feat: migrate to composition api (nuxt#571)

Co-authored-by: Pooya Parsa <[email protected]>

playground/pages/bg.vue

@@ -0,0 +1,25 @@
+<template>
+  <div class="preview" />
+</template>
+
+<script lang="ts" setup>
+const $img = useImage()
+
+const bg = computed(() => {
+  const imgUrl = $img('/images/colors.jpg', {
+    width: 300,
+    height: 300,
+    quality: 80
+  })
+
+  return `url('${imgUrl}')`
+})
+</script>
+
+<style>
+.preview {
+  width: 300px;
+  height: 300px;
+  background-image: v-bind(bg);
+}
+</style>

src/module.ts

@@ -1,5 +1,5 @@
 import { withLeadingSlash } from 'ufo'
-import { defineNuxtModule, addTemplate, createResolver, addComponent, addPlugin } from '@nuxt/kit'
+import { defineNuxtModule, addTemplate, addAutoImport, createResolver, addComponent, addPlugin } from '@nuxt/kit'
 import { resolveProviders, detectProvider } from './provider'
 import type { ImageProviders, ImageOptions, InputProvider, CreateImageOptions } from './types'
 
@@ -85,14 +85,19 @@ export default defineNuxtModule<ModuleOptions>({
     nuxt.options.alias['#image'] = runtimeDir
     nuxt.options.build.transpile.push(runtimeDir)
 
+    addAutoImport({
+      name: 'useImage',
+      from: resolver.resolve('runtime/composables')
+    })
+
     // Add components
     addComponent({
       name: 'NuxtImg',
-      filePath: resolver.resolve('./runtime/components/nuxt-img.vue')
+      filePath: resolver.resolve('./runtime/components/nuxt-img')
     })
     addComponent({
       name: 'NuxtPicture',
-      filePath: resolver.resolve('./runtime/components/nuxt-picture.vue')
+      filePath: resolver.resolve('./runtime/components/nuxt-picture')
     })
 
     // Add runtime options

src/runtime/components/_base.ts

@@ -0,0 +1,107 @@
+import { computed } from 'vue'
+import type { ExtractPropTypes } from 'vue'
+import { parseSize } from '../utils'
+
+export const baseImageProps = {
+  // input source
+  src: { type: String, required: true },
+
+  // modifiers
+  format: { type: String, default: undefined },
+  quality: { type: [Number, String], default: undefined },
+  background: { type: String, default: undefined },
+  fit: { type: String, default: undefined },
+  modifiers: { type: Object as () => Record<string, any>, default: undefined },
+
+  // options
+  preset: { type: String, default: undefined },
+  provider: { type: String, default: undefined },
+
+  sizes: { type: [Object, String] as unknown as () => string | Record<string, any>, default: undefined },
+  preload: { type: Boolean, default: undefined },
+
+  // <img> attributes
+  width: { type: [String, Number], default: undefined },
+  height: { type: [String, Number], default: undefined },
+  alt: { type: String, default: undefined },
+  referrerpolicy: { type: String, default: undefined },
+  usemap: { type: String, default: undefined },
+  longdesc: { type: String, default: undefined },
+  ismap: { type: Boolean, default: undefined },
+  loading: { type: String, default: undefined },
+  crossorigin: {
+    type: [Boolean, String] as unknown as () => 'anonymous' | 'use-credentials' | boolean,
+    default: undefined,
+    validator: val => ['anonymous', 'use-credentials', '', true, false].includes(val)
+  },
+  decoding: {
+    type: String as () => 'async' | 'auto' | 'sync',
+    default: undefined,
+    validator: val => ['async', 'auto', 'sync'].includes(val)
+  }
+}
+
+export interface BaseImageAttrs {
+  width?: number
+  height?: number
+  alt?: string
+  referrerpolicy?: string
+  usemap?: string
+  longdesc?: string
+  ismap?: boolean
+  crossorigin?: '' | 'anonymous' | 'use-credentials'
+  loading?: string
+  decoding?: 'async' | 'auto' | 'sync'
+}
+
+export interface BaseImageModifiers {
+  width?: number
+  height?: number
+  format?: string
+  quality?: string | number
+  background?: string
+  fit?: string
+  [key: string]: any
+}
+
+export const useBaseImage = (props: ExtractPropTypes<typeof baseImageProps>) => {
+  const options = computed(() => {
+    return {
+      provider: props.provider,
+      preset: props.preset
+    }
+  })
+
+  const attrs = computed<BaseImageAttrs>(() => {
+    return <BaseImageAttrs>{
+      width: parseSize(props.width),
+      height: parseSize(props.height),
+      alt: props.alt,
+      referrerpolicy: props.referrerpolicy,
+      usemap: props.usemap,
+      longdesc: props.longdesc,
+      ismap: props.ismap,
+      crossorigin: props.crossorigin === true ? 'anonymous' : props.crossorigin || undefined,
+      loading: props.loading,
+      decoding: props.decoding
+    }
+  })
+
+  const modifiers = computed<BaseImageModifiers>(() => {
+    return <BaseImageModifiers> {
+      ...props.modifiers,
+      width: parseSize(props.width),
+      height: parseSize(props.height),
+      format: props.format,
+      quality: props.quality,
+      background: props.background,
+      fit: props.fit
+    }
+  })
+
+  return {
+    options,
+    attrs,
+    modifiers
+  }
+}

