如何处理捕获 function？

Question

我在cloud firestor中创建了一个数据库，所以现在我想通过输入字段向其中添加一些信息，当输入字段为空信息时存储并捕获问题function不起作用，我该如何解决它function 工作。

这是代码：

HTML：

<div class="container"> 
          <input  type="text" placeholder="Enter the country" id="country-field"  required>
          <p class="selectPar">Enter City</p>
          <input type="text" placeholder="Enter the city" id="city-field" required>
          <p class="selectPar">Enter the place name</p>
          <input type="text" placeholder="Enter the place name" id="placename-field" required>
          <p class="selectPar">Enter Address</p>
          <input type="text" placeholder="Enter the address" id="address-field" required>
          </div>
        </div>
        <div id="btnFrmAlignSec">
          <button id="btnFrm" type="button" onclick="AddToDataBase()">Send to admin</button>
        </div>

Javascript

function AddToDataBase(){

  var inputCountry = document.getElementById("country-field").value;
  var inputCity = document.getElementById("city-field").value;
  var inputAddress = document.getElementById("address-field").value;
  var inputNameofPlace = document.getElementById("placename-field").value;

  // Add a new document in collection "cities"
   db.collection("UsersShare").doc().set({

    name:inputNameofPlace,
    city:inputCity,
    country:inputCountry,
    address:inputAddress,

  })

  .then(function() {
    console.log("Document successfully written!");
    document.getElementById("reply").style.display="inline";  
  })
  .catch(function(error) {
    console.error("Error writing document: ", error);
  });
}

Answer 1

if(inputCountry.trim() && inputCity.trim() && inputAddress.trim() && 
   inputNameOfPlace.trim()){
  // Add a new document in collection 
  // your code
} else {
 // fields are empty --- error message
}

Answer 2

您可以事先检查字段是否为空，如果不是，则对数据库进行操作，否则将错误记录到控制台，就像您的 catch function 所做的那样：

if(inputCountry && inputCity && inputAddress && inputNameOfPlace){
    db.coll.....
} else {
    console.error('Field(s) are empty');
}