PHP发回空身 [英] PHP sends back empty body

问题描述

我正在尝试将表单数据从Vue Resource发送到我的PHP页面。我可以看到它显示在PHP页面上，但是当我以JSON的形式发回它时，我得到一个空响应。为什么发送空响应？

I'm trying to send form data from Vue Resource to my PHP page. I can see it displayed on the PHP page but when I send it back as JSON I get an empty response. Why is it sending an empty response?

看起来问题是问题是提交按钮未在PHP中设置。我不确定为什么会这样。尝试使用 $ _ REQUEST 和 axios / $。发布，但没有区别。

It looks like the problem is that the value for the submit button is not set in PHP. I am not sure why that is happening. Tried using $_REQUEST and axios/$.post but it makes no difference.

if(isset($_POST['submit']){
   echo json_encode($_POST);
}

JS：

JS:

this.$http.post('addalbum.php', new FormData($('#submitalbum')))
.then(data => console.log(data));

HTML：

HTML:

<form class="col s12" id="submitalbum" method="post" action="addalbum.php">
    <div class="row">
        <div class="input-field col s6">
            <input  name="artist" placeholder="Artist" type="text">

        </div>
        <div class="input-field col s6">
            <input  name="title" placeholder="Title" type="text">

        </div>
    </div>
    <div class="row">
        <div class="input-field col s12">
            <input  name="genre" placeholder="Genre">

        </div>
    </div>
    <div class="row">
        <div class="input-field col s12">
            <input  id="released" type="number" name="released" placeholder="Year Released">
        </div>
        <button @click.prevent="addNewAlbum" name="submit" class="waves-effect waves-light btn">Submit</button>
    </div>
</form>

推荐答案

由于多种原因，返回空响应。请参阅下面的解释。

The empty response is returned for multiple reasons. See them explained below.

看来用于查找表单的选择器使用jQuery id selector：

It appears that the selector for finding the form uses the jQuery id selector:

this.$http.post('addalbum.php', new FormData($('#submitalbum')))

但 jQuery函数（即 $（））返回集合（数组）：

But the jQuery function (i.e. $()) returns a collection (an array):

var submitAlbumCollection = $('#submitalbum');
console.log('submitAlbumCollection: ', submitAlbumCollection);

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form class="col s12" id="submitalbum" method="post" action="addalbum.php"></form>

然而 FormData（）需要 HTML < form> 元素 ¹ ，不是数组。

However FormData() needs "An HTML <form> element"¹, not an array.

因此，如果您打算使用jQuery函数，请从中获取第一个元素以获取对表单的引用：

So if you are going to use the jQuery function, take the first element from it to get the reference to the form:

var forms = $('#submitalbum');
if (forms.length) {
    this.$http.post('addalbum.php', new FormData(forms[0]))

按钮元素不发送值

A < button> 不是表单输入，因此表单数据中没有相应的值。如果您想检查表单值，请尝试检查艺术家，标题等。

button elements don't send value

A <button> is not a form input and hence there would not be a corresponding value in the form data. This if you want to check for form values, try checking for the artist, title, etc.

if(isset($_POST['artist'])) {
    echo json_encode($_POST);
}

如果你真的想检查 $ _ POST [ 'submit'] 是真的，你可以：

If you really wanted to check if $_POST['submit'] is truthy, you could:

• 添加一个隐藏的输入：

• add a hidden input:

<input type="hidden" name="submit" value="1">

将按钮转换为提交按钮

convert the button to a submit button

<input type="submit" name="submit" value="1">

从此答案并手动附加表单数据的条目

take the suggestion from this answer and manually append an entry to the form data

在这个phpfiddle 。请注意，phpfiddle不允许多个页面，因此来自 addalbum.php 的代码放在顶部，对它的引用被替换为<？php echo $ _SERVER [ 'PHP_SELF'];？> （即在客户端代码中）。

See a demonstration in this phpfiddle. Note that phpfiddle doesn't allow multiple pages so the code from addalbum.php was placed at the top, and references to it were replaced with <?php echo $_SERVER['PHP_SELF'];?> (i.e. in the client-side code).

此外，PHP代码的第一行有一个缺少的括号：

Additionally, there is a missing parenthesis on the first line of the PHP code:

if(isset($_POST['submit']){

要纠正此问题，请添加缺少的右括号以关闭表达式：

To correct this, add the missing closing parenthesis to close the expression:

if(isset($_POST['submit'])){

---

¹ _{https://developer.mozilla.org/en-US/docs/Web/API/FormData/ FormData}

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