无法在 then 方法中调用 function

Question

I am trying to call two functions one within another

commonService Components

function AddEmail(user) {
    return auth.createUserWithEmailAndPassword(user.email,user.password);    
    //createUsers(user) this way of calling is working, but i don't want to invoke like this...
}

function createUsers(user) {
    return db.collection("users").add({
        firstName: user.firstName,
        lastName:  user.lastName,
        address:  user.address,
        phoneNumber:  user.phoneNumber,
        email:  user.email,
        role:  user.role,
    });
}

register component

submits(e) { 
    e.preventDefault();
    const { user} = this.state;
        
    commonService.AddEmail(user)
    .then(() => {
        commonService.createUsers(user)
        .then(() =>{//success})
        .catch(err=> console.log(err));
    })
    .catch(err=> console.log(err));
}

The AddEmail gets executed, but not the createUsers . I've tried returning and chaining via then method too, still its not working, what am I missing?

Answer 1

Try the following with async / await .

async submit(e){
    e.preventDefault();
    const { user} = this.state;

    try {
        const userEmailAdded = await commonService.AddEmail(user);
        const userCreated = await commonService.createUsers(user);
    } catch (err) {
        console.log(err);
    }
}

Make sure to return a promise in both the function calls. If the return value is not a promise, wrap it in a promise using the following code

function AddEmail(user) {
    return new Promise((resolve, reject){
        const createdUser = auth.createUserWithEmailAndPassword(user.email,user.password);
        if(createdUser)
            return resolve(createdUser);
        else
            return reject("Error in creating user.");
    })
}

Check for any errors in console. If none, both calls passed.

Answer 2

Try to use this code.

submits(e) { 
    e.preventDefault();
    const { user} = this.state;
        
    commonService.AddEmail(user)
    .then(() => commonService.createUsers(user))
    .then(() =>{//success})
    .catch(err=> console.log(err));
}

Answer 3

return auth.createUserWithEmailAndPassword(user.email,user.password);

The returning function must be a javascript Promise to use a .then .

You can try to console.log(auth.createUserWithEmailAndPassword) whether it is a Promise or not.