}
|
|
}
|
|
|
|
// TODO-APP: flag on the tree of which part of the tree for if there is a loading boundary
|
|
/**
|
|
* If the tree can be optimistically rendered and suspend in layout-router instead of in the reducer.
|
|
*/
|
|
const isOptimistic = canOptimisticallyRender(segments, state.tree)
|
|
|
|
// Optimistic tree case.
|
|
if (isOptimistic) {
|
|
// If the optimistic tree is deeper than the current state leave that deeper part out of the fetch
|
|
const optimisticTree = createOptimisticTree(
|
|
segments,
|
|
state.tree,
|
|
true,
|
|
false,
|
|
href
|
|
)
|
|
|
|
// Fill in the cache with blank that holds the `data` field.
|
|
// TODO-APP: segments.slice(1) strips '', we can get rid of '' altogether.
|
|
// Copy subTreeData for the root node of the cache.
|
|
cache.subTreeData = state.cache.subTreeData
|
|
// Copy existing cache nodes as far as possible and fill in `data` property with the started data fetch.
|
|
// The `data` property is used to suspend in layout-router during render if it hasn't resolved yet by the time it renders.
|
|
const res = fillCacheWithDataProperty(
|
|
cache,
|
|
state.cache,
|
|
segments.slice(1),
|
|
(): { readRoot: () => FlightData } =>
|
|
fetchServerResponse(url, optimisticTree)
|
|
)
|
|
|
|
// If optimistic fetch couldn't happen it falls back to the non-optimistic case.
|
|
if (!res?.bailOptimistic) {
|
|
mutable.previousTree = state.tree
|
|
mutable.patchedTree = optimisticTree
|
|
return {
|
|
// Set href.
|
|
canonicalUrl: href,
|
|
// Set pendingPush.
|
|
pushRef: { pendingPush, mpaNavigation: false },
|
|
// All navigation requires scroll and focus management to trigger.
|
|
focusAndScrollRef: { apply: true },
|
|
// Apply patched cache.
|
|
cache: cache,
|
|
// Apply optimistic tree.
|
|
tree: optimisticTree,
|
|
}
|
|
}
|
|
}
|
|
|
|
// Below is the not-optimistic case.
|
|
|
|
// If no in-flight fetch at the top, start it.
|
|
if (!cache.data) {
|
|
cache.data = fetchServerResponse(url, state.tree)
|
|
}
|
|
|
|
// readRoot to suspend here (in the reducer) until the fetch resolves.
|
|
const flightData = cache.data.readRoot()
|
|
|
|
// Handle case when navigating to page in `pages` from `app`
|
|
if (typeof flightData === 'string') {
|
|
return {
|
|
canonicalUrl: flightData,
|
|
// Enable mpaNavigation
|
|
pushRef: { pendingPush: true, mpaNavigation: true },
|
|
// Don't apply scroll and focus management.
|
|
focusAndScrollRef: { apply: false },
|
|
cache: state.cache,
|
|
tree: state.tree,
|
|
}
|
|
}
|
|
|
|
// Remove cache.data as it has been resolved at this point.
|
|
cache.data = null
|
|
|
|
// TODO-APP: Currently the Flight data can only have one item but in the future it can have multiple paths.
|
|
const flightDataPath = flightData[0]
|
|
|
|
// The one before last item is the router state tree patch
|
|
const [treePatch] = flightDataPath.slice(-2)
|
|
|
|
// Path without the last segment, router state, and the subTreeData
|
|
const flightSegmentPath = flightDataPath.slice(0, -3)
|
|
|
|
// Create new tree based on the flightSegmentPath and router state patch
|
|
const newTree = applyRouterStatePatchToTree(
|
|
// TODO-APP: remove ''
|
|
['', ...flightSegmentPath],
|
|
state.tree,
|
|
treePatch
|
|
)
|
|
|
|
mutable.previousTree = state.tree
|
|
mutable.patchedTree = newTree
|
|
|
|
// Copy subTreeData for the root node of the cache.
|
|
cache.subTreeData = state.cache.subTreeData
|
|
// Create a copy of the existing cache with the subTreeData applied.
|
|
fillCacheWithNewSubTreeData(cache, state.cache, flightDataPath)
|
|
|
|
return {
|
|
// Set href.
|
|
canonicalUrl: href,
|
|
// Set pendingPush.
|
|
pushRef: { pendingPush, mpaNavigation: false },
|
|
// All navigation requires scroll and focus management to trigger.
|
|
focusAndScrollRef: { apply: true },
|
|
// Apply patched cache.
|
|
cache: cache,
|
|
// Apply patched tree.
|
|
tree: newTree,
|
|
}
|
|
}
|
|
|
|
// This case should never be hit as `cacheType` is required and both cases are implemented.
|
|
// Short error to save bundle space.
|
|
throw new Error('Invalid navigate')
|
|
}
|
|
case ACTION_SERVER_PATCH: {
|
|
const { flightData, previousTree, cache } = action
|
|
// When a fetch is slow to resolve it could be that you navigated away while the request was happening or before the reducer runs.
|
|
// In that case opt-out of applying the patch given that the data could be stale.
|
|
if (JSON.stringify(previousTree) !== JSON.stringify(state.tree)) {
|
|
// TODO-APP: Handle tree mismatch
|
|
console.log('TREE MISMATCH')
|
|
// Keep everything as-is.
