55 lines
2.1 KiB
JavaScript
55 lines
2.1 KiB
JavaScript
/**
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* Copyright (c) Facebook, Inc. and its affiliates.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*/
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import React, { useMemo, useContext } from 'react';
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import { ReactContextError } from '@docusaurus/theme-common/internal';
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import useRouteContext from '@docusaurus/useRouteContext';
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export function useBlogMetadata() {
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const routeContext = useRouteContext();
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const blogMetadata = routeContext?.data?.blogMetadata;
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if (!blogMetadata) {
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throw new Error("useBlogMetadata() can't be called on the current route because the blog metadata could not be found in route context");
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}
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return blogMetadata;
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}
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const Context = React.createContext(null);
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/**
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* Note: we don't use `PropBlogPostContent` as context value on purpose.
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* Metadata is currently stored inside the MDX component, but we may want to
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* change that in the future.
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*/
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function useContextValue({ content, isBlogPostPage, }) {
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return useMemo(() => ({
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metadata: content.metadata,
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frontMatter: content.frontMatter,
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assets: content.assets,
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toc: content.toc,
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isBlogPostPage,
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}), [content, isBlogPostPage]);
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}
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/**
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* This is a very thin layer around the `content` received from the MDX loader.
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* It provides metadata about the blog post to the children tree.
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*/
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export function BlogPostProvider({ children, content, isBlogPostPage = false, }) {
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const contextValue = useContextValue({ content, isBlogPostPage });
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return <Context.Provider value={contextValue}>{children}</Context.Provider>;
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}
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/**
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* Returns the data of the currently browsed blog post. Gives access to
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* front matter, metadata, TOC, etc.
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* When swizzling a low-level component (e.g. the "Edit this page" link)
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* and you need some extra metadata, you don't have to drill the props
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* all the way through the component tree: simply use this hook instead.
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*/
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export function useBlogPost() {
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const blogPost = useContext(Context);
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if (blogPost === null) {
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throw new ReactContextError('BlogPostProvider');
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}
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return blogPost;
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}
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