uniapp-通用组件-可缓存图片组件

/** * 文件名缓存 */ let _FILE_CACHE_KEY = 'DEFAULT_FILE_CACHE'; let _FILE_MAP_ = null; let _DOWNLOAD_MAP_ = new Map(); /** * 获取缓存数据 */ const _getStorage = () => { let result = uni.getStorageSync(_FILE_CACHE_KEY); if (!result) { uni.setStorage({ key: _FILE_CACHE_KEY, data: [] }) result = []; } return result; } const isEmpty = (str) => { return str === null || str === undefined || !str } /** * 初始化 * key--String--本地缓存key，分成了图片，文件，等等 * expiration--Number--过期时间，touchDate距今expiration+1天，就删除 */ const init = ({ key, expiration }) => { // 设置key if (!isEmpty(key) && typeof key === 'string') { _FILE_CACHE_KEY = key; } // 获取缓存数据 // let array = _getStorage(); let array = []; // 根据时间判断排序, 删除不再使用的数据 orderAndFilterFileList(array, expiration); // 获取文件id，文件filePath，map _FILE_MAP_ = getFileMap(array); console.log('_FILE_MAP_', _FILE_MAP_) return _FILE_MAP_; } /** * 获取fileId，filePath对应map * @param {Array} fileList */ const getFileMap = (fileList) => { let map = new Map(); fileList.forEach((fileItem) => { map.set(fileItem.fileId, fileItem.filePath); }) return map; } /** * 根据时间判断排序, 删除不再使用的数据 */ const orderAndFilterFileList = (fileList, expiration) => { let index = -1; if (fileList && Array.isArray(fileList)) { fileList.sort((a, b) => { return b.touchDate - a.touchDate; }) let boundaryDate = new Date().setHours(24, 0, 0, 0) - expiration * 24 * 60 * 60 * 1000; for (var i = 0; i < fileList.length; i++) { let element = fileList[i]; let touchDate = element.touchDate; if (touchDate <= boundaryDate) { index = i; } } } if (index > 0) { fileList = fileList.slice(0, index); let discardList = fileList.slice(index); discardList.forEach(fileItem => { uni.removeSavedFile({ filePath: fileItem.filePath }) }) } } /** * 缓存中新增文件 */ const addFile = (fileId, savedFilePath) => { uni.getStorage({ key: _FILE_CACHE_KEY, complete: (res) => { let array = []; if (res.data) { array = res.data; } array.push({ fileId, filePath: savedFilePath, touchDate: new Date().getTime(), }) uni.setStorage({ key: _FILE_CACHE_KEY, data: array, success: (res) => { } }) } }) } /** * 摸一下文件，更新文件缓存的touchDate * @param {String} fileId */ const touchFile = (fileId) => { if (_FILE_MAP_.get(fileId)) { uni.getStorage({ key: _FILE_CACHE_KEY, success: (res) => { let array = []; if (res.data) { array = res.data; } array.map((item) => { if (item.fileId === fileId) { item.touchDate = new Date().getTime(); } return item; }) uni.setStorage({ key: _FILE_CACHE_KEY, data: array }) } }) } else { throw Error(`无法touchFile，找不到fileId=${fileId}对应的文件`); } } /** * */ const saveFile = (fileId, fileUrl, startDownload) => { return new Promise((resolve, reject) => { if (_FILE_MAP_.get(fileId)) { touchFile(fileId); resolve(_FILE_MAP_.get(fileId)); } else { let arr = _DOWNLOAD_MAP_.get(fileId); if (!arr) { _DOWNLOAD_MAP_.set(fileId, []); console.log('_DOWNLOAD_MAP_', _DOWNLOAD_MAP_) let downloadTask = uni.downloadFile({ url: fileUrl, complete(data) { if (data && data.statusCode === 200) { // #ifdef APP-PLUS uni.saveFile({ tempFilePath: data.tempFilePath, success(res) { _FILE_MAP_.set(fileId, res.savedFilePath); addFile(fileId, res.savedFilePath); fireEvents(fileId, data.tempFilePath); resolve(res.savedFilePath); }, fail(err) { reject(err); } }) // #endif // #ifdef H5 _FILE_MAP_.set(fileId, data.tempFilePath); fireEvents(fileId, data.tempFilePath); resolve(data.tempFilePath); // #endif } else { fireEvents(fileId, null); reject(data); } } }) } else { // 同时多个下载，保存到map arr.push({ resolve, reject }); } startDownload && startDownload(downloadTask); } }) } /** * 同时多个下载，成功event触发 */ const fireEvents = (fileId, filePath) => { let arr = _DOWNLOAD_MAP_.get(fileId); if (arr && arr.length) { arr.forEach((item) => { if (filePath) { item.resolve && item.resolve(filePath); } else { item.reject && item.reject(); } }) _DOWNLOAD_MAP_.delete(fileId); } } /** * 获取文件缓存路径 */ const getCacheFilePath = (fileId) => { return _FILE_MAP_.get(fileId) } export default { init, saveFile, touchFile, getCacheFilePath }