如何在点击后更新Django模型的total_points字段值？附代码示例

Is the Desired Feasible with Current Code? #

No, the current setup won’t work to implement the "add/subtract points" functionality. Here’s why:

• Your views.py only handles GET requests—there’s no logic to process form submissions (POST requests) from the template.
• The template uses form fields ({{ form.name }} etc.) but your view doesn’t pass a form instance to the context, so those fields won’t render properly.
• The points_filter line has a bug: total_points is an IntegerField, but you’re filtering with total_points=True (which will only match entries where total_points=1, probably not what you intended).
• There’s no code to adjust total_points based on the submitted pluspoints/minuspoints values.

Alternative Implementation Solutions #

Solution 1: Server-Side Form Submission (Basic Approach)

This fixes the current code to handle form submissions and update points on the server.

1. Create a ModelForm (add forms.py to your app):

from django import forms
from .models import test

class TestPointsForm(forms.ModelForm):
    class Meta:
        model = test
        fields = ['name', 'pluspoints', 'minuspoints']

2. Update the View to handle GET/POST and update points:

from django.shortcuts import render, redirect
from .models import test
from .forms import TestPointsForm

def points(request):
    # Fix the filter example: show entries with positive points
    points_filter = test.objects.filter(total_points__gt=0)
    points_count = test.objects.count()

    if request.method == 'POST':
        form = TestPointsForm(request.POST)
        if form.is_valid():
            name = form.cleaned_data['name']
            add_points = form.cleaned_data['pluspoints']
            subtract_points = form.cleaned_data['minuspoints']

            # Get or create a record for the given name
            point_record, created = test.objects.get_or_create(name=name)
            
            # Adjust total points
            if add_points:
                point_record.total_points += 1
            if subtract_points:
                point_record.total_points -= 1
            point_record.save()

            return redirect('points') # Prevent duplicate submissions
    else:
        form = TestPointsForm()

    context = {
        'form': form,
        'points_filter': points_filter,
        'points_count': points_count,
    }
    return render(request, 'point/points.html', context)

3. Optional: Make Plus/Minus Mutually Exclusive
   If you don’t want users to select both options (which would cancel out), replace the two checkboxes with radio buttons in your form:

class TestPointsForm(forms.ModelForm):
    POINT_ACTION_CHOICES = [
        ('plus', 'Add 1 Point'),
        ('minus', 'Subtract 1 Point'),
    ]
    point_action = forms.ChoiceField(choices=POINT_ACTION_CHOICES, widget=forms.RadioSelect)
    
    class Meta:
        model = test
        fields = ['name', 'point_action']

Then update your template to use {{ form.point_action|as_crispy_field }} instead of the two checkbox fields.

Solution 2: AJAX for Seamless Updates (No Page Reload)

For a better user experience, use AJAX to update points without reloading the page.

1. Add an AJAX Handler View to views.py:

from django.http import JsonResponse
from .models import test

def update_points(request):
    if request.method == 'POST':
        name = request.POST.get('name')
        action = request.POST.get('action') # 'plus' or 'minus'
        
        point_record, created = test.objects.get_or_create(name=name)
        
        if action == 'plus':
            point_record.total_points += 1
        elif action == 'minus':
            point_record.total_points -= 1
        point_record.save()
        
        return JsonResponse({'success': True, 'new_total': point_record.total_points})
    return JsonResponse({'success': False})

2. Add a URL Pattern for the AJAX view in urls.py:

from django.urls import path
from . import views

urlpatterns = [
    path('points/', views.points, name='points'),
    path('update-points/', views.update_points, name='update_points'),
]

3. Modify the Template to use buttons and AJAX:

<div id="points_container">
 {% csrf_token %}
 <div class="row">
 <div class="col-3">
 <input type="text" id="name_input" placeholder="Enter name" required>
 </div>
 <div class="col-3">
 <button type="button" class="btn btn-success" id="plus_btn">Add 1 Point</button>
 </div>
 <div class="col-3">
 <button type="button" class="btn btn-danger" id="minus_btn">Subtract 1 Point</button>
 </div>
 </div>
 <div id="update_result" class="mt-2"></div>
</div>

<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
<script>
$(document).ready(function() {
    function sendPointUpdate(action) {
        const name = $('#name_input').val();
        if (!name) {
            $('#update_result').text('Please enter a name first!');
            return;
        }

        $.ajax({
            url: "{% url 'update_points' %}",
            type: "POST",
            data: {
                'name': name,
                'action': action,
                'csrfmiddlewaretoken': $('input[name=csrfmiddlewaretoken]').val()
            },
            success: function(response) {
                if (response.success) {
                    $('#update_result').text(`Updated total: ${response.new_total}`);
                } else {
                    $('#update_result').text('Failed to update points.');
                }
            },
            error: function() {
                $('#update_result').text('Something went wrong.');
            }
        });
    }

    $('#plus_btn').click(() => sendPointUpdate('plus'));
    $('#minus_btn').click(() => sendPointUpdate('minus'));
});
</script>

Quick Best Practices Note #

• Follow Django conventions: Rename your model from test to Test (PascalCase) for clarity.
• Use more descriptive model names like UserPointRecord instead of test to avoid confusion.

内容的提问来源于stack exchange，提问作者Yuksel Bastan