Implement Service & ServiceObject classes

Author: stephenplusplus

lib/common/service-object.js

@@ -0,0 +1,303 @@
+/*!
+ * Copyright 2015 Google Inc. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*!
+ * @module common/serviceObject
+ */
+
+'use strict';
+
+var exec = require('methmeth');
+var is = require('is');
+
+/**
+ * @type {module:common/util}
+ * @private
+ */
+var util = require('./util.js');
+
+/**
+ * ServiceObject is a base class, meant to be inherited from by a "service
+ * object," like a BigQuery dataset or Storage bucket.
+ *
+ * Most of the time, these objects share common functionality; they can be
+ * created or deleted, and you can get or set their metadata.
+ *
+ * By inheriting from this class, a service object will be extended with these
+ * shared behaviors. Note that any method can be overridden when the service
+ * object requires specific behavior.
+ *
+ * @private
+ *
+ * @param {object} config - Configuration object.
+ * @param {string} config.baseUrl - The base URL to make API requests to.
+ * @param {string} config.createMethod - The method which creates this object.
+ * @param {string} config.id - The identifier of the object. For example, the
+ *     name of a Storage bucket or Pub/Sub topic.
+ * @param {object=} config.methods - A map of each method name that should be
+ *     inherited.
+ * @param {object} config.parent - The parent service instance. For example, an
+ *     instance of Storage if the object is Bucket.
+ */
+function ServiceObject(config) {
+  var self = this;
+
+  this.metadata = {};
+
+  this.baseUrl = config.baseUrl;
+  this.parent = config.parent; // Parent class.
+  this.id = config.id; // Name or ID (e.g. dataset ID, bucket name, etc.)
+  this.createMethod = config.createMethod;
+
+  if (config.methods) {
+    var allMethodNames = Object.keys(ServiceObject.prototype);
+    allMethodNames
+      .filter(function(methodName) {
+        return (
+          // All ServiceObjects need `request`.
+          methodName !== 'request' &&
+
+          // The ServiceObject didn't redefine the method.
+          self[methodName] === ServiceObject.prototype[methodName] &&
+
+          // This method isn't wanted.
+          !config.methods[methodName]
+        );
+      })
+      .forEach(function(methodName) {
+        self[methodName] = undefined;
+      });
+  }
+}
+
+/**
+ * Create the object.
+ *
+ * @param {object=} options - Configuration object.
+ * @param {function=} callback - The callback function.
+ * @param {?error} callback.err - An error returned while making this request.
+ * @param {object} callback.instance - The instance.
+ * @param {object} callback.apiResponse - The full API response.
+ */
+ServiceObject.prototype.create = function(options, callback) {
+  var self = this;
+  var args = [this.id];
+
+  if (is.fn(options)) {
+    callback = options;
+  }
+
+  if (is.object(options)) {
+    args.push(options);
+  }
+
+  // Wrap the callback to return *this* instance of the object, not the newly-
+  // created one.
+  function onCreate(err, instance, apiResponse) {
+    if (err) {
+      callback(err, null, apiResponse);
+      return;
+    }
+
+    self.metadata = instance.metadata;
+
+    callback(null, self, apiResponse);
+  }
+
+  args.push(onCreate);
+
+  this.createMethod.apply(null, args);
+};
+
+/**
+ * Delete the object.
+ *
+ * @param {function=} callback - The callback function.
+ * @param {?error} callback.err - An error returned while making this request.
+ * @param {object} callback.apiResponse - The full API response.
+ */
+ServiceObject.prototype.delete = function(callback) {
+  var reqOpts = {
+    method: 'DELETE',
+    uri: ''
+  };
+
+  // The `request` method may have been overridden to hold any special behavior.
+  // Ensure we call the original `request` method.
+  ServiceObject.prototype.request.call(this, reqOpts, function(err, resp) {
+    callback(err, resp);
+  });
+};
+
+/**
+ * Check if the object exists.
+ *
+ * @param {function} callback - The callback function.
+ * @param {?error} callback.err - An error returned while making this request.
+ * @param {boolean} callback.exists - Whether the object exists or not.
+ */
+ServiceObject.prototype.exists = function(callback) {
+  this.get(function(err) {
+    if (err) {
+      if (err.code === 404) {
+        callback(null, false);
+      } else {
+        callback(err);
+      }
+
+      return;
+    }
+
+    callback(null, false);
+  });
+};
+
+/**
+ * Get the object if it exists. Optionally have the object created if an options
+ * object is provided with `autoCreate: true`.
+ *
+ * @param {object=} config - The configuration object that will be used to
+ *     create the object if necessary.
+ * @param {boolean} config.autoCreate - Create the object if it doesn't already
+ *     exist.
+ * @param {function} callback - The callback function.
+ * @param {?error} callback.err - An error returned while making this request.
+ * @param {object} callback.instance - The instance.
+ * @param {object} callback.apiResponse - The full API response.
+ */
+ServiceObject.prototype.get = function(config, callback) {
+  var self = this;
+
+  if (is.fn(config)) {
+    callback = config;
+    config = {};
+  }
+
+  config = config || {};
+
+  var autoCreate = config.autoCreate && is.fn(this.create);
+  delete config.autoCreate;
+
+  this.getMetadata(function(err, metadata) {
+    if (err) {
+      if (err.code === 404 && autoCreate) {
+        if (!is.empty(config)) {
+          self.create(config, callback);
+        } else {
+          self.create(callback);
+        }
+        return;
+      }
+
+      callback(err, null, metadata);
+      return;
+    }
+
+    callback(null, self, metadata);
+  });
+};
+
+/**
+ * Get the metadata of this object.
+ *
+ * @param {function} callback - The callback function.
+ * @param {?error} callback.err - An error returned while making this request.
+ * @param {object} callback.metadata - The metadata for this object.
+ * @param {object} callback.apiResponse - The full API response.
+ */
+ServiceObject.prototype.getMetadata = function(callback) {
+  var self = this;
+
+  var reqOpts = {
+    uri: ''
+  };
+
+  // The `request` method may have been overridden to hold any special behavior.
+  // Ensure we call the original `request` method.
+  ServiceObject.prototype.request.call(this, reqOpts, function(err, resp) {
+    if (err) {
+      callback(err, null, resp);
+      return;
+    }
+
+    self.metadata = resp;
+
+    callback(null, self.metadata, resp);
+  });
+};
+
+/**
+ * Set the metadata for this object.
+ *
+ * @param {object} metadata - The metadata to set on this object.
+ * @param {function=} callback - The callback function.
+ * @param {?error} callback.err - An error returned while making this request.
+ * @param {object} callback.instance - The instance.
+ * @param {object} callback.apiResponse - The full API response.
+ */
+ServiceObject.prototype.setMetadata = function(metadata, callback) {
+  var self = this;
+
+  callback = callback || util.noop;
+
+  var reqOpts = {
+    method: 'PATCH',
+    uri: '',
+    json: metadata
+  };
+
+  // The `request` method may have been overridden to hold any special behavior.
+  // Ensure we call the original `request` method.
+  ServiceObject.prototype.request.call(this, reqOpts, function(err, resp) {
+    if (err) {
+      callback(err, resp);
+      return;
+    }
+
+    self.metadata = resp;
+
+    callback(null, resp);
+  });
+};
+
+/**
+ * Make an authenticated API request.
+ *
+ * @private
+ *
+ * @param {object} reqOpts - Request options that are passed to `request`.
+ * @param {string} reqOpts.uri - A URI relative to the baseUrl.
+ * @param {function} callback - The callback function passed to `request`.
+ */
+ServiceObject.prototype.request = function(reqOpts, callback) {
+  var uriComponents = [
+    this.baseUrl,
+    this.id,
+    reqOpts.uri
+  ];
+
+  reqOpts.uri = uriComponents
+    .filter(exec('trim')) // Limit to non-empty strings.
+    .map(function(uriComponent) {
+      var trimSlashesRegex = /^\/*|\/*$/g;
+      return uriComponent.replace(trimSlashesRegex, '');
+    })
+    .join('/');
+
+  this.parent.request(reqOpts, callback);
+};
+
+module.exports = ServiceObject;

