Determine whether the login is invalid code

This time I will bring you the code to determine whether the login is invalid and determine whether the login is invalid. What are the precautions?. Here is a practical case. Let’s take a look.

var that = this;
        new Promise((resolve, reject) => {
            // 检查wx.login有没有失效，失效的话重新wx.login
            wx.checkSession({
                success() {
                    console.log('code', wx.getStorageSync('code'));
                    console.log('globalData', wx.getStorageSync('globalData'));
　　　　　　　　　　　　　//如果小程序再次从后台进入前台的话，用storage保存的话是有值的
　　　　　　　　　　　　　//如果用this.globalData的话来保存数据，下次从后台进入前台的话是值还是空的　
                },
                fail() {
                    wx.login({
                        success(res) {
                            wx.getUserInfo({
                                success(re) {
                                    wx.setStorageSync('code', res.code)
                                    that.globalData.code = res.code;
                                    that.globalData.userInfo = re.userInfo;
                                    wx.setStorageSync('globalData', that.globalData);
                                }
                            })
                        },
                        fail: function(err) {
                            
                        }
                    })
                }
            })
            resolve();
        }).then((res) => {
            var code=wx.getStorageSync('code');
            var globalData=wx.getStorageSync('globalData')
           
        })

First of all, wx.checkSession is to determine whether the wx.login method login state is invalid.
Thinking
wx.checkSession({
Success(){ //Login at this time The status is not invalid, so you don’t need to go to wx.login
//But according to my needs, I need to connect to the interface next, and I need the login data, but how to get the data at this time
　　　 1. If the applet enters the foreground from the background again, it will have a value if you use storage to save it
　　2. If you use this.globalData to save the data, the next time you enter the foreground from the background, the value will still be empty} ,
fail(){ wx.login()
}
})

This is my implementation idea
The code is above

I believe after reading these You have mastered the case method. For more exciting information, please pay attention to other related articles on the PHP Chinese website!

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