feat(useObjectUrl): new function

packages/components/index.ts

@@ -32,6 +32,7 @@ export * from '../core/useMouseInElement/component'
 export * from '../core/useMousePressed/component'
 export * from '../core/useNetwork/component'
 export * from '../core/useNow/component'
+export * from '../core/useObjectUrl/component'
 export * from '../core/useOffsetPagination/component'
 export * from '../core/useOnline/component'
 export * from '../core/usePageLeave/component'

packages/core/index.ts

@@ -72,6 +72,7 @@ export * from './useMutationObserver'
 export * from './useNavigatorLanguage'
 export * from './useNetwork'
 export * from './useNow'
+export * from './useObjectUrl'
 export * from './useOffsetPagination'
 export * from './useOnline'
 export * from './usePageLeave'

packages/core/useObjectUrl/component.ts

@@ -0,0 +1,22 @@
+import { defineComponent, toRef } from 'vue-demi'
+import { useObjectUrl } from '@vueuse/core'
+
+export interface UseObjectUrlProps {
+  object: Blob | MediaSource | undefined
+}
+
+export const UseObjectUrl = defineComponent<UseObjectUrlProps>({
+  name: 'UseObjectUrl',
+  props: [
+    'object',
+  ] as unknown as undefined,
+  setup(props, { slots }) {
+    const object = toRef(props, 'object')
+    const url = useObjectUrl(object)
+
+    return () => {
+      if (slots.default && url.value)
+        return slots.default(url)
+    }
+  },
+})

packages/core/useObjectUrl/demo.vue

@@ -0,0 +1,30 @@
+<script setup lang="ts">
+import { shallowRef } from 'vue-demi'
+import { useObjectUrl } from '@vueuse/core'
+
+const file = shallowRef()
+const url = useObjectUrl(file)
+
+const onFileChange = (e: Event) => {
+  const target = e.target as HTMLInputElement
+  const files = target.files
+  file.value = files && files.length > 0 ? files[0] : undefined
+}
+</script>
+
+<template>
+  <div>
+    <note class="mb-1">
+      Select file:
+    </note>
+    <input type="file" @change="onFileChange">
+
+    <note class="mt-4 mb-1">
+      Object URL:
+    </note>
+    <code>
+      <a v-if="url" :href="url" target="_blank">{{ url }}</a>
+      <span v-else>none</span>
+    </code>
+  </div>
+</template>

packages/core/useObjectUrl/index.md

@@ -0,0 +1,41 @@
+---
+category: Browser
+---
+
+# useObjectUrl
+
+Reactive URL representing an object.
+
+Creates an URL for the provided `File`, `Blob`, or `MediaSource` via [URL.createObjectURL()](https://developer.mozilla.org/en-US/docs/Web/API/URL/createObjectURL) and automatically releases the URL via [URL.revokeObjectURL()](https://developer.mozilla.org/en-US/docs/Web/API/URL/revokeObjectURL) when the source changes or the component is unmounted.
+
+## Usage
+
+```html
+<script setup>
+import { useObjectUrl } from '@vueuse/core'
+import { shallowRef } from 'vue'
+
+const file = shallowRef()
+const url = useObjectUrl(file)
+
+const onFileChange = (e) => {
+  file.value = event.target.files[0]
+}
+</script>
+
+<template>
+  <input type="file" @change="onFileChange" />
+
+  <a :href="url">Open file</a>
+</template>
+```
+
+## Component Usage
+
+```html
+<template>
+  <UseObjectUrl v-slot="url" :object="file">
+    <a :href="url">Open file</a>
+  </UseObjectUrl>
+</template>
+```

packages/core/useObjectUrl/index.ts

@@ -0,0 +1,35 @@
+import { readonly, ref, unref, watch } from 'vue-demi'
+import { tryOnScopeDispose } from '@vueuse/shared'
+import type { MaybeRef } from '@vueuse/shared'
+
+/**
+ * Reactive URL representing an object.
+ *
+ * @see https://vueuse.org/useObjectUrl
+ * @param object
+ */
+export function useObjectUrl(object: MaybeRef<Blob | MediaSource | undefined>) {
+  const url = ref<string | undefined>()
+
+  const release = () => {
+    if (url.value)
+      URL.revokeObjectURL(url.value)
+
+    url.value = undefined
+  }
+
+  watch(
+    () => unref(object),
+    (newObject) => {
+      release()
+
+      if (newObject)
+        url.value = URL.createObjectURL(newObject)
+    },
+    { immediate: true },
+  )
+
+  tryOnScopeDispose(release)
+
+  return readonly(url)
+}