如何使用Django从用户资料预填充表单字段

# profiles/models.py
from django.db import models
from django.contrib.auth.models import User
from django_countries.fields import CountryField

class UserProfile(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE)
    default_full_name = models.CharField(max_length=50, null=True, blank=True)
    default_phone_number = models.CharField(max_length=20, null=True, blank=True)
    default_country = CountryField(blank_label='Country', null=True, blank=True)
    # ... 其他资料字段

    def __str__(self):
        return self.user.username

# reviews/models.py
from django.db import models
from django.core.validators import MinValueValidator, MaxValueValidator
from profiles.models import UserProfile # 导入UserProfile模型

class Reviews(models.Model):
    class Meta:
        verbose_name_plural = "Reviews"

    review_title = models.CharField(max_length=120)
    name = models.CharField(max_length=200) # 需要预填充的字段
    updated_on = models.DateTimeField(auto_now=True)
    review_text = models.TextField(null=True, max_length=500)
    review_rating = models.IntegerField(validators=[
        MinValueValidator(1),
        MaxValueValidator(5)], null=True)
    image = models.ImageField(upload_to="reviews_images/", null=True, blank=True)
    approved = models.BooleanField(default=False)
    user_profile = models.ForeignKey(UserProfile, on_delete=models.SET_NULL,
                                     null=True, blank=True, related_name='review_profile')

    def __str__(self):
        return self.name

# reviews/forms.py
from django import forms
from .models import Reviews
# from .widgets import CustomClearableFileInput # 假设有自定义文件输入组件

class ReviewsForm(forms.ModelForm):
    """ Creates the reviews form """

    class Meta:
        model = Reviews
        fields = ("name", "review_title", "review_rating", "review_text", "image")

    # 如果有自定义文件输入，可以保留
    # image = forms.ImageField(
    #     label='Image', required=False, widget=CustomClearableFileInput
    # )

# reviews/views.py
from django.shortcuts import render, redirect, reverse
from django.contrib import messages
from django.contrib.auth.decorators import login_required
from .forms import ReviewsForm
from profiles.models import UserProfile # 导入UserProfile模型

@login_required
def add_review(request):
    """
    允许登录用户添加评论，并预填充其全名。
    """
    # 1. 获取当前用户的UserProfile实例
    # 确保在处理GET和POST请求之前都能获取到profile，
    # 这样在GET请求时才能用于initial，在POST请求时才能关联review
    profile = None
    if request.user.is_authenticated:
        try:
            profile = UserProfile.objects.get(user=request.user)
        except UserProfile.DoesNotExist:
            # 如果用户没有UserProfile，可以在这里处理，例如创建默认资料或显示错误
            messages.warning(request, "您的个人资料不完整，请先完善。")
            # 也可以选择重定向到资料编辑页面
            # return redirect(reverse('profile'))

    if request.method == 'POST':
        # 2. 处理POST请求：表单直接使用提交的数据
        form = ReviewsForm(request.POST, request.FILES)
        if form.is_valid():
            # 3. 保存表单数据，并关联UserProfile
            review = form.save(commit=False) # 暂时不保存到数据库
            if profile:
                review.user_profile = profile
                # 如果用户在表单中修改了name，这里可以选择是否强制使用profile中的name
                # review.name = profile.default_full_name # 强制使用profile的name
            review.save() # 最终保存
            messages.success(request, '评论已成功发布，等待审核。')
            return redirect(reverse('reviews'))
        else:
            messages.error(request, '添加评论失败。请确保表单内容有效。')
    else:
        # 4. 处理GET请求：使用initial参数预填充表单
        initial_data = {}
        if profile:
            initial_data['name'] = profile.default_full_name
        form = ReviewsForm(initial=initial_data)

    template = 'reviews/add_review.html'
    context = {
        'form': form,
    }
    return render(request, template, context)

<!-- reviews/add_review.html -->
{% extends "base.html" %}
{% block content %}
    <div class="container">
        <h2>添加评论</h2>
        <form method="POST" action="{% url 'add_review' %}" enctype="multipart/form-data">
            {% csrf_token %}
            {{ form.as_p }} {# 或者使用更精细的表单渲染方式 #}
            <button type="submit" class="btn btn-primary">提交评论</button>
        </form>
    </div>
{% endblock %}