From 5be004ca645bd8ab9557410eba9fa3368326885b Mon Sep 17 00:00:00 2001
From: Flupsi <upsiflu@gmail.com>
Date: Fri, 6 Jun 2025 17:38:29 +0200
Subject: [PATCH] feat(front): cache objects and make them available across
 components #2448 #2390

---
 front/src/components/library/AlbumBase.vue | 32 ++++----
 front/src/components/library/EditForm.vue  | 10 ++-
 front/src/ui/stores/data.ts                | 86 ++++++++++++++++++++++
 3 files changed, 108 insertions(+), 20 deletions(-)
 create mode 100644 front/src/ui/stores/data.ts

diff --git a/front/src/components/library/AlbumBase.vue b/front/src/components/library/AlbumBase.vue
index 33b0f6818..7617068f5 100644
--- a/front/src/components/library/AlbumBase.vue
+++ b/front/src/components/library/AlbumBase.vue
@@ -1,5 +1,5 @@
 <script setup lang="ts">
-import type { Track, Album, Artist, Library, ArtistCredit } from '~/types'
+import type { Track, Artist, Library, ArtistCredit } from '~/types'
 
 import { momentFormat } from '~/utils/filters'
 import { computed, reactive, ref, watch } from 'vue'
@@ -7,6 +7,7 @@ import { useI18n } from 'vue-i18n'
 import { useRouter, useRoute } from 'vue-router'
 import { sum } from 'lodash-es'
 import { useStore } from '~/store'
+import { useDataStore } from '~/ui/stores/data'
 import { useQueue } from '~/composables/audio/queue'
 
 import axios from 'axios'
@@ -35,13 +36,15 @@ interface Props {
 }
 
 const store = useStore()
+const dataStore = useDataStore()
 
 const emit = defineEmits<Events>()
 const props = defineProps<Props>()
 
-const object = ref<Album | null>(null)
-const artist = ref<Artist | null>(null)
-const artistCredit = ref([] as ArtistCredit[])
+const object = computed(() => dataStore.get("album", props.id).value)
+const artistCredit = computed(() => object.value?.artist_credit ?? [])
+const artist = computed(() => dataStore.get("artist", artistCredit.value[0].artist.id))
+
 const libraries = ref([] as Library[])
 const paginateBy = ref(50)
 
@@ -75,20 +78,10 @@ const {
 const isLoading = ref(false)
 const fetchData = async () => {
   isLoading.value = true
-
-  const albumResponse = await axios.get(`albums/${props.id}/`, { params: { refresh: 'true' } })
-
-  artistCredit.value = albumResponse.data.artist_credit
-
-  // fetch the first artist of the album
-  const artistResponse = await axios.get(`artists/${albumResponse.data.artist_credit[0].artist.id}/`)
-
-  artist.value = artistResponse.data
-
-  object.value = albumResponse.data
-  if (object.value) {
+  if (!object.value)
+    return
+  else
     object.value.tracks = []
-  }
 
   fetchTracks()
   isLoading.value = false
@@ -128,7 +121,7 @@ const fetchTracks = async () => {
   }
 }
 
-watch(() => props.id, fetchData, { immediate: true })
+watch(() => [props.id, object.value], fetchData, { immediate: true })
 
 const router = useRouter()
 const route = useRoute()
@@ -154,6 +147,7 @@ const remove = async () => {
   />
   <Header
     v-if="object"
+    :key="object.title /*Re-render component when title changes after an update*/"
     :h1="object.title"
     page-heading
   >
@@ -272,7 +266,7 @@ const remove = async () => {
     </Layout>
   </Header>
 
-  <div style="flex 1;">
+  <div style="flex: 1;">
     <router-view
       v-if="object"
       :key="route.fullPath"
diff --git a/front/src/components/library/EditForm.vue b/front/src/components/library/EditForm.vue
index 2d4f40ec0..bea3f6d42 100644
--- a/front/src/components/library/EditForm.vue
+++ b/front/src/components/library/EditForm.vue
@@ -7,6 +7,7 @@ import { isEqual, clone } from 'lodash-es'
 import { useI18n } from 'vue-i18n'
 import { useStore } from '~/store'
 import { useRoute } from 'vue-router'
+import { useDataStore } from '~/ui/stores/data'
 
 import axios from 'axios'
 
@@ -34,14 +35,18 @@ const props = withDefaults(defineProps<Props>(), {
   licenses: () => []
 })
 
