[admin] Add search in subnet

Closes #39

Author: purhan

openwisp_ipam/static/openwisp-ipam/js/subnet.js

@@ -58,6 +58,14 @@ function initHostsInfiniteScroll($, current_subnet, address_add_url, address_cha
         });
         return div;
     }
+    $(document).ready(function () {
+        $("#subnet-search").on("keyup", function () {
+            var searchQuery = $(this).val().toLowerCase();
+            $("#subnet-visual div a").filter(function () {
+                $(this).toggle($(this).text().toLowerCase().indexOf(searchQuery) > -1)
+            });
+        });
+    });
     function appendPage() {
         $('.subnet-visual').append(pageContainer(fetchedPages[lastRenderedPage]));
         if (lastRenderedPage >= renderedPages) {

openwisp_ipam/templates/admin/openwisp-ipam/subnet/change_form.html

@@ -28,8 +28,10 @@ <h2>{% trans 'Network Hierarchical View' %}</h2>
 <div id="graph"></div>
 
 <h3>{% trans 'Subnet Visual Display' %}</h3>
-<section class="subnet-visual{% if original.subnet.version == 6 %} ipv6{% endif %}">
-</section>
+<input id="subnet-search" placeholder="Search">
+  <section id="subnet-visual" class="subnet-visual{% if original.subnet.version == 6 %} ipv6{% endif %}">
+  </section>
+</input>
 {% endif %}
 {% endblock %}