[#62,facets,backend/memory][m]: add faceting support to memory backend.

demo/js/app.js

@@ -94,26 +94,7 @@ function localDataset() {
   var backend = new recline.Backend.Memory();
   backend.addDataset(inData);
   var dataset = new recline.Model.Dataset({id: datasetId}, backend);
-  // TODO: auto-compute in Memory backend ??
+  dataset.queryState.addFacet('country');
-  dataset.facets = new recline.Model.FacetList([
-    {
-      id: 'country',
-      result: [
-        {
-          term: 'UK',
-          count: 3
-        },
-        {
-          term: 'DE',
-          count: 2
-        },
-        {
-          term: 'US',
-          count: 1
-        }
-      ]
-    }
-  ]);
   return dataset;
 }
 

src/backend/memory.js

@@ -115,9 +115,10 @@ this.recline.Backend = this.recline.Backend || {};
       }
     },
     query: function(model, queryObj) {
+      var dfd = $.Deferred();
+      var out = {};
       var numRows = queryObj.size;
       var start = queryObj.from;
-      var dfd = $.Deferred();
       results = this.datasets[model.id].documents;
       // not complete sorting!
       _.each(queryObj.sort, function(sortObj) {
@@ -127,11 +128,48 @@ this.recline.Backend = this.recline.Backend || {};
           return (sortObj[fieldName].order == 'asc') ? _out : -1*_out;
         });
       });
+      out.facets = this._computeFacets(results, queryObj);
       var total = results.length;
-      var out = this._docsToQueryResult(results.slice(start, start+numRows));
+      resultsObj = this._docsToQueryResult(results.slice(start, start+numRows));
+      _.extend(out, resultsObj);
       out.total = total;
       dfd.resolve(out);
       return dfd.promise();
+    },
+
+    _computeFacets: function(documents, queryObj) {
+      var facetResults = {};
+      if (!queryObj.facets) {
+        return facetsResults;
+      }
+      _.each(queryObj.facets, function(query, facetId) {
+        facetResults[facetId] = new recline.Model.Facet({id: facetId}).toJSON();
+        facetResults[facetId].termsall = {};
+      });
+      // faceting
+      _.each(documents, function(doc) {
+        _.each(queryObj.facets, function(query, facetId) {
+          var fieldId = query.terms.field;
+          var val = doc[fieldId];
+          var tmp = facetResults[facetId];
+          if (val) {
+            tmp.termsall[val] = tmp.termsall[val] ? tmp.termsall[val] + 1 : 1;
+          } else {
+            tmp.missing = tmp.missing + 1;
+          }
+        });
+      });
+      _.each(queryObj.facets, function(query, facetId) {
+        var tmp = facetResults[facetId];
+        var terms = _.map(tmp.termsall, function(count, term) {
+          return { term: term, count: count };
+        });
+        tmp.terms = _.sortBy(terms, function(item) {
+          // want descending order
+          return -item.count;
+        });
+      });
+      return facetResults;
     }
   });
   recline.Model.backends['memory'] = new my.Memory();

src/model.js

@@ -152,15 +152,25 @@ my.Query = Backbone.Model.extend({
     facets[fieldId] = {
       terms: { field: fieldId }
     };
-    this.set({facets: facets});
+    this.set({facets: facets}, {silent: true});
-    // for some reason this does not trigger automatically ...
+    this.trigger('facet:add', this);
-    this.trigger('change', this);
   }
 });
 
 
 // ## A Facet (Result)
 my.Facet = Backbone.Model.extend({
+  defaults: {
+    _type: 'terms',
+    // total number of tokens in the facet
+    total: 0,
+    // number of facet values not included in the returned facets
+    other: 0,
+    // number of documents which have no value for the field
+    missing: 0,
+    // term object ({term: , count: ...})
+    terms: []
+  }
 });
 