+// Since the object may be reactive (self-updating), we need a clone to compare changes
+const originalObject = Object.assign({}, props.object)
+
 const { t } = useI18n()
 const configs = useEditConfigs()
 const store = useStore()
+const dataStore = useDataStore()
 const route = useRoute()
 
 const config = computed(() => configs[props.objectType])
 const currentState = computed(() => config.value.fields.reduce((state: ReviewState, field) => {
-  state[field.id] = { value: field.getValue(props.object) }
+  state[field.id] = { value: field.getValue(originalObject) }
   return state
 }, {}))
 
@@ -123,6 +128,9 @@ const submit = async () => {
     })
 
     submittedMutation.value = response.data
+
+    // Immediately re-fetch the updated object into the store
+    dataStore.get(props.objectType, props.object.id!.toString(), { immediate: true })
   } catch (error) {
     errors.value = (error as BackendError).backendErrors
   }
diff --git a/front/src/ui/stores/data.ts b/front/src/ui/stores/data.ts
new file mode 100644
index 000000000..f1952714a
--- /dev/null
+++ b/front/src/ui/stores/data.ts
@@ -0,0 +1,86 @@
+import { defineStore } from 'pinia'
+import { ref, computed, type Ref } from 'vue'
+import axios from 'axios'
+
+import type { Album, Artist, Track } from '~/types'
+
+/**
+ * Fetch an item from the API.
+ * - Rate limiting: Caches the result for 1 second to prevent over-fetching and request duplication (override with { immediate: true})
+ * - Sharing reactive objects across components: Avoid data duplication, and auto-update the Ui whenever an updated version of the data is re-fetched
+ * - Strongly typed results
+ * - TODO: Errors and Loading states (`undefined` can mean an error occurred, or the request is still pending)
+ *
+ * **Example**
+ * ```ts
+ * import { useDataStore } from '~/ui/stores/data'
+ *
+ * const data = useDataStore()
+ *
+ * artist15 = data.get("artist", "15") // Ref<Artist | undefined>
+ * const album23 = data.get("album", "23") // Ref<Album | undefined>
+ * ```
+ * As soon as you re-fetch data, all references to the same object in all components using this store will be updated.
+ *
+ * Note: Pinia does not support destructuring.
+ * Do not write `{ get } = useDataStore()`
+ */
+export const useDataStore
+  = defineStore('data', () => {
+
+    // Type map that associates cache keys with their corresponding types
+    type ItemType = {
+      artist: Artist
+      album: Album
+      track: Track
+      // Add new types here (channel: Channel...)
+    }
+
+    type Items<I extends keyof ItemType> = Record<number | string, {
+      result: Ref<ItemType[I] | undefined>;
+      timestamp: number;
+    }>;
+
+    type Cache = {
+      [I in keyof ItemType]: Items<I>
+    }
+
+    const cache: Cache = {
+      artist: {},
+      album: {},
+      track: {}
+    }
+
+    /** Inspect the cache with the Vue Devtools (Pinia tab); read-only */
+    const data = computed(() => cache)
+
+    /**
+    * @param type - either 'artist' or 'album' etc.
+    * @param id - The ID of the item to fetch.
+    * @param immediate - Whether to re-fetch immediately (default: only re-fetch data older than 1 second)
+    * @returns an auto-updating reference to `undefined` if there is an error or the item is not yet loaded, or the actual item once it is loaded.
+    *
+    * Tip: Re-run after 1 second to refresh the data.
+    */
+    const get = <I extends keyof ItemType>(type: I, id: number | string, options?: { immediate?: boolean }) => {
+      // Override limited typescript inference (Remove assertion once typescript can infer correctly)
+      const items = cache[type] as Items<I>
+
+      // Initialize the object if it doesn't exist
+      if (!items[id])
+        items[id] = { result: ref(undefined) as Ref<ItemType[I] | undefined>, timestamp: 0 }
+
+      // Re-fetch if immediate is true or the item is not cached or older than 1 second
+      if (options?.immediate || items[id].timestamp < Date.now() - 1000)
+        axios.get<ItemType[I]>(`${type}s/${id}/`, { params: { refresh: 'true' } }).then(({ data }) => {
+          items[id].result.value = data;
+          items[id].timestamp = Date.now();
+        })
+      return items[id].result
+    }
+
+    return {
+      data,
+      get
+    }
+  })