Question

我对以下承诺链有疑问：

Parse.Promise.as().then(function() {
        return query.first({useMasterKey: true});
      }).then(function(requestData) {
          if (!requestData) {
              return signUp(fb_ID,fb_accessToken)
          } else {
              return signIn(fb_ID,fb_accessToken)
          }
      }).then(function(userdata){
        if (userdata.success == "true") {
           response.success(userdata)
        }
        else {
          response.error(userdata)
        }
      })

var signIn = function(fb_ID,fb_accessToken) {
console.log("signin!")
var promise = new Parse.Promise();
var TokenStorage = Parse.Object.extend("tokenStorage");
var query = new Parse.Query(TokenStorage);
query.equalTo('facebookID', fb_ID);
query.ascending('createdAt');
var password;
var username;
var output = {};
var user;
// Check if this ID has previously logged in, using the master key
query.first({ useMasterKey: true }).then(function(tokenData) {

    // Update the accessToken if it is different.
    if (fb_accessToken !== tokenData.get('fb_accessToken')) {
        console.log('1')
        user = tokenData.get('user');
        user.fetch({
          success: function(data) {
              username = data.get('username')
              tokenData.set('fb_accessToken', fb_accessToken);
              /*
              password = new Buffer(24);
              _.times(24, function(i) {
                password.set(i, _.random(0, 255));
                password = password.toString('base64')
              })
              */
              password = (Date.now().toString(36) + Math.random().toString(36).substr(2, 10)).toUpperCase();

              user.setPassword(password);
              tokenData.set('password',password)
              tokenData.set('username',username)

          }         

        }).then(function(){
            tokenData.save(null, { useMasterKey: true }).then(function(tokenuser) {
                user.save();
                return Parse.User.logIn(username, password);
            }).then(function(data) {
                // Return the user object.
                output.success = true
                output.isnewuser = false
                output.username = username;
                output.password = password;
                output.fb_accessToken = fb_accessToken;
                //return Parse.Promise.as(output);
                promise.resolve(output)
                //return promise
            });
        })

    } else {
       console.log('2')
        Parse.Promise.as().then(function() {
            username = tokenData.get('username');
            password = tokenData.get('password');
        }).then(function(){
            Parse.User.logIn(username, password)
            .then(function(data) {
                // Return the user object
                output.success = true
                output.isnewuser = false
                output.username = username;
                output.password = password;
                output.fb_accessToken = fb_accessToken;
                console.log('oo'+JSON.stringify(output))
                //return Parse.Promise.as(output);
                promise.resolve(output)

            });
        })

    }
})
return promise
}

var signUp = function(fb_ID,fb_accessToken) {
console.log("signup")
ExtendFacebookAccessToken(fb_accessToken).then(function(new_fb_accessToken){
        var TokenStorage = Parse.Object.extend("tokenStorage");
        var restrictedAcl = new Parse.ACL();
        restrictedAcl.setPublicReadAccess(false);
        restrictedAcl.setPublicWriteAccess(false);
        var user = new Parse.User();

        // Generate a random username and password.
        /*var username = new Buffer(24);
        var password = new Buffer(24);
        _.times(24, function(i) {
          username.set(i, _.random(0, 255));
          password.set(i, _.random(0, 255));
        });
        */
        var username = (Date.now().toString(36) + Math.random().toString(36).substr(2, 10)).toUpperCase();
        var password = (Date.now().toString(36) + Math.random().toString(36).substr(2, 10)).toUpperCase();

        user.set("username", username.toString('base64'));
        user.set("password", password.toString('base64'));
        // Sign up the new User
        return user.signUp().then(function(user) {
          console.log('user'+JSON.stringify(user))
          // create a new TokenStorage object to store the user+GitHub association.
          var ts = new TokenStorage();
          ts.set('facebookID', fb_ID);
          ts.set('fb_accessToken', new_fb_accessToken);
          ts.set('username',username)
          ts.set('password',password)
          ts.set('user', user);

          ts.setACL(restrictedAcl);
          // Use the master key because TokenStorage objects should be protected.
          return ts.save(null, { useMasterKey: true });
        }).then(function(tokenStorage) {
            var output
            var promise = new Parse.Promise();
            output.username = username;
            output.password = password;
            output.process = "signup";
            output.fb_accessToken = new_fb_accessToken;
            output.success = true;
            output.isnewuser = true
            promise.resolve(output);
            return promise
        });
    })   
}

SignUp和SignIn都返回一个promise，但问题是最后一个（'then（function（userdata）...'）在SignUp和SignIn返回'userdata'之前执行。我认为前面的返回SignUp或SignIn函数足以强制最后一个承诺等待userdata，但事实并非如此。任何想法？

Answer 1

您的注册方法未返回承诺。相反，您最有可能获得立即解决的undefined

变化：

var signUp = function(fb_ID,fb_accessToken) {
console.log("signup")
ExtendFacebookAccessToken(fb_accessToken).then(function(new_fb_accessToken)

要：

var signUp = function(fb_ID,fb_accessToken) {
console.log("signup")
return ExtendFacebookAccessToken(fb_accessToken).then(function(new_fb_accessToken)

请拜托，缩进你的代码:(

Javascript承诺不按顺序执行

1 个答案: