Merge pull request #94 from rakyll/endcursor

datastore: Add support for end cursors

Author: Burcu Dogan

lib/datastore/entity.js

@@ -304,6 +304,9 @@ var queryToQueryProto = function(q) {
   if (q.startVal) {
     query.startCursor = q.startVal;
   }
+  if (q.endVal) {
+    query.endCursor = q.endVal;
+  }
   if (q.offsetVal > 0) {
     query.offset = q.offsetVal;
   }

lib/datastore/query.js

@@ -27,6 +27,7 @@ function Query(namespace, kinds) {
 
   // pagination
   this.startVal = null;
+  this.endVal = null;
   this.limitVal = -1;
   this.offsetVal = -1;
 }
@@ -79,6 +80,12 @@ Query.prototype.start = function(start) {
   return q;
 }
 
+Query.prototype.end = function(end) {
+  var q = util.extend(this, new Query());
+  q.endVal = end;
+  return q;
+};
+
 Query.prototype.limit = function(n) {
   var q = util.extend(this, new Query());
   q.limitVal = n;

test/datastore.query.js

@@ -106,9 +106,12 @@ describe('Query', function() {
     done();
   });
 
-  it('should allow page start tokens', function(done) {
-    var q = ds.createQuery(['kind1']).start('abc123');
+  it('should allow page start and end tokens', function(done) {
+    var q = ds.createQuery(['kind1'])
+        .start('abc123')
+        .end('def987');
     assert.strictEqual(q.startVal, 'abc123');
+    assert.strictEqual(q.endVal, 'def987');
     done();
   });
 
@@ -119,7 +122,8 @@ describe('Query', function() {
         .filter('name =', 'Burcu')
         .order('-count')
         .groupBy(['count'])
-        .start('cursor')
+        .start('start-cursor')
+        .end('end-cursor')
         .offset(5)
         .limit(10);
     assert.deepEqual(entity.queryToQueryProto(q), queryProto);

test/testdata/proto_query.json

@@ -1 +1 @@
-{"projection":[{"property":{"name":"name"}},{"property":{"name":"count"}}],"kinds":[{"name":"Kind"}],"filter":{"compositeFilter":{"filters":[{"propertyFilter":{"property":{"name":"count"},"operator":"GREATER_THAN_OR_EQUAL","value":{"integerValue":5}}},{"propertyFilter":{"property":{"name":"name"},"operator":"EQUAL","value":{"stringValue":"Burcu"}}}],"operator":"AND"}},"order":[{"property":{"name":"count"},"direction":"DESCENDING"}],"groupBy":[{"name":"count"}],"startCursor":"cursor","offset":5,"limit":10}
+{"projection":[{"property":{"name":"name"}},{"property":{"name":"count"}}],"kinds":[{"name":"Kind"}],"filter":{"compositeFilter":{"filters":[{"propertyFilter":{"property":{"name":"count"},"operator":"GREATER_THAN_OR_EQUAL","value":{"integerValue":5}}},{"propertyFilter":{"property":{"name":"name"},"operator":"EQUAL","value":{"stringValue":"Burcu"}}}],"operator":"AND"}},"order":[{"property":{"name":"count"},"direction":"DESCENDING"}],"groupBy":[{"name":"count"}],"startCursor":"start-cursor","endCursor": "end-cursor","offset":5,"limit":10}