POST 方法在被请求时不断发送 400 错误

Question

我目前一直在使用 Flask 和 MongoDB 来试验一个小型应用程序。我目前正在让用户获取 MongoDB 集合中的所有法则，并通过将 JSON 发送到服务器，通过 POST 方法为 MongoDB 集合创建新法则。但是，下面的输出显示向 /post/law 发送 POST 请求将发出 400 错误。127.0.0.1 - - [12/Aug/2020 09:21:50] "GET / HTTP/1.1" 200 -127.0.0.1 - - [12/Aug/2020 09:21:50] "GET /laws HTTP/1.1" 200 -127.0.0.1 - - [12/Aug/2020 09:21:54] "POST /post/law HTTP/1.1" 400 -我对为什么会发生此错误感到有些困惑。我知道 400 错误通常与错误请求有关，但是，我不确定错误请求错误发生在哪里？# This handles the POST [e-mail]('/post/law', methods = ["POST"])def post_law():    if request.is_json:        content = request.get_json()        print(content)客户端：<!--This tries to send a request to /post/law--><h1>Submit a Law</h1><form action="", method="GET">    <div id="law_name_section">        <label>Name of the law:</label>        <input type="text" required id="law_name">    </div>    <div id="law_description_section">        <label>Description of the law:</label>        <input type="text" required id="law_description">    </div>    <div id="law_url_section">        <label>URL to the law:</label>        <input type="text" required id="law_url">    </div>    <input type="submit" value="Submit law" onclick="submitLaw()"></form><script>// submitLaw() tries to send a request to /post/law in a JSON request    async function submitLaw() {        let name = await document.getElementById('law_name').value         let description = await document.getElementById('law_description').value         let url = await document.getElementById('law_url').value        let options = {            method: "POST",            headers: { "Content-Type": "application/json" },            body: {                name: name,                description: description,                url: url,                status: "Bill"            }        }        let response = await fetch("http://127.0.01:8000/post/law", options)        if (response.ok) {            alert("Successfully sent data to /post/law")        } else {            alert(`Couldn't send data to /post/law`)        }    }</script>

Answer 1

可能是因为您的视图没有返回响应。尝试：

@app.route('/post/law', methods = ["POST"])

def post_law():

    if request.is_json:

        content = request.get_json()

        print(content)

    return "hello"

另外，您的网址格式不正确。应该：

 await fetch("http://127.0.0.1:8000/post/law", options)

而且，为什么所有的async电话？唯一应该异步的是你的fetch()

您也有 2 个submits发生。尝试这个：

<!--This tries to send a request to /post/law-->

<h1>Submit a Law</h1>

<form action="", method="POST">

    <div id="law_name_section">

        <label>Name of the law:</label>

        <input type="text" required id="law_name">

    </div>

    <div id="law_description_section">

        <label>Description of the law:</label>

        <input type="text" required id="law_description">

    </div>

    <div id="law_url_section">

        <label>URL to the law:</label>

        <input type="text" required id="law_url">

    </div>

    <input type="button" value="Submit law" onclick="submitLaw();">

</form>

<script>

// submitLaw() tries to send a request to /post/law in a JSON request

    function submitLaw() {

        let name = document.getElementById('law_name').value;

        let description = document.getElementById('law_description').value; 

        let url = document.getElementById('law_url').value;

        let options = {

            method: "POST",

            headers: { "Content-Type": "application/json" },

            body: {

                name: name,

                description: description,

                url: url,

                status: "Bill"

            }

        }

        let response = await fetch("http://127.0.0.1:8000/post/law", options)

        if (response.ok) {

            alert("Successfully sent data to /post/law")

        } else {

            alert(`Couldn't send data to /post/law`)

        }

    }

</script>