首页 > 解决方案 > 在 Python/Flask 中访问 HTML 表单数据

问题描述

我正在与一个使用 Flask 的项目的合作伙伴合作,该项目需要将一个(变量)JSON 对象从 HTML 文件传递​​到 app.py 文件,从而查询我们的数据库。我的伙伴使用文本输入字段成功地编写了一个版本,将检索到的记录打印到控制台。然而,我们在实现下拉菜单时已经改变了很多东西,我们无法让事情再次正常工作。

就目前而言,我能够 ping app.py 文件并返回一个虚拟响应(例如,将“hello”打印到控制台),但我似乎无法访问通过 JSON 对象传入的实际数据. (我什至还没有弄乱数据库——只是试图操纵对象。)最近,我得到一个 GET (url) 500 (INTERNAL SERVER ERROR),当我使用 POST 方法时也是如此。

我已经阅读了很多关于类似问题的讨论(这里这里这里,仅举几例),并尝试了几种不同的方法。我想我一定是在表格上做错了,而且解决方案似乎应该相当简单,但我没有太多运气弄清楚它。

以下是相关的 HTML 和 JavaScript:

<!-- establish the Flask form which will send the selected airports to the Python code and database -->
<form name="selected_route" id="selected_route" method="GET">

    <p>Departure</p>
    <p>
        <!-- dropdown menu for departure state -->
        <select name="departure_state" id="departure_state" onChange="changeDepAirport(this.value);">
        </select>

        <!-- dropdown menu for departure airport, generated by choice of state -->
        <select name="departure_airport" id="departure_airport">
        <option value="" disabled selected>Select an airport</option>
        </select>
    </p>

    <p>Arrival</p>
    <p>
        <!-- dropdown menu for arrival state -->
        <select name="arrival_state" id="arrival_state" onChange="changeArrivAirport(this.value);">
        </select>

        <!-- dropdown menu for arrival airport, generated by choice of state -->
        <select name="arrival_airport" id="arrival_airport">
        <option value="" disabled selected>Select an airport</option>
        </select>
    </p>

    <!-- submit button for the departure and arrival parameters, which will visualize the data for that route -->
    <p>
        <button name="go" id="go" type="submit" onclick="retrieveRouteData()">Go!</button>
    </p>
</form>

<script>
// function to retrieve the data for the selected route
function retrieveRouteData() {
    departure_airport = document.getElementById("departure_airport").value;
    arrival_airport = document.getElementById("arrival_airport").value;
    route_object = { "departure_airport" : departure_airport,
                        "arrival_airport" : arrival_airport};
    console.log(route_object);

    testAj(function(output){
        console.log("1")
        console.log(output)
    });

    function testAj(handleData) {
        $(document).ready(function() {
            $('form').submit(function (e) {
                var url = "{{ url_for('test') }}"; // send the data here
                $.ajax({
                    type: "GET",
                    url: url,
                    data: route_object,
                    success: function (data) {
                        console.log(data)  // display the returned data in the console.
                    }
                });
                e.preventDefault(); // block the traditional submission of the form.
            });
        });
    };
 };

 generateStateLists(); // calls the function to populate the initial dropdowns

 </script>

这是Python代码:

from flask import Flask, jsonify, render_template, redirect, url_for, g, Response, request
from flask_cors import CORS
from flask_wtf import FlaskForm
from wtforms import StringField
from pymongo import MongoClient
from bson import json_util
from bson.json_util import dumps
import json
import os

app = Flask(__name__)
app.secret_key = ####

@app.route('/')
def home():
    print("come to home")
    return render_template('home.html')

# send json file
@app.route('/send')
def send():
    return "<a href=%s>file</a>" % url_for('static', filename='StateCityCode.json')


@app.route('/test', methods=['GET'])
def test():
    data = request.get_json()
    return data

if __name__ == '__main__':
    app.run(host='0.0.0.0',debug=True)

预先感谢您的帮助!

标签: javascriptpythonjqueryajaxflask

解决方案


在发送和设置调用的 json 标头之前尝试对 json 数据进行字符串化,如下所示:

$.ajax({
                    type: "POST",
                    dataType: "json",
                    url: url,
                    data: JSON.stringify(route_object),
                    contentType: "application/json;charset=utf-8"
                    success: function (data) {
                        console.log(data)  // display the returned data in the console.
                    }
                });

推荐阅读