hotwire-django#8 - Allow users to favorite articles

articles/views.py

@@ -1,16 +1,24 @@
-from django.shortcuts import get_object_or_404
+
 from django.urls import reverse_lazy
 from django.shortcuts import render
 from django.http import HttpResponseRedirect
-from django.contrib.auth.decorators import login_required
-from django.contrib.auth.mixins import LoginRequiredMixin
+from django.contrib.auth.mixins import LoginRequiredMixin, UserPassesTestMixin
 from django.views.generic.edit import CreateView, UpdateView
+from django.db.models import Count
+
 from .models import Article
 from .forms import ArticleForm
 
 
+class IsAuthenticatedOrReadOnly(UserPassesTestMixin):
+    def test_func(self):
+        return self.request.method == 'GET' or self.request.user.is_authenticated
+
+
 def view(req, slug):
-    return render(req, "articles/detail.html")
+    return render(req, "articles/detail.html", {
+        "article": Article.objects.get(slug=slug)
+    })
 
 
 class EditArticle(LoginRequiredMixin, UpdateView):
@@ -55,3 +63,32 @@ def form_valid(self, form):
         """
         self.object = form.save(self.request.user)
         return HttpResponseRedirect(self.get_success_url(), status=303)
+
+
+class FavoriteArticle(IsAuthenticatedOrReadOnly, UpdateView):
+    fields = []
+    template_name = 'articles/_favorite.html'
+    queryset = Article.objects.select_related('author__user').annotate(
+        favorited_by__count=Count('favorited_by')
+    )
+
+    def get_success_url(self):
+        return reverse_lazy('article_favorite', kwargs={'slug': self.object.slug})
+
+    def get_context_data(self, **kwargs):
+        context = super().get_context_data(**kwargs)
+
+        if self.request.user.is_authenticated:
+            context['has_favorited'] = self.request.user.profile.has_favorited(self.object)
+
+        return context
+
+    def form_valid(self, form):
+        profile = self.request.user.profile
+
+        if profile.has_favorited(self.object):
+            profile.unfavorite(self.object)
+        else:
+            profile.favorite(self.object)
+
+        return HttpResponseRedirect(self.get_success_url(), status=303)

realworld/urls.py

@@ -23,6 +23,7 @@
     path("admin/", admin.site.urls),
     path("", home_views.index, name="index"),
     path("article/<slug:slug>/", articles_views.view, name="article_view"),
+    path("article/<slug:slug>/favorite/", articles_views.FavoriteArticle.as_view(), name="article_favorite"),
     path("editor/<slug:slug>/", articles_views.EditArticle.as_view(), name="article_edit"),
     path("editor/", articles_views.CreateArticle.as_view(), name="article_create"),
     path("@<slug:profile>/", profile_views.view, name="profile_view"),

templates/articles/_favorite.html

@@ -0,0 +1,24 @@
+<turbo-frame id="favorite-button-{{ article.slug }}">
+  {% if request.user.is_authenticated %}
+    <form method="POST" action="{% url 'article_favorite' article.slug %}" class="list-inline-item">
+      {% csrf_token %}
+
+      {% if has_favorited %}
+        <button class="btn btn-sm btn-primary">
+          <i class="ion-heart"></i>
+          &nbsp; Unfavorite Post <span class="counter">({{ article.favorited_by__count }})</span>
+        </button>
+      {% else %}
+        <button class="btn btn-sm btn-outline-primary">
+          <i class="ion-heart"></i>
+          &nbsp; Favorite Post <span class="counter">({{ article.favorited_by__count }})</span>
+        </button>
+      {% endif %}
+    </form>
+  {% else %}
+    <a data-turbo="false" href="{% url 'login' %}" class="btn btn-sm btn-outline-primary">
+      <i class="ion-heart"></i>
+      &nbsp; Login to Favorite <span class="counter">({{ article.favorited_by__count }})</span>
+    </a>
+  {% endif %}
+</turbo-frame>

templates/articles/detail.html

@@ -15,10 +15,11 @@ <h1>How to build webapps that scale</h1>
           &nbsp; Follow Eric Simons <span class="counter">(10)</span>
         </button>
         &nbsp;&nbsp;
-        <button class="btn btn-sm btn-outline-primary">
-          <i class="ion-heart"></i>
-          &nbsp; Favorite Post <span class="counter">(29)</span>
-        </button>
+
+        <turbo-frame
+          id="favorite-button-{{ article.slug }}"
+          src="{% url 'article_favorite' article.slug %}"
+        />
       </div>
     </div>
   </div>
@@ -50,10 +51,10 @@ <h2 id="introducing-ionic">Introducing RealWorld.</h2>
           &nbsp; Follow Eric Simons <span class="counter">(10)</span>
         </button>
         &nbsp;
-        <button class="btn btn-sm btn-outline-primary">
-          <i class="ion-heart"></i>
-          &nbsp; Favorite Post <span class="counter">(29)</span>
-        </button>
+        <turbo-frame
+          id="favorite-button-{{ article.slug }}"
+          src="{% url 'article_favorite' article.slug %}"
+        />
       </div>
     </div>