会话变量在使用后未更新

Question

I am trying to check the result from a function and determine where on my page it should go by using the Session Variable "alernativeRD". It goes to the correct element on the first try, but after that it keeps going only to the first element regardless of whether its right or not. After some testing I've found that "alernativeRD" does get changed every time in the PHP function, but it doesn't change in the Javascript part.

PHP PART

function firstSignInDefault(){
    global $con;
    $clubUsername= $_SESSION['clubUsername'];
    $_SESSION['alternativeRD']='false'; //sets it back to false to avoid having alternativeRD be true    for next user

    $lastName= mysqli_real_escape_string($con, $_POST['lastNameF']);
    $firstName= mysqli_real_escape_string($con, $_POST['firstNameF']);
    $memberID= mysqli_real_escape_string($con, $_POST['idNumberF']);    

    if(!(is_numeric($memberID))){
        die("<h3> Student ID must be a number </h3>"); 
    }

    $getMemberRow= mysqli_query($con, "SELECT * FROM memberstable WHERE MemberMadeID='$memberID' AND Club='$clubUsername'");  

    if(mysqli_num_rows($getMemberRow)==0){                          
        $sql="INSERT INTO memberstable (MemberMadeID,FirstName,LastName,Club)    
        VALUES ('$memberID','$firstName','$lastName', '$clubUsername')";

        $test=false;              //checks to make sure sql statement runs fine
        if(mysqli_query($con,$sql))
            $test=true;
        else {
            echo "<h3> Error running sql </h3>";
        }

        $date=date("Y-m-d h:i:sa"); 

        $getMemberRow= mysqli_query($con, "SELECT * FROM memberstable WHERE MemberMadeID='$memberID' AND Club='$clubUsername'");  
        $memberRowArray=mysqli_fetch_array($getMemberRow);
        $memberPanID=$memberRowArray['UniquePanDBID'];

        $sql2="INSERT INTO signinstable (TimeOfSignIn, UniquePanDBID, ClubUsername, FirstName, LastName) VALUES ('$date','$memberPanID','$clubUsername', '$firstName', '$lastName')"; 
        //THE FOCUS OF THIS QUESTION IS BELOW THIS COMMENT
        if(mysqli_query($con, $sql2) && $test==true){
            $_SESSION['alternativeRD']='true'; 
            echo " <h2 id='signedInPeople' >".$date. " ".$firstName ." ". $lastName ."</h2>";
        }

    }
    else {
        echo "<h3> ID Number already in use</h3>";
    }
}

JAVASCRIPT/AJAX PART

function processFSIF(){

var xmlHttp= makeXMLHTTP();

// Create some variables we need to send to our PHP file
var url = "signInDataPlace.php";

var idNumberF = document.getElementById("idNumberF").value;
var lastNameF = document.getElementById("lastNameF").value;
var firstNameF = document.getElementById("firstNameF").value;
var typeSignIn="first"; 

var vars = "idNumberF="+idNumberF +"&lastNameF="+lastNameF +"&firstNameF="+firstNameF +"&typeSignIn=" +typeSignIn;

xmlHttp.open("POST", url, true);
// Set content type header information for sending url encoded variables in the request
xmlHttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
// Access the onreadystatechange event for the XMLHttpRequest object
xmlHttp.onreadystatechange = function() {
    if(xmlHttp.readyState == 4 && xmlHttp.status == 200) {
        var return_data = xmlHttp.responseText;
        //AREA OF PROBLEM BELOW
        <?php
            if($_SESSION['alternativeRD']=='true'){              ///YOU ARE HERE, alternativeRD is acting stupid 
        ?>
            document.getElementById("serverInputList").innerHTML = return_data;
        <?php 
            }else{
        ?>
            document.getElementById("serverInputFSIF").innerHTML = return_data;
        <?php 
        }
        ?>

    }
}

// Send the data to PHP now... and wait for response to update the status div
xmlHttp.send(vars); // Actually executes the request
document.getElementById("serverInputFSIF").innerHTML = "processing...";

}

Answer 1

Your Javascript was printed only once, before you use AJAX. You can return the session value together with response, or you can set the cookie in PHP, than use it in javascript.