Flask变量未显示在HTML中 [英] Flask variables not showing up in HTML
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问题描述
我有一个小烧瓶应用程序，正在使用它来
I have a small flask app I am using it to:
- 制作带有传单地图的HTML页面
- 从HTML页面获取用户输入...
- 使用某些python模块在该输入上运行计算
- 将这些变量返回页面中的JS函数以填充地图
除了 lat 和 lng ，我什么都无法返回到我的HTML {{}}烧瓶变量中.
I cannot get ANYTHING but lat and lng to return into my HTML {{}} flask variables.
这是我的HTML页面:
Here is my HTML page:
<!DOCTYPE html>
<html lang="en">
<html>
<head>
<link rel="stylesheet" href="https://unpkg.com/leaflet@1.3.1/dist/leaflet.css"
integrity="sha512-Rksm5RenBEKSKFjgI3a41vrjkw4EVPlJ3+OiI65vTjIdo9brlAacEuKOiQ5OFh7cOI1bkDwLqdLw3Zg0cRJAAQ=="
crossorigin=""/>
<script src="https://unpkg.com/leaflet@1.3.1/dist/leaflet.js"
integrity="sha512-/Nsx9X4HebavoBvEBuyp3I7od5tA0UzAxs+j83KgC8PU0kgB4XiK4Lfe4y4cgBtaRJQEIFCW+oC506aPT2L1zw=="
crossorigin="">
</script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
</head>
<title>Page Title</title>
<meta charset="utf-8"/>
<style>
#mapid { height: 300px; }
</style>
<body>
<form method="POST">
Latitude to PY: <input name="lat" id="lat"/>
<br/>
Longitude to PY: <input name="lng" id="lng"/>
<br/>
<button>Get data</button>
</form>
{% if lat1 != None and lng1 != None %}
{{lat1}},{{lng1}}
<script>
var lat1 = {{lat1}}
var lng1 = {{lng1}}
</script>
{% endif %}
{% if point != None %}
<p>{{point}}</p>
{% endif %}
{% if GeJ != None %}
{{GeJ}}
<script>
var GeJ = {{GeJ}}
</script>
{% endif %}
<div id="mapid"></div>
<script>
var mymap = L.map('mapid').setView([51.505, -0.09], 13);
L.tileLayer('https://api.tiles.mapbox.com/v4/{id}/{z}/{x}/{y}.png?access_token={accessToken}', {
attribution: 'Map data © <a href="https://www.openstreetmap.org/">OpenStreetMap</a> contributors, <a href="https://creativecommons.org/licenses/by-sa/2.0/">CC-BY-SA</a>, Imagery © <a href="https://www.mapbox.com/">Mapbox</a>',
maxZoom: 18,
id: 'mapbox.high-contrast',
accessToken: 'pk.eyJ1IjoiY2dyb3RoIiwiYSI6ImNqZ2w4bWY5dTFueG0zM2w0dTNkazI1aWEifQ.55SWFVBYzs08EqJHAa3AsQ'
}).addTo(mymap);
function zoomTo() {
mymap.panTo(new L.LatLng(lat1, lng1));
}
function addGJ(){
var myLayer = L.geoJson(GeJ).addTo(mymap);
}
window.onload = zoomTo();
window.onload = addGJ();
</script>
</body>
</html>这是我的Flask Python代码:
Here is my Flask Python code:
from flask import Flask, render_template, request, flash, redirect, url_for,jsonify
from forms import RegistrationForm
import json
import osmnx as ox
import networkx as nx
import matplotlib.pyplot as plt
from networkx.readwrite import json_graph
import pandas as pd
import mplleaflet
app = Flask(__name__)
app.config.update(dict(
SECRET_KEY="powerful secretkey",
WTF_CSRF_SECRET_KEY="a csrf secret key"
))
@app.route('/')
def my_form():
return render_template('map.html')
@app.route('/', methods=['GET', 'POST'])
def my_form_post():
lat = (request.form['lat'])
lng = (request.form['lng'])
lat = lat
lng = lng
point = (lat,lng)
G = ox.core.graph_from_point(point, distance = 500, network_type='walk')
fig, ax = ox.plot_graph(G)
GJ = mplleaflet.fig_to_geojson(fig=ax.figure)
#return lat, ",", lng
return render_template('map.html', lat1=lat, lng1=lng, GeJ=GJ, point="test_string")`
if __name__ == "__main__":
app.run(host='0.0.0.0',port=5000,debug=True)
Flask应用程序运行正常，因此不需要担心文件结构.我只是无法获取任何其他变量来返回我的HTML.我什至尝试制作一些小的字符串虚拟变量，而不是真正的变量.没有骰子.
The Flask app is working fine so the file structure is not a concern. I just cannot get any other variables to return into my HTML. I even tried making little string dummy variables other that the real ones. No Dice.
谢谢
推荐答案
You could try using the builtin none value http://jinja.pocoo.org/docs/templates/#none
然后执行以下操作:
{% if lat1 is not none and lng1 is not none %}
这篇关于Flask变量未显示在HTML中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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