packages/wepy-web/src/wx.js 分析storage 的加载原理 wx.getStorage(OBJECT)

是小程序实例化后

读入内存

还是每次调用从文件系统读取

https://github.com/Tencent/wepy/blob/bd0003dca2bfb9581134e1b05d4aa1d80fc53858/packages/wepy-web/src/wx.js

/**
 * Tencent is pleased to support the open source community by making WePY available.
 * Copyright (C) 2017 THL A29 Limited, a Tencent company. All rights reserved.
 * 
 * Licensed under the MIT License (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
 * http://opensource.org/licenses/MIT
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
 */


import Vue from 'vue';
import axios from 'axios';
import {resolveQuery} from './helper/query';
import {browser, system} from './helper/device';

const callback = (type, o, name, data) => {
    if (typeof o[type] === 'function') {
        setTimeout(() => {
            if (name === 'login') {
                o[type].call(wx, {errMsg: name + ':' + (type === 'fail' ? 'fail' : 'ok'), code: data.code, data: data});
            } else if (name === 'getSystemInfo') {
                o[type].call(wx, data);
            } else {
                o[type].call(wx, {errMsg: name + ':' + (type === 'fail' ? 'fail' : 'ok'), data: data});
            }
        }, 0);
    }
}


let wx = window.wx || {};

wx.login = wx.login || function login (o) {
    console.error('wx.login is only implemented in browser');
};

/*** Storage ***/
wx.getStorageSync = wx.getStorageSync || function getStorageSync (v) {
    let rst = window.localStorage.getItem(v);
    try {
            rst = JSON.parse(rst);
    } catch (e) {
    }
    return rst;
};
wx.getStorage = wx.getStorage || function getStorage (o) {
    let rst = wx.getStorageSync(o.key);
    callback('success', o, 'getStorage', rst);
    callback('complete', o, 'getStorage', rst);
};
wx.setStorageSync = wx.setStorageSync || function setStorageSync (k, d) {
    if (typeof d !== 'string') {
        d = JSON.stringify(d);
    }
    window.localStorage.setItem(k, d);
};
wx.setStorage = wx.setStorage || function setStorage (o) {
    let rst;
    try {
        rst = this.setStorageSync(o.key, o.data);
        callback('success', o, 'getStorage', rst);
    } catch (e) {
        callback('fail', o, 'getStorage', rst);
    }
    callback('complete', o, 'getStorage', rst);
};
wx.getStorageInfoSync = wx.getStorageInfoSync || function getStorageInfoSync () {
    let MAX_SIZE = 5 * 1024;
    let keys = Object.keys(window.localStorage);
    return {
        currentSize: 1,
        keys: keys,
        limitSize: MAX_SIZE
    };
};
wx.getStorageInfo = wx.getStorageInfo || function getStorageInfo (o) {
    let rst = this.getStorageInfoSync();
    callback('success', o, 'getStorageInfo', rst);
    callback('complete', o, 'getStorageInfo', rst);
};
wx.removeStorageSync = wx.removeStorageSync || function removeStorageSync (k) {
    window.localStorage.removeItem(k);
};
wx.removeStorage = wx.removeStorage || function removeStorage (o) {
    let rst;
    try {
        rst = this.removeStorage(o.key);
        callback('success', o, 'getStorage', rst);
    } catch (e) {
        callback('fail', o, 'getStorage', rst);
    }
    callback('complete', o, 'getStorage', rst);
};
wx.clearStorageSync = wx.clearStorageSync || function clearStorageSync () {
    window.localStorage.clear();
};
wx.clearStorage = wx.clearStorage || function clearStorage () {
    let rst;
    try {
        rst = this.clearStorage();
    } catch (e) {
    }
};

    /***** Navigate ******/
wx.navigateTo = wx.navigateTo || function navigateTo (o) {
    window.$router.go(o.url);
};
wx.redirectTo = wx.redirectTo || function redirectTo (o) {
    window.$router.go(o.url);
};
wx.switchTab = wx.switchTab || function switchTab (o) {
    window.$router.go(o.url);
};
wx.navigateBack = wx.navigateBack || function navigateBack (o) {
    if (!o) {
        o = {};
    }
    if (o.delta)
        o.delta = -1;
    window.$router.go(o.delta);
};

    /***** System ******/
wx.getSystemInfoSync = wx.getSystemInfoSync || function getSystemInfoSync () {
    return {
        SDKVersion: '0.0.0',
        language: '-',
        model: browser(),
        pixelRatio: 0,
        platform: system(),
        screenHeight: window.screen.height,
        screenWidth: window.screen.width,
        system: system(),
        version: '0.0.0',
        windowHeight: window.innerHeight,
        windowWidth: window.innerWidth
    }
};
wx.getSystemInfo = wx.getSystemInfo || function getSystemInfo (o) {
    let rst = this.getSystemInfoSync();
    callback('success', o, 'getSystemInfo', rst);
    callback('complete', o, 'getSystemInfo', rst);
};
wx.canIUse = wx.canIUse || function canIUse () {
    return true;
};

