使用烧瓶开机自检后使选定选项保持选中状态 [英] Having a select option stay selected after POST with Flask

问题描述

我正在尝试使用Flask获取在页面刷新后选择保留的选择选项。我曾尝试使用JAG2执行此操作，但不起作用：

<div class="col-sm-4 col-lg-4 col-md-4">
    <select class="form-control" id="myselect" name="thing" required>
        <option value="" {% if thing=='' %} selected {% endif %} ></option>
        <option value="Foo" name="Foo" id="Foo" {% if thing =="Foo" %} selected {% endif %}>Foo</option>
        <option value="Bar" name="Bar" id="Bar" {% if thing =="Bar" %} selected {% endif %}>Bar</option>
    </select>
</div>

其中使用Python填充并传递变量energy。在研究了这一点之后，我觉得这是在Flask中实现这一点的方法，尽管显然不是这样。如有任何帮助，我们将不胜感激！

@app,route('/things', methods=['POST']
def things()
    if len(facts['thing']) > 11:
        energy = [facts['thing'][0:8],facts['thing'][9:]]
    else:
        energy = [facts['things']]
    ...
    return render_template('thing.html', thing=energy)

推荐答案

请参阅此示例，因为它适用于您尝试执行的操作。我无法准确调试您的代码中出了什么问题，因为您已经向我提供了部件，而我不知道它们在做什么。

文件夹结构

Test
|___templates
|   |___things.html
|___Test.py

things.html

<form method="post">
    <div class="col-sm-4 col-lg-4 col-md-4">
        <select title="thing" class="form-control" id="myselect" name="thing" required>
            <option value="" {% if thing=='' %} selected {% endif %} ></option>
            <option value="Foo" name="Foo" id="Foo" {% if thing =="Foo" %} selected {% endif %} >Foo</option>
            <option value="Bar" name="Bar" id="Bar" {% if thing =='Bar' %} selected {% endif %}>Bar</option>
        </select>
        <button type="submit">SEND</button>
    </div>
</form>

Test.py

from flask import Flask, render_template, request

app = Flask(__name__)
PORT = 5000


@app.route('/things', methods=['GET', 'POST'])
def things():
    """
    Accepts both GET and POST requests. If it's a GET request,
    you wouldn't have a last selected thing, so it's set to an
    empty string. If it's a POST request, we fetch the selected
    thing and return the same template with the pre-selected
    thing.
    You can improve on this and save the last selected thing
    into the session data and attempt to retrieve it from there.
    """
    thing = ''
    if request.method == 'GET':
        return render_template('things.html', thing=thing)
    else:
        thing = request.form.get('thing', '')
        return render_template('things.html', thing=thing)


if __name__ == '__main__':
    app.run(port=PORT)

这篇关于使用烧瓶开机自检后使选定选项保持选中状态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！