 // ## A Collection/List of Facets

test/backend.test.js

@@ -7,14 +7,14 @@ var memoryData = {
     , name: '1-my-test-dataset' 
     , id: 'test-dataset'
   },
-  fields: [{id: 'id'}, {id: 'x'}, {id: 'y'}, {id: 'z'}],
+  fields: [{id: 'x'}, {id: 'y'}, {id: 'z'}, {id: 'country'}, {id: 'label'}],
   documents: [
-    {id: 0, x: 1, y: 2, z: 3}
+    {id: 0, x: 1, y: 2, z: 3, country: 'DE', label: 'first'}
-    , {id: 1, x: 2, y: 4, z: 6}
+    , {id: 1, x: 2, y: 4, z: 6, country: 'UK', label: 'second'}
-    , {id: 2, x: 3, y: 6, z: 9}
+    , {id: 2, x: 3, y: 6, z: 9, country: 'US', label: 'third'}
-    , {id: 3, x: 4, y: 8, z: 12}
+    , {id: 3, x: 4, y: 8, z: 12, country: 'UK', label: 'fourth'}
-    , {id: 4, x: 5, y: 10, z: 15}
+    , {id: 4, x: 5, y: 10, z: 15, country: 'UK', label: 'fifth'}
-    , {id: 5, x: 6, y: 12, z: 18}
+    , {id: 5, x: 6, y: 12, z: 18, country: 'DE', label: 'sixth'}
   ]
 };
 
@@ -32,8 +32,8 @@ test('Memory Backend: createDataset', function () {
 
 test('Memory Backend: createDataset 2', function () {
   var dataset = recline.Backend.createDataset(memoryData.documents);
-  equal(dataset.fields.length, 4);
+  equal(dataset.fields.length, 6);
-  deepEqual(['id', 'x', 'y', 'z'], dataset.fields.pluck('id'));
+  deepEqual(['id', 'x', 'y', 'z', 'country', 'label'], dataset.fields.pluck('id'));
   dataset.query();
   equal(memoryData.documents.length, dataset.currentDocuments.length);
 });
@@ -73,11 +73,34 @@ test('Memory Backend: query sort', function () {
       {'y': {order: 'desc'}}
     ]
   };
-  dataset.query(queryObj).then(function(docs) {
+  dataset.query(queryObj).then(function() {
     var doc0 = dataset.currentDocuments.models[0].toJSON();
     equal(doc0.x, 6);
   });
 });
+
+test('Memory Backend: facet', function () {
+  var dataset = makeBackendDataset();
+  dataset.queryState.addFacet('country');
+  dataset.query().then(function() {
+    equal(dataset.facets.length, 1);
+    var exp = [
+      {
+        term: 'UK',
+        count: 3
+      },
+      {
+        term: 'DE',
+        count: 2
+      },
+      {
+        term: 'US',
+        count: 1
+      }
+    ];
+    deepEqual(dataset.facets.get('country').toJSON().terms, exp);
+  });
+});
  
 test('Memory Backend: update and delete', function () {
   var dataset = makeBackendDataset();
@@ -379,7 +402,6 @@ test("GDoc Backend", function() {
   );
 
   var stub = sinon.stub($, 'getJSON', function(options, cb) {
-    console.log('options are', options, cb);
     var partialUrl = 'spreadsheets.google.com';
     if (options.indexOf(partialUrl) != -1) {
       cb(sample_gdocs_spreadsheet_data)
@@ -387,12 +409,10 @@ test("GDoc Backend", function() {
   });
 
   dataset.fetch().then(function(dataset) {
-    console.log('inside dataset:', dataset, dataset.fields, dataset.get('data'));
     deepEqual(['column-2', 'column-1'], _.pluck(dataset.fields.toJSON(), 'id'));
     //equal(null, dataset.docCount)
     dataset.query().then(function(docList) {
       equal(3, docList.length);
-      console.log(docList.models[0]);
       equal("A", docList.models[0].get('column-1'));
       // needed only if not stubbing
       start();