src/runtime/components/nuxt-img.ts

@@ -0,0 +1,109 @@
+import { h, defineComponent } from 'vue'
+import { useImage } from '../composables'
+import { parseSize } from '../utils'
+import { baseImageProps, useBaseImage } from './_base'
+import { useHead } from '#imports'
+
+export const imgProps = {
+  ...baseImageProps,
+  placeholder: { type: [Boolean, String, Number, Array], default: undefined }
+}
+
+export default defineComponent({
+  name: 'NuxtImg',
+  props: imgProps,
+  setup: (props, ctx) => {
+    const $img = useImage()
+    const _base = useBaseImage(props)
+
+    const placeholderLoaded = ref(false)
+
+    type AttrsT = typeof _base.attrs.value & {
+      sizes?: string
+      srcset?: string
+    }
+
+    const sizes = computed(() => $img.getSizes(props.src, {
+      ..._base.options.value,
+      sizes: props.sizes,
+      modifiers: {
+        ..._base.modifiers.value,
+        width: parseSize(props.width),
+        height: parseSize(props.height)
+      }
+    }))
+
+    const attrs = computed(() => {
+      const attrs: AttrsT = _base.attrs.value
+      if (props.sizes) {
+        attrs.sizes = sizes.value.sizes
+        attrs.srcset = sizes.value.srcset
+      }
+      return attrs
+    })
+
+    const placeholder = computed(() => {
+      let placeholder = props.placeholder
+      if (placeholder === '') { placeholder = true }
+      if (!placeholder || placeholderLoaded.value) { return false }
+      if (typeof placeholder === 'string') { return placeholder }
+
+      const size = (Array.isArray(placeholder)
+        ? placeholder
+        : (typeof placeholder === 'number' ? [placeholder, placeholder] : [10, 10])) as [w: number, h: number, q: number]
+
+      return $img(props.src, {
+        ..._base.modifiers.value,
+        width: size[0],
+        height: size[1],
+        quality: size[2] || 50
+      }, _base.options.value)
+    })
+
+    const mainSrc = computed(() =>
+      props.sizes
+        ? sizes.value.src
+        : $img(props.src, _base.modifiers.value, _base.options.value)
+    )
+
+    const src = computed(() => placeholder.value ? placeholder.value : mainSrc.value)
+
+    if (props.preload) {
+      const isResponsive = Object.values(sizes.value).every(v => v)
+      useHead({
+        link: [{
+          rel: 'preload',
+          as: 'image',
+          ...(!isResponsive
+            ? { href: src.value }
+            : {
+                href: sizes.value.src,
+                imagesizes: sizes.value.sizes,
+                imagesrcset: sizes.value.srcset
+              })
+        }]
+      })
+    }
+
+    const imgEl = ref<HTMLImageElement>(null)
+
+    onMounted(() => {
+      if (placeholder.value) {
+        const img = new Image()
+        img.src = mainSrc.value
+        img.onload = () => {
+          imgEl.value.src = mainSrc.value
+          placeholderLoaded.value = true
+        }
+      }
+    })
+
+    return () => h('img', {
+      ref: imgEl,
+      key: src.value,
+      src: src.value,
+      ...attrs.value,
+      ...ctx.attrs
+    })
+  }
+})