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| 1 | +/** @jsxImportSource preact */ |
| 2 | + |
| 3 | +import { |
| 4 | + type ReadonlySignal, |
| 5 | + useSignal, |
| 6 | + useSignalEffect, |
| 7 | +} from "@preact/signals"; |
| 8 | +import { render } from "preact"; |
| 9 | +import type { User } from "jsonplaceholder-types/types/user"; |
| 10 | +import type { Post } from "jsonplaceholder-types/types/post"; |
| 11 | + |
| 12 | +const urlBase = "https://jsonplaceholder.typicode.com"; |
| 13 | + |
| 14 | +function useUsers() { |
| 15 | + const users = useSignal<User[] | undefined>(undefined); |
| 16 | + const loading = useSignal(false); |
| 17 | + |
| 18 | + useSignalEffect(function fetchUsers() { |
| 19 | + const ctrl = new AbortController(); |
| 20 | + const signal = ctrl.signal; |
| 21 | + |
| 22 | + loading.value = true; |
| 23 | + fetch(`${urlBase}/users`, { signal }) |
| 24 | + .then(async (response) => { |
| 25 | + const data = await response.json(); |
| 26 | + if (signal.aborted) return; |
| 27 | + users.value = data; |
| 28 | + }) |
| 29 | + .catch((error) => { |
| 30 | + if (!(error instanceof DOMException && error.name === "AbortError")) { |
| 31 | + throw error; |
| 32 | + } |
| 33 | + }) |
| 34 | + .finally(() => loading.value = false); |
| 35 | + |
| 36 | + return () => ctrl.abort(); |
| 37 | + }); |
| 38 | + |
| 39 | + return [users, { loading }] as const; |
| 40 | +} |
| 41 | + |
| 42 | +function usePosts(userId: ReadonlySignal<number | undefined>) { |
| 43 | + const posts = useSignal<Post[] | undefined>(undefined); |
| 44 | + const loading = useSignal(false); |
| 45 | + |
| 46 | + useSignalEffect(function fetchPosts() { |
| 47 | + if (userId.value === undefined) return; |
| 48 | + |
| 49 | + const ctrl = new AbortController(); |
| 50 | + const signal = ctrl.signal; |
| 51 | + loading.value = true; |
| 52 | + fetch(`${urlBase}/posts?userId=${userId.value}`, { signal }) |
| 53 | + .then(async (response) => { |
| 54 | + const data = await response.json(); |
| 55 | + if (signal.aborted) return; |
| 56 | + posts.value = data; |
| 57 | + }) |
| 58 | + .catch((error) => { |
| 59 | + if (!(error instanceof DOMException && error.name === "AbortError")) { |
| 60 | + throw error; |
| 61 | + } |
| 62 | + }) |
| 63 | + .finally(() => loading.value = false); |
| 64 | + |
| 65 | + return () => ctrl.abort(); |
| 66 | + }); |
| 67 | + |
| 68 | + return [posts, { loading }] as const; |
| 69 | +} |
| 70 | + |
| 71 | +function App() { |
| 72 | + const selectedUserId = useSignal<number | undefined>(undefined); |
| 73 | + const [users, { loading: loadingUsers }] = useUsers(); |
| 74 | + const [posts, { loading: loadingPosts }] = usePosts(selectedUserId); |
| 75 | + |
| 76 | + return ( |
| 77 | + <> |
| 78 | + <h1>Buildless Preact 10 app</h1> |
| 79 | + {users.value !== undefined && ( |
| 80 | + <label> |
| 81 | + Select User: |
| 82 | + <select |
| 83 | + onChange={(event) => |
| 84 | + selectedUserId.value = +event.currentTarget.value} |
| 85 | + > |
| 86 | + <option hidden selected></option> |
| 87 | + {users.value.map((user) => ( |
| 88 | + <option key={user.id} value={user.id}> |
| 89 | + @{user.username}: {user.name} |
| 90 | + </option> |
| 91 | + ))} |
| 92 | + </select> |
| 93 | + </label> |
| 94 | + ) || loadingUsers.value && <p>Loading Users...</p>} |
| 95 | + {posts.value !== undefined && ( |
| 96 | + <ul> |
| 97 | + {posts.value.map((post) => <li key={post.id}>{post.title}</li>)} |
| 98 | + </ul> |
| 99 | + ) || |
| 100 | + loadingPosts.value && <p>Loading Posts...</p> || |
| 101 | + users.value !== undefined && <p>Select User to view posts</p>} |
| 102 | + <p> |
| 103 | + Data Source: |
| 104 | + <a href="https://jsonplaceholder.typicode.com/" target="_blank"> |
| 105 | + JSONPlaceholder |
| 106 | + </a> |
| 107 | + </p> |
| 108 | + </> |
| 109 | + ); |
| 110 | +} |
| 111 | + |
| 112 | +render(<App />, document.body); |
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