无法访问 $_POST 或 $_REQUEST 或 'php://input' - 都不是空的

Question

尝试使用一些变量和长 JSON 发出一个简单的 xhr 请求。当我var_dump($_POST)、var_dump($_REQUEST) 或var_dump(file_get_contents('php://input')) 时，我得到这个：

array(1) {
  ["------WebKitFormBoundarySaVZDjpQjjwsAOHs
Content-Disposition:_form-data;_name"]=>
  string(5725) ""document_id"

608
------WebKitFormBoundarySaVZDjpQjjwsAOHs
Content-Disposition: form-data; name="project_id"

2
------WebKitFormBoundarySaVZDjpQjjwsAOHs
Content-Disposition: form-data; name="user_id"

42
------WebKitFormBoundarySaVZDjpQjjwsAOHs
Content-Disposition: form-data; name="stage"

1
------WebKitFormBoundarySaVZDjpQjjwsAOHs
Content-Disposition: form-data; name="show_save_button"

1
------WebKitFormBoundarySaVZDjpQjjwsAOHs
Content-Disposition: form-data; name="id_user_associatedDoc"

42
------WebKitFormBoundarySaVZDjpQjjwsAOHs
Content-Disposition: form-data; name="annotation"

{"nodes":[{"id":0,"x":67,"y":101,"text":"ng heard. Engaged at village at am equally proceed. Settle nay length almost ham direct extent. Agreement for listening remainder get attention law acuteness","width":229,"height":100,"type":"I","color":"b","scheme":0,"visible":true},{"id":1,"x":325,"y":59,"text":"Entire any had depend and figure winter. Change stairs and men likely wisdom new happen piqued six. Now taken him timed sex world get. Enjoyed married an feeling delight pursuit as offered. As admire roused length likely played pretty to no. Means had joy miles her merry solid order. Entire any had depend and figure winter. Change stairs and men likely wisdom new happen piqued six. Now taken him timed sex world get. Enjoyed married an feeling delight pursuit as offered. As admire roused length likely played pretty to no. Means had joy miles her merry solid order. Entire any had depend and figure winter. Change stairs and men likely wisdom new happen piqued six. Now taken him timed sex world get. Enjoyed married an feeling delight pursuit as offered. As admire roused length likely played pretty to no. Means had joy miles her merry solid order. Entire any had depend and figure winter. Change stairs and men likely wisdom new happen piqued six. Now taken him timed sex world get. Enjoyed married an feeling delight pursuit as offered. As admire roused length likely played pretty to no. Means had joy miles her merry solid order. Entire any had depend and figure winter. Change stairs and men likely wisdom new happen piqued six. Now taken him timed sex world get. Enjoyed married an feeling delight pursuit as offered. As admire roused length likely played pretty to no. Means had joy miles her merry solid order. Entire any had depend and figure winter. Change stairs and men likely wisdom new happen piqued six. Now taken him timed sex world get. Enjoyed married an feeling delight pursuit as offered. As admire roused length likely played pretty to no. Means had joy miles her merry solid order. Entire any had depend and figure winter. Change stairs and men likely wisdom new happen piqued six. Now taken him timed sex world get. Enjoyed married an feeling delight pursuit as offered. As admire roused length likely played pretty to no. Means had joy miles her merry solid order. Entire any had depend and figure winter. Change stairs and men likely wisdom new happen piqued six. Now taken him timed sex world get. Enjoyed married an feeling delight pursuit as offered. As admire roused length likely played pretty to no. Means had joy miles her merry solid order. Entire any had depend and figure winter. Change stairs and men likely wisdom new happen piqued six. Now taken him timed sex world get. Enjoyed married an feeling delight pursuit as offered. As admire roused length likely played pretty to no. Means had joy miles her merry solid order. Entire any had depend and figure winter. Change stairs and men likely wisdom new happen piqued six. Now taken him timed sex world get. Enjoyed married an feeling delight pursuit as offered. As admire roused length likely played pretty to no. Means had joy miles her merry solid order. Entire any had depend and figure winter. Change stairs and men likely wisdom new happen piqued six. Now taken him timed sex world get. Enjoyed married an feeling delight pursuit as offered. As admire roused length likely played pretty to no. Means had joy miles her merry solid order. Entire any had depend and figure winter. Change stairs and men likely wisdom new happen piqued six. Now taken him timed sex world get. Enjoyed married an feeling delight pursuit as offered. As admire roused length likely played pretty to no. Means had joy miles her merry solid order. Entire any had depend and figure winter. Change stairs and men likely wisdom new happen piqued six. Now taken him timed sex world get. Enjoyed married an feeling delight pursuit as offered. As admire roused length likely played pretty to no. Means had joy miles her merry solid order. Entire any had depend and figure winter. Change stairs and men likely wisdom new happen piqued six. Now taken him timed sex world get. Enjoyed married an feeling delight pursuit as offered. As admire roused length likely played pretty to no. Means had joy miles her merry solid order. Entire any had depend and figure winter. Change stairs and men likely wisdom new happen piqued six. Now taken him timed sex world get. Enjoyed married an feeling delight pursuit as offered. As admire roused length likely played pretty to no. Means had joy miles her merry solid order. Entire any had depend and figure winter. Change stairs and men likely wisdom new happen piqued six. Now taken him timed sex world get. Enjoyed married an feeling delight pursuit as offered. As admire roused length likely played pretty to no. Means had joy miles her merry solid order. ","width":200,"height":2420,"type":"I","color":"b","scheme":0,"visible":true}],"edges":[],"metadata":{"documentId":"608","projectId":"2","ranges":[[554,760],[17,302]],"idUserAssociatedDoc":"42"}}
------WebKitFormBoundarySaVZDjpQjjwsAOHs--
"
}

