implement pagination in back-end

gazetteer/places/views.py

@@ -3,6 +3,7 @@ from django.shortcuts import render_to_response, get_object_or_404
 from ox.django.shortcuts import render_to_json_response
 from django.template import RequestContext
 from models import Feature, FeatureType, AuthorityRecord
+from django.core.paginator import Paginator, InvalidPage, EmptyPage
 
 def search(request):
     d = RequestContext(request, {})
@@ -12,6 +13,8 @@ def search_json(request):
     search_term = request.GET.get("q", "")
     threshold = request.GET.get("threshold", 0.5)
     bbox = request.GET.get("bbox", False)
+    page = request.GET.get("page", 1)
+    count = request.GET.get("count", 100)
     country = request.GET.get("adm0", "US") # right now, unused
     adm1 = request.GET.get("adm1", "")
     adm2 = request.GET.get("adm2", "")
@@ -33,10 +36,22 @@ def search_json(request):
     if not bbox and not search_term:
         return render_to_json_response({'error': 'must supply either a valid `bbox` or a `search` parameter'})
 
-    features_qset = Feature.search.find(bbox=bbox, text=search_term, threshold=threshold, adm1=adm1, adm2=adm2, srid=srid)[0:20]
-    features = [f.get_geojson(srid) for f in features_qset]
+    features_qset = Feature.search.find(bbox=bbox, text=search_term, threshold=threshold, adm1=adm1, adm2=adm2, srid=srid)
+    total_results = features_qset.count()
+    paginator = Paginator(features_qset, count)
+    num_pages = paginator.num_pages
+
+    try:
+        results = paginator.page(page)
+    except (EmptyPage, InvalidPage):
+        results = paginator.page(paginator.num_pages)
+    features = [f.get_geojson(srid) for f in results.object_list]
+
     d = {
         'type': 'FeatureCollection',
+        'results': total_results,
+        'current_page': page,
+        'pages': num_pages,
         'features': features
     }
     return render_to_json_response(d)