Django返回两个单独的__str__以获取模型表单 [英] Django Return Two Separate __str__ for a Model Form

问题描述

我有一个 Task 模型，其中包含任务和实体的外键：

I have a Task model that includes tasks and a foreign key to entities:

class Task(models.Model):
    task = models.CharField(max_length=500)
    entity = models.ForeignKey(Entity)

我有一个与 Task ：

class Entity(models.Model):
    entity = models.CharField(max_length=50)
    type = models.CharField(max_length=50)
    def __str__(self):
        return self.entity

任务放入模型表单：

class TaskForm(ModelForm):
    class Meta:
        model = Task
        fields = [
            'task',
            'entity'
        ]

模型表单显示在模板中，如下所示：

The Model Form is displayed in the template like this:

{{ form.task }}
{{ form.instance.entity }}

我应如何包括 {{form.instance.type}} 的等价内容？这将涉及以某种方式包含相同模型形式的两个 __ str __ 表示形式。我已经看到 label_from_instance 用于覆盖模型表单，但这似乎只能通过ModelChoiceFields来实现。另外，它将字段显示为小部件而不是文本（例如 form.instance ）。

How would I include the equivalent of {{ form.instance.type }}? This would involve somehow including two __str__ representations in the same model form. I have seen label_from_instance used in overriding the model form, but this looks like it's only possible with ModelChoiceFields. In addition, it would render the field as a widget rather than text (like form.instance).

推荐答案

在模板中， form.instance.entity 是实例的相关的实体。如果要显示 type 字段，则可以简单地使用：

In the template, form.instance.entity is the instance's related entity. If you want to display the type field, you can simply use:

{{ form.instance.entity.type }}

要回答标题中的问题，每个模型只能有一个 __ str __ 方法。您可以定义另一个返回字符串的方法或属性，但是如果您只想显示 type 字段，则无需执行此操作。

To answer the question in your title, each model can only have one __str__ method. You could define another method or property that returns a string, but there's no need to do this if you just want to display the type field.

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