[#51,backend/memory][s]: simple createDataset method to create in-memory dataset from raw array of hashes (and optional other info).

src/backend/memory.js

@@ -2,6 +2,43 @@ this.recline = this.recline || {};
 this.recline.Backend = this.recline.Backend || {};
 
 (function($, my) {
+  // ## createDataset
+  //
+  // Convenience function to create a simple 'in-memory' dataset in one step.
+  //
+  // @param data: list of hashes for each document/row in the data ({key:
+  // value, key: value})
+  // @param fields: (optional) list of field hashes (each hash defining a hash
+  // as per recline.Model.Field). If fields not specified they will be taken
+  // from the data.
+  // @param metadata: (optional) dataset metadata - see recline.Model.Dataset.
+  // If not defined (or id not provided) id will be autogenerated.
+  my.createDataset = function(data, fields, metadata) {
+    if (!metadata) {
+      var metadata = {};
+    }
+    if (!metadata.id) {
+      metadata.id = String(Math.floor(Math.random() * 100000000) + 1);
+    }
+    var backend = recline.Model.backends['memory'];
+    var datasetInfo = {
+      documents: data,
+      metadata: metadata
+    };
+    if (fields) {
+      datasetInfo.fields = fields;
+    } else {
+      if (data) {
+        datasetInfo.fields = _.keys(data[0]);
+      }
+    }
+    backend.addDataset(datasetInfo);
+    var dataset = new recline.Model.Dataset({id: metadata.id}, 'memory');
+    dataset.fetch();
+    return dataset;
+  };
+
+
   // ## Memory Backend - uses in-memory data
   //
   // To use it you should provide in your constructor data:

test/backend.test.js

@@ -25,6 +25,17 @@ function makeBackendDataset() {
   return dataset;
 }
 
+test('Memory Backend: createDataset', function () {
+  var dataset = recline.Backend.createDataset(memoryData.documents, memoryData.fields, memoryData.metadata);
+  equal(memoryData.metadata.id, dataset.id);
+});
+
+test('Memory Backend: createDataset 2', function () {
+  var dataset = recline.Backend.createDataset(memoryData.documents);
+  dataset.query();
+  equal(memoryData.documents.length, dataset.currentDocuments.length);
+});
+
 test('Memory Backend: basics', function () {
   var dataset = makeBackendDataset();
   expect(3);