但是一旦我尝试访问这些字段，我就会得到 NULL :(

我尝试了不同的内容类型（multipart/form-data、application/x-www-form-urlencoded 或无）

xhr：

    var xhr = new XMLHttpRequest();
    xhr.open('POST', resultsURL, true);
        xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
    xhr.onload = function () {
        // do something to response
        console.log(this.responseText);
    };

    var dataSave = new FormData();

    dataSave.append('document_id', documentId);
    dataSave.append('project_id', projectId);
    dataSave.append('user_id', userId);
    dataSave.append('stage', stage);
    dataSave.append('show_save_button', showSaveButton);
    dataSave.append('id_user_associatedDoc', idUserAssociatedDoc);
    dataSave.append('annotation', JSON.stringify(json));

    xhr.onreadystatechange = function() {
        switch(xhr.readyState) {
            case XMLHttpRequest.OPENED:
            case XMLHttpRequest.LOADING:
                if(callbackLoading)
                    callbackLoading();
                break;
            case XMLHttpRequest.DONE:

                    console.log("XMLHttpReques.responseText:");
                    console.log(xhr.responseText);


                break;
        }
    }

    xhr.send(dataSave);

关于resultsURL php：

    $docId = $_REQUEST['document_id'];
    echo var_dump($docId); //returns NULL

这不是应该工作吗？你知道我做错了什么吗？

Answer 1

多部分/表单数据

new FromData 是 multipart/form-data 有一个边界 (https://www.w3.org/Protocols/rfc1341/7_2_Multipart.html)。您不应设置任何内容类型标头。 Header 将由浏览器设置。您可以通过$_POST 或$_REQUEST 访问数据。

application/x-www-form-urlencoded

如果你使用 application/x-www-form-urlencoded 你必须发送日期 url 编码。

xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');

// ...

function encodeForm(dataSave) {
  bar r = [];
  dataSave.forEach((v,k) => {
    r.push(encodeURIComponent(k) + '=' + encodeURIComponent(v));
  });
  return r.join('&');
}
xhr.send(encodeForm(dataSave));

您可以使用 $_POST 或 $_REQUEST 访问数据

application/x-www-form-urlencoded 的开销更少。