    /****** Network ***********/
wx.getNetworkType = wx.getNetworkType || function getNetworkType () {
    return 'unkown';
};

    /****** NavigationBar *******/
wx.setNavigationBarTitle = wx.setNavigationBarTitle || function setNavigationBarTitle (o) {
    document.title = o.title;
    callback('success', o, 'setNavigationBarTitle', null);
    callback('complete', o, 'setNavigationBarTitle', null);
};

wx.makePhoneCall = wx.makePhoneCall || function makePhoneCall (o) {
    window.location = 'tel:' + o.phoneNumber;
    callback('success', o, 'makePhoneCall', null);
    callback('complete', o, 'makePhoneCall', null);
};

wx.hideKeyboard = wx.hideKeyboard || function hideKeyboard () {
    // http://stackoverflow.com/questions/8335834/how-can-i-hide-the-android-keyboard-using-javascript
    setTimeout(() => {
        let field = document.createElement('input');
        field.setAttribute('type', 'text');
        field.setAttribute('style', 'position:absolute; top: 0px; opacity: 0; -webkit-user-modify: read-write-plaintext-only; left:0px;');
        document.body.appendChild(field);

        field.onfocus = () => {
            setTimeout(() => {
                field.setAttribute('style', 'display:none;');
                setTimeout(() => {
                    document.body.removeChild(field);
                    document.body.focus();
                }, 14);

            }, 200);
        };
        field.focus();
    }, 50);
};

['getUserInfo', 'switchTab', 'showNavigationBarLoading', 'hideNavigationBarLoading', 'createAnimation', 'requestPayment', 'chooseImage', 'showModal', 'showToast', 'showActionSheet'].forEach(k => {
    if (!wx[k]) {
        wx[k] = (o = {}) => {
            console.error(`wx.${k} is not supported in browser or you did add it in config.`);
            callback('fail', o, k, null);
            callback('complete', o, k, null);
        };
    }
});

wx.request = wx.request ? wx.request : function request (options) {
    let handlers = {};
    ['success', 'fail', 'complete', 'beforeAll', 'beforeSuccess', 'afterSuccess', 'beforeCancel', 'cancel', 'afterCancel', 'beforeFail', 'afterFail', 'afterAll'].forEach(k => {
            handlers[k] = options[k];
            delete options[k];
    });
    let rst = {errMsg: 'request', statusCode: 0, data: undefined};
    if (!options.method || options.method.toLowerCase() === 'get') {
        options.params = options.data;
        delete options.data;
    }
    axios(options).then(res => {
        rst.errMsg = rst.errMsg + ':ok';
        rst.statusCode = res.status;
        rst.data = res.data;

        // WAService.js
        if (typeof handlers.beforeAll === 'function') {
                handlers.beforeAll(res);
        }
        if (typeof handlers.beforeSuccess === 'function') {
                handlers.beforeSuccess(res);
        }
        if (typeof handlers.success === 'function') {
                handlers.success(res);
        }
        if (typeof handlers.afterSuccess === 'function') {
                handlers.afterSuccess(res);
        }
        if (typeof handlers.complete === 'function') {
                handlers.complete(res);
        }
        if (typeof handlers.afterAll === 'function') {
                handlers.afterAll(res);
        }
    }).catch(res => {
        if (typeof handlers.beforeAll === 'function') {
                handlers.beforeAll(res);
        }
        if (axios.isCancel(res)) {
            rst.errMsg = rst.errMsg + ':cancel';
            if (typeof handlers.fail === 'function') {
                    handlers.fail(res);
            }
            if (typeof handlers.beforeCancel === 'function') {
                    handlers.beforeCancel(res);
            }
            if (typeof handlers.cancel === 'function') {
                    handlers.cancel(res);
            }
            if (typeof handlers.afterCancel === 'function') {
                    handlers.afterCancel(res);
            }
        } else {
            rst.errMsg = rst.errMsg + ':fail';
            if (typeof handlers.beforeFail === 'function') {
                    handlers.beforeFail(res);
            }
            if (typeof handlers.fail === 'function') {
                    handlers.fail(res);
            }
            if (typeof handlers.afterFail === 'function') {
                    handlers.afterFail(res);
            }
        }
        rst.data = res;
        if (typeof handlers.complete === 'function') {
                handlers.complete(res);
        }
        if (typeof handlers.afterAll === 'function') {
                handlers.afterAll(res);
        }
    })
};

if (typeof window !== 'undefined') {
    window.getApp = () => {
        return Vue;
    };

    window.getCurrentPages = () => {
        if (wx._currentPage)
            return [wx._currentPage];
        else 
            return [wx._currentPages[0]];
    };
}

window.wx = wx;

export default wx;

数据缓存 · 小程序 https://mp.weixin.qq.com/debug/wxadoc/dev/api/data.html#wxremovestoragesynckey

Bug & Tip

1. tip: 本地数据存储的大小限制为 10MB