init

components/mp-html/img-cache/index.js

@@ -0,0 +1,138 @@
+const data = {
+  name: 'imgcache',
+  prefix: 'imgcache_'
+}
+function ImgCache (vm) {
+  this.vm = vm // 保存实例在其他周期使用
+  this.i = 0 // 用于标记第几张图
+  vm.imgCache = {
+    get list () {
+      return uni
+        .getStorageInfoSync()
+        .keys.filter((key) => key.startsWith(data.prefix))
+        .map((key) => key.split(data.prefix)[1])
+    },
+    get (url) {
+      return uni.getStorageSync(data.prefix + url)
+    },
+    delete (url) {
+      const path = uni.getStorageSync(data.prefix + url)
+      if (!path) return false
+      plus.io.resolveLocalFileSystemURL(path, (entry) => {
+        entry.remove()
+      })
+      uni.removeStorageSync(data.prefix + url)
+      return true
+    },
+    async add (url) {
+      const filename = await download(url)
+      if (filename) {
+        uni.setStorageSync(data.prefix + url, filename)
+        return 'file://' + plus.io.convertLocalFileSystemURL(filename)
+      }
+      return null
+    },
+    clear () {
+      uni
+        .getStorageInfoSync()
+        .keys.filter((key) => key.startsWith(data.prefix))
+        .forEach((key) => {
+          uni.removeStorageSync(key)
+        })
+
+      plus.io.resolveLocalFileSystemURL(`_doc/${data.name}/`, (entry) => {
+        entry.removeRecursively(
+          (entry) => {
+            console.log(`${data.name}缓存删除成功`, entry)
+          },
+          (e) => {
+            console.log(`${data.name}缓存删除失败`, e)
+          }
+        )
+      })
+    }
+  }
+}
+
+// #ifdef APP-PLUS
+ImgCache.prototype.onParse = function (node, parser) {
+  // 启用本插件 && 解析图片标签 && 拥有src属性 && 是网络图片
+  if (
+    this.vm.ImgCache &&
+    node.name === 'img' &&
+    node.attrs.src &&
+    /^https?:\/\//.test(node.attrs.src)
+  ) {
+    const src = node.attrs.src
+    node.attrs.src = ''
+    node.attrs.i = this.vm.imgList.length + this.i++
+    parser.expose()
+
+    async function getUrl (path) {
+      if (await resolveFile(path)) return path
+      const filename = await download(src)
+      filename && uni.setStorageSync(data.prefix + src, filename)
+      return filename
+    }
+
+    uni.getStorage({
+      key: data.prefix + src,
+      success: async (res) => {
+        const path = await getUrl(res.data)
+        const url = path
+          ? 'file://' + plus.io.convertLocalFileSystemURL(path)
+          : src
+        node.attrs.src = url
+        this.vm.imgList[node.attrs.i] = path || src
+      },
+      fail: async () => {
+        const path = await getUrl()
+        const url = path
+          ? 'file://' + plus.io.convertLocalFileSystemURL(path)
+          : src
+        node.attrs.src = url
+        this.vm.imgList[node.attrs.i] = path || src
+      }
+    })
+  }
+}
+
+const taskQueue = new Set()
+
+function download (url) {
+  return new Promise((resolve) => {
+    if (taskQueue.has(url)) return
+    taskQueue.add(url)
+    const suffix = /.+\.(jpg|jpeg|png|bmp|gif|webp)/.exec(url)
+    const name = `${makeid(8)}_${Date.now()}${suffix ? '.' + suffix[1] : ''}`
+    const task = plus.downloader.createDownload(
+      url,
+      { filename: `_doc/${data.name}/${name}` },
+      (download, status) => {
+        taskQueue.delete(url)
+        resolve(status === 200 ? download.filename : null)
+      }
+    )
+    task.start()
+  })
+}
+
+// 判断文件存在
+function resolveFile (url) {
+  return new Promise((resolve) => {
+    plus.io.resolveLocalFileSystemURL(url, resolve, () => resolve(null))
+  })
+}
+
+// 生成uuid
+function makeid (length) {
+  let result = ''
+  const characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'
+  for (let i = 0; i < length; i++) {
+    result += characters.charAt(Math.floor(Math.random() * characters.length))
+  }
+  return result
+}
+// #endif
+
+export default ImgCache