如何在 Python/flask 中读取 HTML 复选框的状态

Question

I've built a working web page and python/flask program but cannot figure out how to read the state of a webpage checkbox in the python code. I've figured out how to set a checkbox from python, just not how to read it. Here is the html for one of the checkboxes:

<div class="slideThree">    
    <input type="checkbox" value="None" id="chk_01" name="chk_01" {{chk_01_checked}}/>
    <label for="chk_01"></label>
</div>

The html code is in a separate file from the python program. It looks like I need to use some combination of 'request' or 'get' instructions but cannot find clear examples on how to do it. I'm a novice in both python and html, so any help appreciated.

Answer 1

The checkbox exists in the browser, the python code runs on the server. Basically the server will have no knowlegde of the checkbox state. If you want to change that, you need to connect the two.

Two options there:

(1): the checkbox is included in a form and the state is included in the form data when the user clicks submit.

(2): you assign an event handler to the state of the checkbox. On the event handler, you post the new state to some AJAX resource. In Flask you add a route for the AJAX URL and receive the state changes.

Answer 2

Here is what I am trying to do. I added a action (form action) line in html, then a function in python to process it. But the python function never executes so I clearly don't have something right.

here is the html:

<td style="width:auto">
<form action="ManToggle">
<div class="slideThree">
    <input type="checkbox" value="None" id="chk_01_Man" name="chk_01_Man" />
    <label for="chk_01_Man"></label>
</div>
</form>
</td> 

Here is the python:

@app.route('/ManToggle', methods=['GET'])
def ManToggleUpdate():
    print ("function executes")
    test = request.form['chk_01_Man']
    if test == True :
        # do something
    else :
        # do something else