Enable breadcrumb support, use it on the login view

home/views.py

@@ -1,5 +1,8 @@
 from django.shortcuts import get_object_or_404, render
 from users.models import User
+from lemoncurry import breadcrumbs
+
+breadcrumbs.add('home:index', 'home')
 
 
 def index(request):

lemonauth/views.py

@@ -1,4 +1,7 @@
 from django.contrib.auth import views as auth_views
+from lemoncurry import breadcrumbs
+
+breadcrumbs.add(route='lemonauth:login', label='login', parent='home:index')
 
 login = auth_views.LoginView.as_view(
     template_name='lemonauth/login.html',

lemoncurry/breadcrumbs.py

@@ -0,0 +1,15 @@
+breadcrumbs = {}
+
+
+def add(route, label, parent=None):
+    breadcrumbs[route] = {'label': label, 'route': route, 'parent': parent}
+
+
+def find(route):
+    crumbs = []
+    while route:
+        crumb = breadcrumbs[route]
+        crumbs.append(crumb)
+        route = crumb['parent']
+    crumbs.reverse()
+    return crumbs

lemoncurry/static/lemoncurry/css/layout.styl

@@ -20,9 +20,16 @@ body
 	background-color $base00
 	color $base07
 	> header
+		> .navbar
 			background-color $base01
 			#navbar
 				justify-content space-between
+		> .breadcrumbs
+			background-color $base02
+			> .breadcrumb
+				background-color transparent
+				border-radius 0
+
 
 	> main
 		margin 2rem

lemoncurry/templates/lemoncurry/layout.html

@@ -29,6 +29,9 @@
 					{% nav_right request %}
 				</div>
 			</nav>
+			{% if request.resolver_match.view_name %}
+			{% nav_crumbs request.resolver_match.view_name %}
+			{% endif %}
 		</header>
 
 		<main>

lemoncurry/templates/lemoncurry/tags/breadcrumbs.html

@@ -0,0 +1,14 @@
+{% if crumbs %}
+<nav class="breadcrumbs" aria-label="breadcrumb" role="navigation">
+	<ol class="breadcrumb">
+		{% for crumb in crumbs %}
+		<li class="breadcrumb-item">
+			<a href="{% url crumb.route %}">{{ crumb.label }}</a>
+		</li>
+		{% endfor %}
+		<li class="breadcrumb-item active" aria-current="page">
+			{{ current.label }}
+		</li>
+	</ol>
+</nav>
+{% endif %}

lemoncurry/templatetags/lemoncurry_tags.py

@@ -7,6 +7,8 @@ from django import template
 from django.conf import settings
 from django.urls import reverse
 
+from .. import breadcrumbs
+
 register = template.Library()
 cache = SimpleNamespace(package_json=None)
 
@@ -50,3 +52,10 @@ def nav_right(request):
             MenuItem(label='log in', icon='fa fa-sign-in', url='lemonauth:login'),
         )
     return {'items': items}
+
+
+@register.inclusion_tag('lemoncurry/tags/breadcrumbs.html')
+def nav_crumbs(route):
+    crumbs = breadcrumbs.find(route)
+    current = crumbs.pop()
+    return {'crumbs': crumbs, 'current': current}