/** * The functions provided by this module are used to communicate certain properties * about the currently running code so that Next.js can make decisions on how to handle * the current execution in different rendering modes such as pre-rendering, resuming, and SSR. * * Today Next.js treats all code as potentially static. Certain APIs may only make sense when dynamically rendering. * Traditionally this meant deopting the entire render to dynamic however with PPR we can now deopt parts * of a React tree as dynamic while still keeping other parts static. There are really two different kinds of * Dynamic indications. * * The first is simply an intention to be dynamic. unstable_noStore is an example of this where * the currently executing code simply declares that the current scope is dynamic but if you use it * inside unstable_cache it can still be cached. This type of indication can be removed if we ever * make the default dynamic to begin with because the only way you would ever be static is inside * a cache scope which this indication does not affect. * * The second is an indication that a dynamic data source was read. This is a stronger form of dynamic * because it means that it is inappropriate to cache this at all. using a dynamic data source inside * unstable_cache should error. If you want to use some dynamic data inside unstable_cache you should * read that data outside the cache and pass it in as an argument to the cached function. */ // Once postpone is in stable we should switch to importing the postpone export directly import React from "react"; import { DynamicServerError } from "../../client/components/hooks-server-context"; import { StaticGenBailoutError } from "../../client/components/static-generation-bailout"; import { getPathname } from "../../lib/url"; const hasPostpone = typeof React.unstable_postpone === "function"; export function createPrerenderState(isDebugSkeleton) { return { isDebugSkeleton, dynamicAccesses: [] }; } /** * This function communicates that the current scope should be treated as dynamic. * * In most cases this function is a no-op but if called during * a PPR prerender it will postpone the current sub-tree. */ export function markCurrentScopeAsDynamic(store, expression) { const pathname = getPathname(store.urlPathname); if (store.isUnstableCacheCallback) { // inside cache scopes marking a scope as dynamic has no effect because the outer cache scope // creates a cache boundary. This is subtly different from reading a dynamic data source which is // forbidden inside a cache scope. return; } else if (store.dynamicShouldError) { throw new StaticGenBailoutError(`Route ${pathname} with \`dynamic = "error"\` couldn't be rendered statically because it used \`${expression}\`. See more info here: https://nextjs.org/docs/app/building-your-application/rendering/static-and-dynamic#dynamic-rendering`); } else if (// We are in a prerender (PPR enabled, during build) store.prerenderState) { // We track that we had a dynamic scope that postponed. // This will be used by the renderer to decide whether // the prerender requires a resume postponeWithTracking(store.prerenderState, expression, pathname); } else { store.revalidate = 0; if (store.isStaticGeneration) { // We aren't prerendering but we are generating a static page. We need to bail out of static generation const err = new DynamicServerError(`Route ${pathname} couldn't be rendered statically because it used ${expression}. See more info here: https://nextjs.org/docs/messages/dynamic-server-error`); store.dynamicUsageDescription = expression; store.dynamicUsageStack = err.stack; throw err; } } } /** * This function communicates that some dynamic data was read. This typically would refer to accessing * a Request specific data store such as cookies or headers. This function is not how end-users will * describe reading from dynamic data sources which are valid to cache and up to the author to make * a determination of when to do so. * * If we are inside a cache scope we error * Also during a PPR Prerender we postpone */ export function trackDynamicDataAccessed(store, expression) { const pathname = getPathname(store.urlPathname); if (store.isUnstableCacheCallback) { throw new Error(`Route ${pathname} used "${expression}" inside a function cached with "unstable_cache(...)". Accessing Dynamic data sources inside a cache scope is not supported. If you need this data inside a cached function use "${expression}" outside of the cached function and pass the required dynamic data in as an argument. See more info here: https://nextjs.org/docs/app/api-reference/functions/unstable_cache`); } else if (store.dynamicShouldError) { throw new StaticGenBailoutError(`Route ${pathname} with \`dynamic = "error"\` couldn't be rendered statically because it used \`${expression}\`. See more info here: https://nextjs.org/docs/app/building-your-application/rendering/static-and-dynamic#dynamic-rendering`); } else if (// We are in a prerender (PPR enabled, during build) store.prerenderState) { // We track that we had a dynamic scope that postponed. // This will be used by the renderer to decide whether // the prerender requires a resume postponeWithTracking(store.prerenderState, expression, pathname); } else { store.revalidate = 0; if (store.isStaticGeneration) { // We aren't prerendering but we are generating a static page. We need to bail out of static generation const err = new DynamicServerError(`Route ${pathname} couldn't be rendered statically because it used \`${expression}\`. See more info here: https://nextjs.org/docs/messages/dynamic-server-error`); store.dynamicUsageDescription = expression; store.dynamicUsageStack = err.stack; throw err; } } } export function Postpone({ reason, prerenderState, pathname }) { postponeWithTracking(prerenderState, reason, pathname); } // @TODO refactor patch-fetch and this function to better model dynamic semantics. Currently this implementation // is too explicit about postponing if we are in a prerender and patch-fetch contains a lot of logic for determining // what makes the fetch "dynamic". It also doesn't handle Non PPR cases so it is isn't as consistent with the other // dynamic-rendering methods. export function trackDynamicFetch(store, expression) { if (store.prerenderState) { postponeWithTracking(store.prerenderState, expression, store.urlPathname); } } function postponeWithTracking(prerenderState, expression, pathname) { assertPostpone(); const reason = `Route ${pathname} needs to bail out of prerendering at this point because it used ${expression}. ` + `React throws this special object to indicate where. It should not be caught by ` + `your own try/catch. Learn more: https://nextjs.org/docs/messages/ppr-caught-error`; prerenderState.dynamicAccesses.push({ // When we aren't debugging, we don't need to create another error for the // stack trace. stack: prerenderState.isDebugSkeleton ? new Error().stack : undefined, expression }); React.unstable_postpone(reason); } export function usedDynamicAPIs(prerenderState) { return prerenderState.dynamicAccesses.length > 0; } export function formatDynamicAPIAccesses(prerenderState) { return prerenderState.dynamicAccesses.filter((access)=>typeof access.stack === "string" && access.stack.length > 0).map(({ expression, stack })=>{ stack = stack.split("\n")// Remove the "Error: " prefix from the first line of the stack trace as // well as the first 4 lines of the stack trace which is the distance // from the user code and the `new Error().stack` call. .slice(4).filter((line)=>{ // Exclude Next.js internals from the stack trace. if (line.includes("node_modules/next/")) { return false; } // Exclude anonymous functions from the stack trace. if (line.includes(" ()")) { return false; } // Exclude Node.js internals from the stack trace. if (line.includes(" (node:")) { return false; } return true; }).join("\n"); return `Dynamic API Usage Debug - ${expression}:\n${stack}`; }); } function assertPostpone() { if (!hasPostpone) { throw new Error(`Invariant: React.unstable_postpone is not defined. This suggests the wrong version of React was loaded. This is a bug in Next.js`); } } /** * This is a bit of a hack to allow us to abort a render using a Postpone instance instead of an Error which changes React's * abort semantics slightly. */ export function createPostponedAbortSignal(reason) { assertPostpone(); const controller = new AbortController(); // We get our hands on a postpone instance by calling postpone and catching the throw try { React.unstable_postpone(reason); } catch (x) { controller.abort(x); } return controller.signal; } //# sourceMappingURL=dynamic-rendering.js.map