Django 编辑模型实例无法找到该实例

Question

I'm in the process of making a Recipe Book. For some reason, whenever I try to pull up a recipe from the DB to edit it, I keep getting an error where it can't find the recipe I've specified. I'm using slugs, and my logic is that I'm going from a detailView where I've already pulled up the db information, to an updateView. I'm attempting to pass the recipe object I already pulled from the detailView to the updateView, but when I do, it keeps telling me that it can't find the recipe specified.

views.py: The base views I'm calling here are only providing a default post method for handling a search so that I don't have to put it in for every view I create so I have some code reusability

class RecipeDetailView(BaseDetailView):
    model = Recipe
    template_name = 'RecipeBook/recipe_detail.html'
    context_object_name = 'recipe_view'
    queryset = None
    slug_field = 'slug'
    slug_url_kwarg = 'slug'

    def get_context_data(self, *args, **kwargs):
        context = super(RecipeDetailView, self).get_context_data()
        recipe = self.object
        recipe.ingredients = recipe.ingredients_list.split('\n')

        context['recipe'] = recipe

        return context

class RecipeEditView(BaseUpdateView):
    model = Recipe
    template_name = 'RecipeBook/edit_recipe.html'
    context_object_name = 'recipe_edit'
    queryset = None
    slug_field = 'slug'
    slug_url_kwarg = 'slug'
    form_class = RecipeForm

    def get_context_data(self, *args, **kwargs):
        context = super(RecipeEditView, self).get_context_data()
        recipe = self.object
        print(recipe.name)
        recipe.ingredients = recipe.ingredients_list.split('\n')
        recipe.categories_list = ""
        categories = Category.objects.filter(recipe=recipe)
        for category in categories:
            if category != categories[-1]:
                recipe.categories_list += (category + ", ")
            else:
                recipe.categories_list += category

        recipe_edit_form = RecipeForm(initial={'name': recipe.name, 'ingredients_list': recipe.ingredients,
                                               'directions': recipe.directions, 'prep_time': recipe.prep_time,
                                               'cook_time': recipe.cook_time, 'servings': recipe.servings,
                                               'source': recipe.source, 'category_input': recipe.categories_list})
        context['recipe'] = recipe
        context['recipe_edit_form'] = recipe_edit_form

        return context

models.py:

class Recipe(models.Model):
    id = models.AutoField(primary_key=True)
    name = models.CharField(max_length=100, default="")
    ingredients_list = models.TextField(default="")
    servings = models.IntegerField(default=0, null=True, blank=True)
    prep_time = models.IntegerField(default=0, null=True, blank=True)
    cook_time = models.IntegerField(default=0, null=True, blank=True)
    directions = models.TextField(default="")
    source = models.CharField(max_length=100, default="", null=True, blank=True)
    categories = models.ManyToManyField(Category, blank=True)
    slug = models.CharField(max_length=200, default="")

    def __str__(self):
        return self.name

urls.py

# ex: /Recipes/Grilled_Chicken/
    path('Recipes/<slug>/', views.RecipeDetailView.as_view(), name='view_recipe'),
    path('Recipes/<path:slug>/', views.RecipeDetailView.as_view(), name='view_recipe'),
    # ex: /Recipes/edit/Steak/
    path('Recipes/edit/<slug>/', views.RecipeEditView.as_view(), name='edit_recipe'),
    path('Recipes/edit/<path:slug>/', views.RecipeEditView.as_view(), name='edit_recipe'),

link in recipe_detail.html:

<a href="{% url 'RecipeBook:edit_recipe' recipe.slug %}" style="float: right">Edit Recipe</a>

I've been going nuts trying to figure it out. By everything that I have in here, the recipe that I'm pulling up in the detailView should be able to be passed to the editView, but every time I try to open up the edit_recipe page, it keeps telling me that it can't find the recipe specified. The URL that it generates shows the proper slug and link that it should though. I don't know what I'm missing at this point...

Answer 1

试试这个方法：

<a href="{% url 'RecipeBook:edit_recipe' recipe_view.slug %}" style="float: right">Edit Recipe</a>

Answer 2

I ended up having to go back through and change the view to be a DetailView. That was the only way I could get the recipe instance to be pushed through. There's something very specific about using an update view with models that isn't very clear...

Once I changed to a DetailView, the page would populate with the form initialized to the recipe values. I could then make tweaks to make sure everything worked from there.

Thanks for those who responded, it at least got my brain working in a different direction to get this figured out.