使用AJAX传递数组

Question

I am used to writing AJAX using the following structure, where I would end up sending variables to PHP

function requestToggle(type, user, elem) {
                    _(elem).innerHTML = 'please wait ...';
                    var ajax = ajaxObj("POST", "request_system.php");
                    ajax.onreadystatechange = function () {
                        if (ajaxReturn(ajax) == true) {
                            if (ajax.responseText == "request_sent") {
                                _(elem).innerHTML = 'OK Request Sent';
                            } else if (ajax.responseText == "unrequest_ok") {
                                _(elem).innerHTML = '<button onclick="requestToggle(\'request\',\'<?php echo $u; ?>\',\'requestBtn\')">Request Number</button>';
                            } else {
                                alert(ajax.responseText);
                                _(elem).innerHTML = 'Try again later';
                            }
                        }
                    }
                    ajax.send("type=" + type + "&user=" + user);
                }

The example that I want to work on is for a photo upload form and the PHP script is using the $_FILES array but I am unsure how I would go about passing this array to the PHP using AJAX.

Here is the PHP

<?php 
$result = "";
if (isset($_FILES["avatar"]["name"]) && $_FILES["avatar"]["tmp_name"] != ""){
    $fileName = $_FILES["avatar"]["name"];
    $fileTmpLoc = $_FILES["avatar"]["tmp_name"];
    $fileType = $_FILES["avatar"]["type"];
    $fileSize = $_FILES["avatar"]["size"];
    $fileErrorMsg = $_FILES["avatar"]["error"];
    $kaboom = explode(".", $fileName);
    $fileExt = end($kaboom);
    list($width, $height) = getimagesize($fileTmpLoc);
    if($width < 10 || $height < 10){
        $result = "That image has no dimensions";
        echo $result;
        exit();
    }
    $db_file_name = rand(100000000000,999999999999).".".$fileExt;
    if($fileSize > 1048576) {
        $result = "Your image file was larger than 1mb";
        echo $result;
        exit();
    } else if (!preg_match("/\.(gif|jpg|png)$/i", $fileName) ) {
        $result = "Please only JPG, GIF or PNG images";
        echo $result;
        exit();
    } else if ($fileErrorMsg == 1) {
        $result = "An unknown error occurred";
        echo $result;
        exit();
    }
    $sql = "SELECT profilePicture FROM User WHERE username='$log_username' LIMIT 1";
    $query = mysqli_query($db_conx, $sql);
    $row = mysqli_fetch_row($query);
    $avatar = $row[0];

        //delete old pic if set
    if($avatar != ""){
        $picurl = "users/$log_username/$avatar"; 
        if (file_exists($picurl)) { unlink($picurl); }
    }
        //move file from temp folder to users folder
    $moveResult = move_uploaded_file($fileTmpLoc, "users/$log_username/$db_file_name");
    if ($moveResult != true) {
        $result = "File upload failed";
        echo $result;
        exit();
    }
    include_once("image_resize.php");
        //replace original file with resized version
    $target_file = "users/$log_username/$db_file_name";
    $resized_file = "users/$log_username/$db_file_name";
    $wmax = 400;
    $hmax = 600;
    img_resize($target_file, $resized_file, $wmax, $hmax, $fileExt);
    $sql = "UPDATE User SET profilePicture='$db_file_name' WHERE username='$log_username' LIMIT 1";
    $query = mysqli_query($db_conx, $sql);
    mysqli_close($db_conx);
    //header("location: user.php?u=$log_username");
       $result = "upload_success";
        echo $result;

    exit();
}
?>

UPLOAD FORM

$avatar_form = '<div class="bhoechie-tab-content" id="uploadphoto">';
        $avatar_form .= '<center>';
        $avatar_form .= '<form id="avatar_form"" method="post" enctype="multipart/form-data">';
        $avatar_form .= '<h1>Change avatar</h1>';
        $avatar_form .= '<input type="file" name="avatar" required>';
        $avatar_form .= '<p><input type="submit" value="Upload"></p>';
        $avatar_form .= '<p id="status"></p>';
        $avatar_form .= '</form>';
        $avatar_form .= '</center></div>';

Answer 1

You can easily enough pass an array eg ajax.send("type=" + type + "&user=" + user + "&files=" + files);

Having not seen the rest of your code I can't provide a full answer, but I'm assuming you're somehow creating a files array in js and want to pass that to the php? If so, the variable 'files' would then be using in PHP like:

$files= $_REQUEST['files'];