英文:
How can I pass JSON data through serialization and then parse them using external Brython script?
问题
附加的Flask + Brython源代码应该在浏览器屏幕上打印20个随机数字（介于-100和100之间）。
然而，它没有。
Brython脚本无法解析JSON数据。
我该如何解决这个问题？
英文:
The attached Flask+Brython source code was supposed to print 20 random numbers (between -100 and 100) on the browser screen.
However, it doesn't.
The Brython script is failing to parse JSON data.
How can I fix this?
app.py
from flask import Flask, render_template
from flask import request, redirect
from flask_socketio import SocketIO, emit
async_mode = None
app = Flask(__name__)
socketio_obj = SocketIO(app)
@app.route('/', methods=['GET', 'POST'])
def index():
import random
import json
random_list = []
for i in range(0, 20):
n = random.randint(-100, 100)
random_list.append(n)
json_data = str(json.dumps(random_list))
return render_template('index.html', json_data=json_data)
if __name__ == '__main__':
socketio_obj.run(app, debug=True)
index.html
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Brython Test</title>
<script src="../static/brython/Brython-3.11.1/brython.js"></script>
<script src="../static/brython/Brython-3.11.1/brython_stdlib.js"></script>
</head>
<body onload="brython()">
<script type="text/python" src="../static/brython/index.py"></script>
</body>
</html>
index.py
from browser import document, window, console
import os
random_list = "{{json_data}}"
document <= random_list
答案1
得分: 1
很抱歉，只能在模板中使用jinja语法，而不能在加载的文件中使用。所以，你只能将brython代码集成到你的模板中，或者通过ajax从另一个端点获取数据。
要将变量传递给brython，你可以使用jinja过滤器tojson，因为它的语法类似。这将为你提供数字列表，然后你可以将它们附加到文档中。
Flask (./app.py)
@app.route('/')
def index():
random_list = [random.randint(-100, 100) for _ in range(20)]
return render_template('index.html', **locals())
Brython (./index.html)
from browser import document
random_list = {{ random_list | tojson }}
document <= ','.join(str(item) for item in random_list)
如果你想通过Ajax获取数据，可以使用以下变体。
Flask (./app.py)
from flask import jsonify
import random
@app.route('/')
def index():
return render_template('index.html')
@app.route('/data')
def data():
random_list = [random.randint(-100, 100) for _ in range(20)]
return jsonify(random_list)
Brython (./static/brython/index.py)
from browser import ajax, document
read = lambda req: document <= ','.join(str(n) for n in req.json)
ajax.get("/data", mode="json", oncomplete=read)
英文:
Unfortunately you can only use the jinja syntax within a template and not in a loaded file. So you have nothing else to do than integrate the brython code into your template or obtain the data from another endpoint via ajax.
To pass a variable to brython, you can use the jinja filter tojson due to the similarity in syntax. This gives you the list of numbers and you can attach them to the document.
Flask (./app.py)
@app.route('/')
def index():
random_list = [random.randint(-100, 100) for _ in range(20)]
return render_template('index.html', **locals())
Brython (./index.html)
from browser import document
random_list = {{ random_list | tojson }}
document <= ','.join(str(item) for item in random_list)
If you want to get the data via Ajax, the following variant is possible.
Flask (./app.py)
from flask import jsonify
import random
@app.route('/')
def index():
return render_template('index.html')
@app.route('/data')
def data():
random_list = [random.randint(-100, 100) for _ in range(20)]
return jsonify(random_list)
Brython (./static/brython/index.py)
from browser import ajax, document
read = lambda req: document <= ','.join(str(n) for n in req.json)
ajax.get("/data", mode="json", oncomplete=read)
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