datastore: scope Key creation to include NS. fixes #116.

README.md

@@ -99,12 +99,12 @@ TODO
 Get operations require a valid key to retrieve the key identified entity from Datastore. Skip to the "Querying" section if you'd like to learn more about querying against Datastore.
 
 ~~~~ js
-ds.get(datastore.key('Company', 123), function(err, entity) {});
+ds.get(ds.key('Company', 123), function(err, entity) {});
 
 // alternatively, you can retrieve multiple entities at once.
 ds.get([
-    datastore.key('Company', 123),
-    datastore.key('Product', 'Computer')
+    ds.key('Company', 123),
+    ds.key('Product', 'Computer')
 ], function(err, entities) {});
 ~~~~
 
@@ -114,15 +114,15 @@ To learn more about keys and incomplete keys, skip to the Keys section.
 
 ~~~~ js
 ds.save({
-    key: datastore.key('Company', null), data: {/*...*/}
+    key: ds.key('Company', null), data: {/*...*/}
 }, function(err, key) {
     // First arg is an incomplete key for Company kind.
     // console.log(key) will output ['Company', 599900452312].
 });
 // alternatively, you can save multiple entities at once.
 ds.save([
-    { key: datastore.key('Company', 123), data: {/*...*/} },
-    { key: datastore.key('Product', 'Computer'), data: {/*...*/} }
+    { key: ds.key('Company', 123), data: {/*...*/} },
+    { key: ds.key('Product', 'Computer'), data: {/*...*/} }
 ], function(err, keys) {
     // if the first key was incomplete, keys[0] will return the generated key.
 });
@@ -136,10 +136,10 @@ ds.delete(['Company', 599900452312], function(err) {});
 // alternatively, you can delete multiple entities of different
 // kinds at once.
 ds.delete([
-    datastore.key('Company', 599900452312),
-    datastore.key('Company', 599900452315),
-    datastore.key('Office', 'mtv'),
-    datastore.key('Company', 123, 'Employee', 'jbd')
+    ds.key('Company', 599900452312),
+    ds.key('Company', 599900452315),
+    ds.key('Office', 'mtv'),
+    ds.key('Company', 123, 'Employee', 'jbd')
 ], function(err) {});
 ~~~~
 
@@ -178,14 +178,14 @@ stored as properties is not currently supported.
 
 ~~~~ js
 var q = ds.createQuery('Company')
-    .filter('__key__ =', datastore.key('Company', 'Google'))
+    .filter('__key__ =', ds.key('Company', 'Google'))
 ~~~~
 
 In order to filter by ancestors, use `hasAncestor` helper.
 
 ~~~ js
 var q = ds.createQuery('Child')
-    .hasAncestor(datastore.key('Parent', 123));
+    .hasAncestor(ds.key('Parent', 123));
 ~~~
 
 ##### Sorting
@@ -223,25 +223,16 @@ var q = ds.createQuery('Company')
 #### Allocating IDs (ID generation)
 
 You can generate IDs without creating entities. The following call will create
-100 new IDs from the Company kind which exists under the default namespace.
+100 new IDs from the Company kind which exists under the dataset's namespace. If
+no namespace was provided when the dataset was created, the default namespace
+will be used.
 
 ~~~~ js
-ds.allocateIds(datastore.key('Company', null), 100, function(err, keys) {
+ds.allocateIds(ds.key('Company', null), 100, function(err, keys) {
 
 });
 ~~~~
 
-You may prefer to create IDs from a non-default namespace by providing
-an incomplete key with a namespace. Similar to the previous example, the
-call below will create 100 new IDs, but from the Company kind that exists
-under the "ns-test" namespace.
-
-~~~~ js
-var incompleteKey = datastore.key('ns-test', 'Company', null);
-ds.allocateIds(incompleteKey, 100, function(err, keys) {
-});
-~~~~
-
 #### Transactions
 
