Recently, because I wanted to make a small program, I studied js. I used to work on the server side.
The login part of the small program was more complicated. Later, the callbacks were nested too deeply, so I kept learning, and later I discovered promises,
But I encountered a question when making promises:
I now encapsulate the login process into a method (loginFlow), which continuously then, then, then, catch. But I have another function to get the user's content list, then I should How to make this action execute after logging in?
Should I add a callback to loginFlow?
Or should I nest a layer of promises in the outer layer of loginFlow?
It doesn’t always feel very beautiful. Is there something wrong with my understanding?
I am new to js and promises. , looking for expert guidance.
The following is the code, loginFlow is the encapsulated login sequence
This._login inside is the encapsulated wx.login, which returns a promise
This._http inside is the encapsulated wx.request and returns the promise
loginFlow: function() {
var that = this;
this._login({}).then(function(res) {
// 用 code 去获取 session
let options = {
url: that.globalData.apiDomain + '/mina/session',
method: 'GET',
data: {
code: res.code
}
}
return that._http(options);
}).then(function(res) {
// 把 session 放入 storage, 并且获取用户信息
wx.setStorageSync('session', res.data.session);
return this._getUserInfo({});
}).then(function(resUser) {
// 把用户信息上传
let options = {
url: that.globalData.apiDomain + '/mina/user/info',
method: 'POST',
data: resUser
};
return that._http(options);
}).then(function(res) {
// 上传信息结果成功
if (res.statusCode == 200) {
// 把用户信息保存到本地
} else {
// 程序逻辑返回了失败, 提示?
return Promise.reject(new Error("程序逻辑错误, 保存用户信息失败"));
}
}).catch(function(err) {
// 登录出错
that._alert("登录出错");
});
},
怪我咯2017-05-19 10:49:45
The then method accepts two parameters, you can put the final error handling together and return the promise instance
