[model][m]: working Webstore Backend (fixes #8).

src/model.js

@@ -20,6 +20,13 @@ recline.DocumentList = Backbone.Collection.extend({
   model: recline.Document
 })
 
+// Backends section
+// ================
+
+recline.setBackend = function(backend) {
+  Backbone.sync = backend.sync;
+};
+
 // Backend which just caches in memory
 // 
 // Does not need to be a backbone model but provides some conveience
@@ -73,7 +80,68 @@ recline.BackendMemory = Backbone.Model.extend({
  }
 });
 
-recline.setBackend = function(backend) {
-  Backbone.sync = backend.sync;
-};
-
+// Webstore Backend for connecting to the Webstore
+//
+// Designed to only attached to only dataset and one dataset only ...
+// Could generalize to support attaching to different datasets
+recline.BackendWebstore = Backbone.Model.extend({
+  // require url attribute in initialization data
+  initialize: function() {
+    this.webstoreTableUrl = this.get('url');
+  }, 
+  getDataset: function(id) {
+    var dataset = new recline.Dataset({
+      id: id
+    });
+    dataset.backend = this;
+    return dataset;
+  },
+  sync: function(method, model, options) {
+    if (method === "read") {
+      // this switching on object type is rather horrible
+      // think may make more sense to do work in individual objects rather than in central Backbone.sync
+      if (this.__type__ == 'Dataset') {
+        // get the schema and return
+        var base = this.backend.get('url');
+        var schemaUrl = base + '/schema.json';
+        var jqxhr = $.ajax({
+          url: schemaUrl,
+          dataType: 'jsonp',
+          jsonp: '_callback'
+          });
+        var dfd = $.Deferred();
+        jqxhr.then(function(schema) {
+          headers = _.map(schema.data, function(item) {
+            return item.name;
+          });
+          dataset.set({
+            headers: headers
+          });
+          dataset.rowCount = schema.count;
+          dfd.resolve(dataset, jqxhr);
+        });
+        return dfd.promise();
+      }
+    }
+  },
+  getRows: function(datasetId, numRows, start) {
+    if (start === undefined) {
+      start = 0;
+    }
+    if (numRows === undefined) {
+      numRows = 10;
+    }
+    var base = this.get('url');
+    var jqxhr = $.ajax({
+      url: base + '.json',
+      dataType: 'jsonp',
+      jsonp: '_callback',
+      cache: true
+      });
+    var dfd = $.Deferred();
+    jqxhr.then(function(results) {
+      dfd.resolve(results.data);
+    });
+    return dfd.promise();
+ }
+});