 Datastore has support for transactions. Transactions allow you to perform

lib/common/util.js

@@ -163,3 +163,55 @@ function handleResp(err, resp, body, callback) {
 }
 
 module.exports.handleResp = handleResp;
+
+/**
+ * Get the type of a value.
+ *
+ * @private
+ *
+ * @return {string}
+ */
+function getType(value) {
+  return Object.prototype.toString.call(value).match(/\s(\w+)\]/)[1];
+}
+
+/**
+ * Check if an object is of the given type.
+ *
+ * @param {*} value - Value to compare to.
+ * @param {string} type - Type to check against object's value.
+ * @return {boolean}
+ *
+ * @example
+ * ```js
+ * is([1, 2, 3], 'array');
+ * // true
+ * ```
+ */
+function is(value, type) {
+  return getType(value).toLowerCase() === type.toLowerCase();
+}
+
+module.exports.is = is;
+
+/**
+ * Convert an object into an array.
+ *
+ * @param {object} object - Object to convert to an array.
+ * @return {array}
+ *
+ * @example
+ * ```js
+ * function aFunction() {
+ *   return toArray(arguments);
+ * }
+ *
+ * aFunction(1, 2, 3);
+ * // [1, 2, 3]
+ * ```
+ */
+function toArray(object) {
+  return [].slice.call(object);
+}
+
+module.exports.toArray = toArray;

lib/datastore/dataset.js

@@ -54,51 +54,94 @@ var SCOPES = [
  * @constructor
  * @alias module:datastore/dataset
  *
- * @param {object} options
- * @param {string} options.id - Dataset ID. This is your project ID from the
- *     Google Developers Console.
+ * @param {object=} options
+ * @param {string} options.projectId - Dataset ID. This is your project ID from
+ *     the Google Developers Console.
  * @param {string} options.keyFileName - Full path to the JSON key downloaded
  *     from the Google Developers Console.
+ * @param {string} options.namespace - Namespace to isolate transactions to.
  *
  * @example
  * ```js
  * var dataset = new Dataset({
- *   id: 'my-project',
+ *   projectId: 'my-project',
  *   keyFileName: '/path/to/keyfile.json'
  * });
  * ```
  */
-function Dataset(opts) {
-  opts = opts || {};
-  var id = opts.projectId;
+function Dataset(options) {
+  options = options || {};
 
   this.connection = new conn.Connection({
-    keyFilename: opts.keyFilename,
+    keyFilename: options.keyFilename,
     scopes: SCOPES
   });
-  this.id = id;
+  this.id = options.projectId;
+  this.namespace = options.namespace;
   this.transaction = this.createTransaction_();
 }
 
 /**
- * Create a query from the current dataset to query the specified kinds.
+ * Helper to create a Key object, scoped to the dataset's namespace by default.
+ *
+ * You may also specify a configuration object to define a namespace and path.
+ *
+ * @example
+ * ```js
+ * var key;
+ *
+ * // Create a key from the dataset's namespace.
+ * key = dataset.key('Company', 123);
+ *
+ * // Create a key from a provided namespace and path.
+ * key = dataset.key({
+ *   namespace: 'My-NS',
+ *   path: ['Company', 123]
+ * });
+ * ```
+ */
+Dataset.prototype.key = function(keyConfig) {
+  if (!util.is(keyConfig, 'object')) {
+    keyConfig = {
+      namespace: this.namespace,
+      path: util.toArray(arguments)
+    };
+  }
+  return new entity.Key(keyConfig);
+};
+
+
+/**
+ * Create a query from the current dataset to query the specified kinds, scoped
+ * to the namespace provided at the initialization of the dataset.
  *
  * @borrows {module:datastore/query} as createQuery
  *
+ * @param {string=} namespace - Optional namespace.
+ * @param {string|array} kinds - Kinds to query.
+ *
  * @example
  * ```js
- * var query = dataset.createQuery(['Lion', 'Chimp']);
- * var zooQuery = dataset.createQuery('zoo', ['Lion', 'Chimp']);
+ * var query;
+ *
+ * // If your dataset was scoped to a namespace at initialization, your query
+ * // will likewise be scoped to that namespace.
+ * query = dataset.createQuery(['Lion', 'Chimp']);
+ *
+ * // However, you may override the namespace per query.
+ * query = dataset.createQuery('AnimalNamespace', ['Lion', 'Chimp']);
+ *
+ * // You may also remove the namespace altogether.
+ * query = dataset.createQuery(null, ['Lion', 'Chimp']);
  * ```
  * @return {module:datastore/query}
  */
-Dataset.prototype.createQuery = function(ns, kinds) {
-  if (!kinds) {
-    kinds = ns;
-    ns = '';
+Dataset.prototype.createQuery = function(namespace, kinds) {
+  if (arguments.length === 1) {
+    kinds = util.arrayize(namespace);
+    namespace = this.namespace;
   }
-  kinds = util.arrayize(kinds);
-  return new Query(ns, kinds);
+  return new Query(namespace, util.arrayize(kinds));
 };
 
 /**

lib/datastore/entity.js

@@ -89,19 +89,18 @@ var SIGN_TO_ORDER = {
  * Build a Datastore Key object.
  *
  * @constructor
- * @param {...*} - Key descriptors.
+ * @param {object} - Configuration object.
+ * @param {...*} options.path - Key path.
+ * @param {string=} options.namespace - Optional namespace.
  *
  * @example
  * ```js
  * var key = new Key('Company', 123);
  * ```
  */
-function Key() {
-  if (arguments.length > 1) {
-    this.path_ = [].slice.call(arguments);
-  } else {
-    this.path_ = arguments[0];
-  }
+function Key(options) {
+  this.namespace_ = options.namespace;
+  this.path_ = options.path;
 }
 
 module.exports.Key = Key;
@@ -220,15 +219,17 @@ module.exports.entityFromEntityProto = entityFromEntityProto;
  * ```
  */
 function keyFromKeyProto(proto) {
-  var keyPath = [];
+  var keyOptions = {
+    path: []
+  };
   if (proto.partition_id && proto.partition_id.namespace) {
-    keyPath.push(proto.partition_id.namespace);
+    keyOptions.namespace = proto.partition_id.namespace;
   }
   proto.path_element.forEach(function(path) {
-    keyPath.push(path.kind);
-    keyPath.push(Number(path.id) || path.name || null);
+    keyOptions.path.push(path.kind);
+    keyOptions.path.push(Number(path.id) || path.name || null);
   });
-  return new Key(keyPath);
+  return new Key(keyOptions);
 }
 
 module.exports.keyFromKeyProto = keyFromKeyProto;
@@ -261,15 +262,8 @@ function keyToKeyProto(key) {
   if (keyPath.length < 2) {
     throw new Error('A key should contain at least a kind and an identifier.');
   }
-  var namespace = null;
-  var start = 0;
-  if (keyPath.length % 2 === 1) {
-    // the first item is the namespace
-    namespace = keyPath[0];
-    start = 1;
-  }
   var path = [];
-  for (var i = start; i < (keyPath.length - start); i += 2) {
+  for (var i = 0; i < keyPath.length; i += 2) {
     var p = { kind: keyPath[i] };
     var val = keyPath[i+1];
     if (val) {
@@ -285,9 +279,9 @@ function keyToKeyProto(key) {
   var proto = {
     path_element: path
   };
-  if (namespace) {
+  if (key.namespace_) {
     proto.partition_id = {
-      namespace: namespace
+      namespace: key.namespace_
     };
   }
   return proto;

lib/datastore/index.js

@@ -36,18 +36,6 @@ var datastore = {};
  */
 datastore.Dataset = require('./dataset');
 
-/**
- * @borrows {module:datastore/entity~Key} as key
- *
- * @example
- * ```js
- * var key = dataset.key('Company', 123);
- * ```
- */
-datastore.key = function() {
-  return new entity.Key([].slice.call(arguments));
-};
-
 /**
  * @borrows {module:datastore/entity~Int} as int
  *

lib/datastore/query.js

@@ -14,6 +14,10 @@
  * limitations under the License.
  */
 
+/**
+ * @module datastore/query
+ */
+
 'use strict';
 
 var util = require('../common/util.js');
@@ -38,7 +42,7 @@ var util = require('../common/util.js');
  * ```
  */
 function Query(namespace, kinds) {
-  this.namespace = namespace;
+  this.namespace = namespace || null;
   this.kinds = kinds;
 
   this.filters = [];

lib/datastore/transaction.js

@@ -357,7 +357,7 @@ Transaction.prototype.delete = function(keys, callback) {
  * supported. If more results are available, a query to retrieve the next page
  * is provided to the callback function.
  *
- * @param {Query} query - Query object.
+ * @param {module:datastore/query} query - Query object.
  * @param {function} callback - The callback function.
  *
  * @example