javascript - PHP $_POST 显示 null，不确定是 HTML、Javascript 还是 PHP

Question

我尝试使用以下代码来填充注释和时间戳的表。不幸的是，当调用 $_POST 时，它似乎总是有一个空值(仅从 php 发布“Error in Post”)。有什么想法吗？

HTML:

     <main>
        <section id="createComment">
            <fieldset>
                <legend><strong>Leave A Comment</strong></legend>
                    <textarea id="commentField" class="text" 
                        name="commentField"></textarea>
                    <button id="submitCComment" onClick="submitComment()" 
                            value="Submit">Submit</button>
            </fieldset>    
        </section>

        <br>

        <table id="commentsTbl">
            <tr>
                <th class="row-datetime">Date Time</th> <th class="row-comment">Comment</th>
            </tr>
        </table>

    </main>

Javascript:

function submitComment() {
    var comment = document.getElementById("commentField").value;
    if (comment == "" || comment == null){
        alert("Comment cannot be blank");
        return false;
    } else {
        var request = new XMLHttpRequest();
        request.onreadystatechange = function() {
            if(request.readyState == 4 && request.status == 200) {
                var text = request.responseText;
                var parser = new DOMParser();
                var parsedXML = parser.parseFromString(text, "text/xml");
                var datetime = parsedXML.getElementsByTagName("datetime")[0].childNodes[0].nodeValue;
                var comment = parsedXML.getElementsByTagName("comment")[0].childNodes[0].nodeValue;
                var table = document.getElementById("commentsTbl");
                var newRow = table.insertRow(1);
                var newCell = newRow.insertCell(0);
                newCell.innerHTML = datetime;
                newCell = newRow.insertCell(1);
                newCell.innerHTML = comment;
            }
        };
        // submit request to the server
        request.open("POST", "/PHP/ProcessCommentDateTime.php", true);
        request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
        request.send("comment=" + comment);
        document.getElementById("commentField").value = "";
    }
}

PHP:

<?php
    $comment;
    $comment = $_POST["commentField"];
    date_default_timezone_set('UTC');
    $datetime = date("Y-m-d H:i:s");
    if($comment == null){
        $comment = "Error on Post";
    }

    //storeComment($comment, $datetime);

    echo('<usercomment>' . 
            '<datetime>' . $datetime . '</datetime>' . 
            '<comment>' . $comment . '</comment>' . 
          '</usercomment>');
?>

Answer 1

您正在发送关键评论并尝试以$comment = $_POST["commentField"];的形式接收

更改为

$comment = $_POST["comment"];

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