Add tag filter list to package page

app/blueprints/packages/packages.py

@@ -80,12 +80,15 @@ def list_all():
 		qb.show_discarded = True
 		topics = qb.buildTopicQuery().all()
 
-	tags = Tag.query.all()
+	tags = db.session.query(func.count(Tags.c.tag_id), Tag) \
+  		.select_from(Tag).outerjoin(Tags).group_by(Tag.id).order_by(db.asc(Tag.title))
+
+	selected_tags = set(qb.tags)
+
 	return render_template("packages/list.html", \
-			title=title, packages=query.items, topics=topics, \
+			title=title, packages=query.items, pagination=query, \
-			query=search, tags=tags, type=type_name, \
+			query=search, tags=tags, selected_tags=selected_tags, type=type_name, \
-			authors=authors, packages_count=query.total, \
+			authors=authors, packages_count=query.total, topics=topics)
-			pagination=query)
 
 
 def getReleases(package):

app/templates/packages/list.html

@@ -19,7 +19,8 @@
 		</p>
 	{% endif %}
 
-
+	<div class="row">
+		<div class="col-md-9">
 			{% from "macros/packagegridtile.html" import render_pkggrid %}
 			{{ render_pkggrid(packages) }}
 
@@ -34,5 +35,32 @@
 				{% from "macros/topics.html" import render_topics %}
 				{{ render_topics(topics, current_user) }}
 			{% endif %}
+		</div>
+
+		<aside class="col-md-3">
+			<p class="text-muted">Filter by tags</p>
+
+			{% for pair in tags %}
+				{% set count = pair[0] %}
+				{% set tag = pair[1] %}
+
+				{% if tag in selected_tags %}
+					<a class="badge badge-primary"
+							href="{{ url_set_query(page=1, _remove={ 'tag': tag.name }) }}">
+
+						{{ tag.title }}
+						({{ count }})
+					</a>
+				{% else %}
+					<a class="badge badge-secondary"
+							href="{{ url_set_query(page=1, _add={ 'tag': tag.name }) }}">
+
+						{{ tag.title }}
+						({{ count }})
+					</a>
+				{% endif %}
+			{% endfor %}
+		</aside>
+	</div>
 
 {% endblock %}

app/utils.py

@@ -22,6 +22,7 @@ from .models import *
 from . import app
 import random, string, os, imghdr
 from urllib.parse import urljoin
+from werkzeug.datastructures import MultiDict
 
 # These are given to Jinja in template_filters.py
 
@@ -33,9 +34,26 @@ def abs_url(path):
 	return urljoin(app.config["BASE_URL"], path)
 
 def url_set_query(**kwargs):
-	args = dict(request.args)
+	args = MultiDict(request.args)
-	args.update(kwargs)
+
-	return url_for(request.endpoint, **args)
+	for key, value in kwargs.items():
+		if key == "_add":
+			for key2, value_to_add in value.items():
+				values = set(args.getlist(key2))
+				values.add(value_to_add)
+				args.setlist(key2, list(values))
+		elif key == "_remove":
+			for key2, value_to_remove in value.items():
+				values = set(args.getlist(key2))
+				values.discard(value_to_remove)
+				args.setlist(key2, list(values))
+		else:
+			args.setlist(key, [ value ])
+
+
+	dargs = dict(args.lists())
+
+	return url_for(request.endpoint, **dargs)
 
 def get_int_or_abort(v, default=None):
 	if v is None: