Question

我按照步骤制作会话变量的一步一步表格。

一步我有一个文件上传预览图像并显示一个上传按钮，按下时按钮调用需要修改$ _SESSION变量的php脚本，以及回显上传文件的路径。

当我在没有require_once('config.php')的调试器中测试它时，它完全按照我的预期工作，显示图像及其文件名，但是，由于某种原因，当我包含配置文件时，我迭代通过它在我的调试器中，它似乎运行PHP脚本两次，它正确更新会话变量，但文件名不再回显，数据在到达前端之前丢失。

我无法判断错误是在config.php文件中，还是在AJAX调用中，还是在我失踪的其他地方。

标记（＆＃39; step4.php＆＃39;）：

<form method="post" action="step5.php">
    <span id="newfile">
        <input type="file" name="uploaded_file" id="imageupload" accept=".jpg, .jpeg, .png">
        <img alt="Preview Loading..." id="imagepreview">
    </span>
    <!-- The submit button is elsewhere before the end of the form, it acts as a next button -->
</form>

javascript函数：

$(document).on('click', '#uploadbutton', function(e) {
    e.preventDefault();
    //Grab upload elements and and file
    var uploadbutton = this;
    var uploader = document.getElementById('imageupload');
    var file = document.getElementById('imageupload').files[0];
    //Hide the upload elements
    uploadbutton.parentNode.removeChild(uploadbutton);
    uploader.parentNode.removeChild(uploader);
    //Make the form and pass it to server
    var formData = new FormData();
    formData.append('file', file); //$_FILES['file']
    $.ajax({
        url: 'uploadfile.php',
        type: 'POST',
        data: formData,
        processData: false,
        contentType: false
    })
    .done(function(data) {//Data is the relative path to the file
        //Hide the old content
        document.getElementById('newfile').innerHTML = '';
        //Show the new image
        var text = document.createTextNode('Uploaded File: '+data.replace('temp/', '', data));
        var br = document.createElement("br");
        var imgElement = document.createElement("IMG");
        imgElement.setAttribute('src', data);
        document.getElementById('newfile').appendChild(text);
        document.getElementById('newfile').appendChild(br);
        document.getElementById('newfile').appendChild(imgElement);
    })
    .fail(function() {
        alert("Error uploading the file. Hit refresh and try again.");
    });
});

＆＃39; uploadfile.php＆＃39; :(我的调试器显示的那个被执行两次......）

<?php
//require_once('config.php'); //THE PROBLEM?

if($_FILES) {
    //Get the uploaded file information
    $name_of_uploaded_file = $_FILES['file']['name'];
    //Actually upload the file to the server!
    $upload_folder = 'temp/'; //Make a file named temp
    $path_of_uploaded_file = $upload_folder.$name_of_uploaded_file;
    $tmp_path = $_FILES["file"]["tmp_name"];

    if(is_uploaded_file($tmp_path)) {
        copy($tmp_path,$path_of_uploaded_file);
        $_SESSION['step4filepath'] = $path_of_uploaded_file;
        echo $path_of_uploaded_file;
    }   
}

?>

＆＃39; config.php＆＃39;：当它被包含时搞砸的东西

<?php
session_start();

//Initialize session data
if(empty($_SESSION)) {
    if(!isset($_SESSION['step4filepath'])) {
        $_SESSION['step4filepath'] = '';
    }
}

//Update session data
if($_SERVER['REQUEST_METHOD'] === 'POST') {

    if($_SESSION['currentPage'] == 4) {
        //input for step 4, we just want filename if they submit the form
        $_SESSION['step4filepath'] = $_POST['step4filepath'];
    }
    //Enable us to hit the back button!
    header("Location: " . $_SERVER['REQUEST_URI']);
}
?>

完全迷失了。

Answer 1

可能是这个？为什么配置文件中存在该行？

header("Location: " . $_SERVER['REQUEST_URI']);

Answer 2

看起来config.php正在用$ _POST ['step4filepath']替换$ _SESSION ['step4filepath']的值，而不是将其保留为$ path_of_uploaded_file。

修改

如其他地方所述，header（）将导致重新加载。我的答案是无关紧要的，因为在设置var之前调用了config.php。

Answer 3

解决方案1

替换

$(document).on('click', '#uploadbutton', function(e) {

到

$(document).off('click').on('click', '#uploadbutton', function(e) {

解决方案2：见下面的示例代码

$(document).on("click", "#someID", function(e) {
    $(this).attr("disabled","disabled");
    // Disabling the input stops the event from firing multiple times.
    var targetObj = $(this);
    // targetObj can be used within the $.POST function, not $(this)
   var myVariable = "Hello world";
   $.post("/DoSomethingAJAXY.php", { variable1: myVariable },
   function(data, status){
    if (status == "success") {
        // Do something
    }
    $(targetObj).removeAttr("disabled");
    // Re-enable the event input trigger
});
}

require_once（）或AJAX导致php脚本运行两次

3 个答案: