javascript - 提交表单并使用快照检索数据后，防止在未经身份验证的情况下在 Firebase 应用程序中重复邮件 ID 和电话号码

Question

我试图防止电子邮件 ID 和电话号码重复，因此在提交表单后我首先检查数据库中的电子邮件 ID 和电话号码。如果其中任何一个存在，它应该显示错误消息 email already exists in the database 否则它应该将数据推送到 firebase 实时数据库。我的申请在第一次提交表格时工作正常。如果我第二次提交具有新值的表单，数据将被添加两次。如果我第 3 次提交具有新值的表单，这些值将被提交 3 次并被推送到我的 firebase 数据库中，甚至它会抛出错误消息。它从第二次提交具有新值的表单开始进入 if 和 else 条件。任何修复，请帮助我。

下面是我试过的代码

firebase.initializeApp(firebaseConfig);
// Listen for form submit 
document.getElementById('contactform1').addEventListener('submit', submitForm);
// Submit form 
function submitForm(e) {
  e.preventDefault();
  // Get values 
  var fname = getInputVal('fname');
  var lname = getInputVal('lname');
  var newEmail = getInputVal('email');
  var newPhone = getInputVal('phone');
  var newskills = getInputVal('skills');
  var newjobId = getInputVal('jid');
  var newlinkedin = getInputVal('linkedin');
  var newgithub = getInputVal('github');
  var newlocation = getInputVal('location');

  saveMessage(fname, lname, newEmail, newskills, newPhone, newjobId, newlinkedin, newgithub, newlocation);
}

function saveMessage(fname, lname, newEmail, skills, newPhone, jobId, linkedin, github, location) {
  let ref = firebase.database().ref().child('self/data/');
  ref.once('value', snap => {
    if (snap.exists()) {
      snap.forEach(childSnapshot => {
        var email = childSnapshot.child('email').val();
        var phone = childSnapshot.child('phone').val();
        console.log(status);
        if (newEmail.trim() === email.trim() || newPhone.trim() === phone.trim()) { //check if email exists 
          console.log("email already exists in the database");
        } else {
          console.log('hello');
          firebase.database().ref().child('self/data/').push().set({
            name: fname + " " + lname,
            email: email,
            phone: phone,
            skills: skills,
            jobId: jobId,
            linkedin: linkedin,
            github: github,
            location: location
          });
        }
      });
    } else {
      firebase.database().ref().child('self/data/').push().set({
        name: fname + " " + lname,
        email: email,
        phone: phone,
        skills: skills,
        jobId: jobId,
        linkedin: linkedin,
        github: github,
        location: location
      });
    }
  });
}

// Function to get get form values 
function getInputVal(id) {
  return document.getElementById(id).value;
}

Answer 1

是的，循环内部似乎存在逻辑问题，请尝试这种方式:

 function saveMessage(fname, lname, newEmail, skills, newPhone, jobId, linkedin, github, location) {
    let ref = firebase.database().ref().child('self/data/');
    ref.once('value', snap => {
      let isDuplicated = false;
    if (snap.exists()) {
      snap.forEach(childSnapshot => {
        var email = childSnapshot.child('email').val();
        var phone = childSnapshot.child('phone').val();
        console.log(status);
        if (newEmail.trim() === email.trim() || newPhone.trim() === phone.trim()) { //check if email exists 
          isDuplicated = true;
        } 
      });
    }
    if (snap.exists() && !isDuplicated) {
      firebase.database().ref().child('self/data/').push().set({
        name: fname + " " + lname,
        email: email,
        phone: phone,
        skills: skills,
        jobId: jobId,
        linkedin: linkedin,
        github: github,
        location: location
      });
    }
    });
    }