在Wagtail CustomUser模型中为M2M字段实现自动补全功能

问题背景 #

我在Wagtail项目的CustomUser模型中新增了两个多对多字段，当前表单里这两个字段是普通多选框，希望改成自动补全（Autocomplete）形式。现有代码如下：

models.py #

from django.contrib.auth.models import AbstractUser
from django.db import models
from django.utils.translation import gettext_lazy as _

class User(AbstractUser):
    journal = models.ManyToManyField("journal.Journal", verbose_name=_("Journal"), blank=True)
    collection = models.ManyToManyField("collection.Collection", verbose_name=_("Collection"), blank=True)

forms.py #

from django.contrib.auth.forms import UserEditForm, UserCreationForm
from django import forms
from django.utils.translation import gettext_lazy as _
from journal.models import Journal
from collection.models import Collection

class CustomUserEditForm(UserEditForm):
    journal = forms.ModelMultipleChoiceField(queryset=Journal.objects.all(), required=False, label=_("Journal"))
    collection = forms.ModelMultipleChoiceField(queryset=Collection.objects.filter(is_active=True), required=True, label=_("Collection"))

class CustomUserCreationForm(UserCreationForm):
    journal = forms.ModelMultipleChoiceField(queryset=Journal.objects.all(), required=False, label=_("Journal"))
    collection = forms.ModelMultipleChoiceField(queryset=Collection.objects.filter(is_active=True), required=True, label=_("Collection"))

实现步骤 #

1. 导入Wagtail自动补全组件 #

Wagtail Admin内置了适配多对多字段的自动补全组件，先在forms.py中导入所需类：

from wagtail.admin.forms.fields import AutocompleteMultipleChoiceField
from wagtail.admin.widgets import AutocompleteMultipleChoiceWidget

2. 替换表单字段类型 #

将原有的ModelMultipleChoiceField替换为Wagtail的AutocompleteMultipleChoiceField，并绑定对应的自动补全组件：

class CustomUserEditForm(UserEditForm):
    journal = AutocompleteMultipleChoiceField(
        queryset=Journal.objects.all(),
        required=False,
        label=_("Journal"),
        widget=AutocompleteMultipleChoiceWidget(model=Journal)
    )
    collection = AutocompleteMultipleChoiceField(
        queryset=Collection.objects.filter(is_active=True),
        required=True,
        label=_("Collection"),
        widget=AutocompleteMultipleChoiceWidget(model=Collection)
    )

class CustomUserCreationForm(UserCreationForm):
    journal = AutocompleteMultipleChoiceField(
        queryset=Journal.objects.all(),
        required=False,
        label=_("Journal"),
        widget=AutocompleteMultipleChoiceWidget(model=Journal)
    )
    collection = AutocompleteMultipleChoiceField(
        queryset=Collection.objects.filter(is_active=True),
        required=True,
        label=_("Collection"),
        widget=AutocompleteMultipleChoiceWidget(model=Collection)
    )

3. 配置关联模型的搜索字段 #

自动补全需要明确搜索匹配的字段，在Journal和Collection模型中添加search_fields配置：

# journal/models.py
class Journal(models.Model):
    name = models.CharField(_("名称"), max_length=255)
    # 其他模型字段...

    class Meta:
        verbose_name = _("期刊")
        verbose_name_plural = _("期刊")

    def __str__(self):
        return self.name

    # 定义自动补全的搜索字段
    search_fields = [
        models.SearchField('name'),
        # 可添加其他需要搜索的字段，比如描述字段等
    ]

# collection/models.py
class Collection(models.Model):
    name = models.CharField(_("名称"), max_length=255)
    is_active = models.BooleanField(_("是否激活"), default=True)
    # 其他模型字段...

    class Meta:
        verbose_name = _("合集")
        verbose_name_plural = _("合集")

    def __str__(self):
        return self.name

    search_fields = [
        models.SearchField('name'),
    ]

4. 配置Wagtail加载自定义表单 #

在项目settings.py中添加以下配置，让Wagtail的用户管理界面使用你的自定义表单和字段：

WAGTAIL_USER_EDIT_FORM = 'your_app_name.forms.CustomUserEditForm'
WAGTAIL_USER_CREATION_FORM = 'your_app_name.forms.CustomUserCreationForm'
WAGTAIL_USER_CUSTOM_FIELDS = ['journal', 'collection']

注意将your_app_name替换为实际的应用名称。

完成以上步骤后重启项目，用户编辑/创建页面中的journal和collection字段就会变为自动补全选择框，支持输入关键词搜索匹配选项。

内容的提问来源于stack exchange，提问作者xSkolz