|
|
return state
|
|
}
|
|
|
|
// Handle case when navigating to page in `pages` from `app`
|
|
if (typeof flightData === 'string') {
|
|
return {
|
|
// Set href.
|
|
canonicalUrl: flightData,
|
|
// Enable mpaNavigation as this is a navigation that the app-router shouldn't handle.
|
|
pushRef: { pendingPush: true, mpaNavigation: true },
|
|
// Don't apply scroll and focus management.
|
|
focusAndScrollRef: { apply: false },
|
|
// Other state is kept as-is.
|
|
cache: state.cache,
|
|
tree: state.tree,
|
|
}
|
|
}
|
|
|
|
// TODO-APP: Currently the Flight data can only have one item but in the future it can have multiple paths.
|
|
const flightDataPath = flightData[0]
|
|
|
|
// Slices off the last segment (which is at -3) as it doesn't exist in the tree yet
|
|
const treePath = flightDataPath.slice(0, -3)
|
|
const [treePatch] = flightDataPath.slice(-2)
|
|
|
|
const newTree = applyRouterStatePatchToTree(
|
|
// TODO-APP: remove ''
|
|
['', ...treePath],
|
|
state.tree,
|
|
treePatch
|
|
)
|
|
|
|
// Copy subTreeData for the root node of the cache.
|
|
cache.subTreeData = state.cache.subTreeData
|
|
fillCacheWithNewSubTreeData(cache, state.cache, flightDataPath)
|
|
|
|
return {
|
|
// Keep href as it was set during navigate / restore
|
|
canonicalUrl: state.canonicalUrl,
|
|
// Keep pushRef as server-patch only causes cache/tree update.
|
|
pushRef: state.pushRef,
|
|
// Keep focusAndScrollRef as server-patch only causes cache/tree update.
|
|
focusAndScrollRef: state.focusAndScrollRef,
|
|
// Apply patched router state
|
|
tree: newTree,
|
|
// Apply patched cache
|
|
cache: cache,
|
|
}
|
|
}
|
|
case ACTION_RELOAD: {
|
|
const { url, cache, mutable } = action
|
|
const href = url.pathname + url.search + url.hash
|
|
// Reload is always a replace.
|
|
const pendingPush = false
|
|
|
|
// Handle concurrent rendering / strict mode case where the cache and tree were already populated.
|
|
if (
|
|
mutable.patchedTree &&
|
|
JSON.stringify(mutable.previousTree) === JSON.stringify(state.tree)
|
|
) {
|
|
return {
|
|
// Set href.
|
|
canonicalUrl: href,
|
|
// set pendingPush (always false in this case).
|
|
pushRef: { pendingPush, mpaNavigation: false },
|
|
// Apply focus and scroll.
|
|
// TODO-APP: might need to disable this for Fast Refresh.
|
|
focusAndScrollRef: { apply: true },
|
|
cache: cache,
|
|
tree: mutable.patchedTree,
|
|
}
|
|
}
|
|
|
|
if (!cache.data) {
|
|
// Fetch data from the root of the tree.
|
|
cache.data = fetchServerResponse(url, [
|
|
state.tree[0],
|
|
state.tree[1],
|
|
state.tree[2],
|
|
'refetch',
|
|
])
|
|
}
|
|
const flightData = cache.data.readRoot()
|
|
|
|
// Handle case when navigating to page in `pages` from `app`
|
|
if (typeof flightData === 'string') {
|
|
return {
|
|
canonicalUrl: flightData,
|
|
pushRef: { pendingPush: true, mpaNavigation: true },
|
|
focusAndScrollRef: { apply: false },
|
|
cache: state.cache,
|
|
tree: state.tree,
|
|
}
|
|
}
|
|
|
|
// Remove cache.data as it has been resolved at this point.
|
|
cache.data = null
|
|
|
|
// TODO-APP: Currently the Flight data can only have one item but in the future it can have multiple paths.
|
|
const flightDataPath = flightData[0]
|
|
|
|
// FlightDataPath with more than two items means unexpected Flight data was returned
|
|
if (flightDataPath.length !== 2) {
|
|
// TODO-APP: handle this case better
|
|
console.log('RELOAD FAILED')
|
|
return state
|
|
}
|
|
|
|
// Given the path can only have two items the items are only the router state and subTreeData for the root.
|
|
const [treePatch, subTreeData] = flightDataPath
|
|
const newTree = applyRouterStatePatchToTree(
|
|
// TODO-APP: remove ''
|
|
[''],
|
|
state.tree,
|
|
treePatch
|
|
)
|
|
|
|
mutable.previousTree = state.tree
|
|
mutable.patchedTree = newTree
|
|
|
|
// Set subTreeData for the root node of the cache.
|
|
cache.subTreeData = subTreeData
|
|
|
|
return {
|
|
// Set href, this doesn't reuse the state.canonicalUrl as because of concurrent rendering the href might change between dispatching and applying.
|
|
canonicalUrl: href,
|
|
// set pendingPush (always false in this case).
|
|
pushRef: { pendingPush, mpaNavigation: false },
|
|
// TODO-APP: might need to disable this for Fast Refresh.
|
|
focusAndScrollRef: { apply: false },
|
|
// Apply patched cache.
|
|
cache: cache,
|
|
// Apply patched router state.
|
|
tree: newTree,
|
|
}
|
|
}
|
|
// This case should never be hit as dispatch is strongly typed.
|
|
default:
|
|
throw new Error('Unknown action')
|
|
}
|
|
}
|