Question

为什么usernameOK = 1;当我在$ .post函数后使用alert语句时，ajax函数中的语句不会保持设置？我需要一种方法来使用变量作为if语句的条件。

function validateRegistration() {
var username        = document.getElementById("userName").value;
var fname           = document.getElementById("fName").value;
var lname           = document.getElementById("lName").value;
var email           = document.getElementById("email").value;
var confirmEmail    = document.getElementById("confirmEmail").value;
var password        = document.getElementById("userpass").value;
var confirmPass     = document.getElementById("confirmPassword").value;
    var usernameOK = 0;

    $.post("action.php", { field: 'doesUsernameExist', username: username },  
    function(result){    //if the result is 1  
       if(result == 1){  //show that the username is available 
           usernameSuc.innerHTML= username + " is Available.";  
           var usernameOK=1;
        }else if(result == 0){  //show that the username is NOT available 
           usernameErr.innerHTML="User name: "+username+" is not  
           available.";             
        } else {
           usernameErr.innerHTML="Something is Wrong"; 
        }
    });  

    alert("usernameOK: "+usernameOK);  //This doesn't work. only prints a zero, never 1

    if (usernameOK == 1) {
       if ((username.length > 5) && (!(/[^a-zA-Z0-9_-]/.test(username)))){
           if((fname != "") && (lname != "")){
               if((email != "") && (email == confirmEmail)){
                   if (((email.indexOf(".") > 0) && (email.indexOf("@") > 0)) 
                   && !/[^a-zA-Z0-9.@_-]/.test(email)){
                       if ((password.length > 7) && (/[a-z]/.test(password))
                       && (/[A-Z]/.test(password)) && (/[0-9]/.test(password))){
                           if (password == confirmPass) {

document.getElementById("submit").className = "btn btn-success";
document.getElementById("submit").removeAttribute("disabled");
                           }
                        }
                    }
                }
            }
       }
  } else {
     document.getElementById("submit").className = "btn btn-success disabled";
  }

}

Answer 1

找出解决方案。以为我会发布它，以防它可以帮助别人。更改了顺序并在所有条件if语句中移动了ajax，因此它是最后检查而不是第一个。

function validateRegistration() {
    var username        = document.getElementById("userName").value;
    var fname       = document.getElementById("fName").value;
    var lname       = document.getElementById("lName").value;
    var email       = document.getElementById("email").value;
    var confirmEmail    = document.getElementById("confirmEmail").value;
    var password        = document.getElementById("userpass").value;
    var confirmPass     = document.getElementById("confirmPassword").value;

    if ((username.length > 5) && (!(/[^a-zA-Z0-9_-]/.test(username)))){
    if((fname != "") && (lname != "")){
        if((email != "") && (email == confirmEmail)){
            if (((email.indexOf(".") > 0) 
                               && (email.indexOf("@") > 0))    
                               && !/[^a-zA-Z0-9.@_-]/.test(email)){
                if ((password.length > 7) 
                                        && (/[a-z]/.test(password)) 
                                        && (/[A-Z]/.test(password)) 
                                        && (/[0-9]/.test(password))){
                    if (password == confirmPass) {

       $.ajax({
      type: "POST",
      url: "action.php",
      data: {field: 'doesUsernameExist', username: username },
      async: false,
      success: function (result) {
    if(result == 1) {
        document.getElementById("submit").className = "btn btn-success";
        document.getElementById("submit").removeAttribute("disabled");

            } else {
    document.getElementById("submit").className = "btn btn-success disabled";
    document.getElementById("submit").setAttribute('disabled', true);
    }
      },
      error: function (result) {
    pass = "error"
    alert("There was an error with the database");
      }                     
       });                          
                        }
                    }
                }
            }   
        }
    } else {
        document.getElementById("submit").className = "btn btn-success disabled";
        document.getElementById("submit").setAttribute('disabled', true);
    }

}

在ajax函数中设置一个变量

1 个答案: