app.js

const config = require('./config')

global.isDemo = true
App({
  onLaunch(opts) {
    const that = this;
    wx.getBackgroundFetchData({
      fetchType: 'pre',
      success(res) {
        that.globalData.backgroundFetchData  = res;
        console.log('读取预拉取数据成功')
      },
      fail() {
        console.log('读取预拉取数据失败')
        wx.showToast({
          title: '无缓存数据',
          icon: 'none'
        })
      },
      complete() {
        console.log('结束读取')
      }
    })
    console.log('App Launch', opts)
    if (!wx.cloud) {
      console.error('请使用 2.2.3 或以上的基础库以使用云能力')
    } else {
      wx.cloud.init({
        env: config.envId,
        traceUser: true,
      })
    }
    wx.setBackgroundFetchToken({
      token: 'getBackgroundFetchToken',
    })

  },
  onShow(opts) {
    console.log('App Show', opts)
  },
  onHide() {
    console.log('App Hide')
  },
  globalData: {
    hasLogin: false,
    openid: null,
    backgroundFetchData: null,
  },
  // lazy loading openid
  getUserOpenId(callback) {
    const self = this

    if (self.globalData.openid) {
      callback(null, self.globalData.openid)
    } else {
      wx.login({
        success(data) {
          wx.request({
            url: config.openIdUrl,
            data: {
              code: data.code
            },
            success(res) {
              console.log('拉取openid成功', res)
              self.globalData.openid = res.data.openid
              callback(null, self.globalData.openid)
            },
            fail(res) {
              console.log('拉取用户openid失败，将无法正常使用开放接口等服务', res)
              callback(res)
            }
          })
        },
        fail(err) {
          console.log('wx.login 接口调用失败，将无法正常使用开放接口等服务', err)
          callback(err)
        }
      })
    }
  },
  // 通过云函数获取用户 openid，支持回调或 Promise
  getUserOpenIdViaCloud() {
    return wx.cloud.callFunction({
      name: 'wxContext',
      data: {}
    }).then(res => {
      this.globalData.openid = res.result.openid
      return res.result.openid
    })
  }
})