lib/common/service.js

@@ -0,0 +1,90 @@
+/*!
+ * Copyright 2015 Google Inc. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*!
+ * @module common/service
+ */
+
+'use strict';
+
+/**
+ * @type {module:common/util}
+ * @private
+ */
+var util = require('./util.js');
+
+/**
+ * Service is a base class, meant to be inherited from by a "service," like
+ * BigQuery or Storage.
+ *
+ * This handles making authenticated requests by exposing a `makeReq_` function.
+ *
+ * @param {object} config - Configuration object.
+ * @param {string} config.baseUrl - The base URL to make API requests to.
+ * @param {string[]} config.scopes - The scopes required for the request.
+ * @param {object} options - [Configuration object](#/docs/?method=gcloud).
+ */
+function Service(config, options) {
+  this.makeAuthenticatedRequest = util.makeAuthenticatedRequestFactory({
+    scopes: config.scopes,
+    credentials: options.credentials,
+    keyFile: options.keyFilename,
+    email: options.email
+  });
+
+  this.authClient = this.makeAuthenticatedRequest.authClient;
+  this.baseUrl = config.baseUrl;
+  this.getCredentials = this.makeAuthenticatedRequest.getCredentials;
+  this.projectId = options.projectId;
+  this.projectIdRequired = config.projectIdRequired !== false;
+}
+
+/**
+ * Make an authenticated API request.
+ *
+ * @private
+ *
+ * @param {object} reqOpts - Request options that are passed to `request`.
+ * @param {string} reqOpts.uri - A URI relative to the baseUrl.
+ * @param {function} callback - The callback function passed to `request`.
+ */
+Service.prototype.request = function(reqOpts, callback) {
+  var uriComponents = [
+    this.baseUrl
+  ];
+
+  if (this.projectIdRequired) {
+    uriComponents.push('projects');
+    uriComponents.push(this.projectId);
+  }
+
+  uriComponents.push(reqOpts.uri);
+
+  reqOpts.uri = uriComponents
+    .map(function(uriComponent) {
+      var trimSlashesRegex = /^\/*|\/*$/g;
+      return uriComponent.replace(trimSlashesRegex, '');
+    })
+    .join('/')
+    // Some URIs have colon separators.
+    // Bad: https://.../projects/:list
+    // Good: https://.../projects:list
+    .replace(/\/:/g, ':');
+
+  this.makeAuthenticatedRequest(reqOpts, callback);
+};
+
+module.exports = Service;