Refactor print preview web ui

chrome/browser/resources/print_preview/cloud_print_interface.js

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+cr.define('cloudprint', function() {
+  'use strict';
+
+  /**
+   * API to the Google Cloud Print service.
+   * @param {string} baseUrl Base part of the Google Cloud Print service URL
+   *     with no trailing slash. For example,
+   *     'https://www.google.com/cloudprint'.
+   * @constructor
+   * @extends {cr.EventTarget}
+   */
+  function CloudPrintInterface(baseUrl) {
+    /**
+     * The base URL of the Google Cloud Print API.
+     * @type {string}
+     * @private
+     */
+    this.baseURL_ = baseUrl;
+
+    /**
+     * Last received XSRF token. Sent as a parameter in every request.
+     * @type {string}
+     * @private
+     */
+    this.xsrfToken_ = '';
+  };
+
+  /**
+   * Event types dispatched by the interface.
+   * @enum {string}
+   */
+  CloudPrintInterface.EventType = {
+    ERROR: 'cloudprint.CloudPrintInterface.ERROR',
+    PRINTER_DONE: 'cloudprint.CloudPrintInterface.PRINTER_DONE',
+    SEARCH_DONE: 'cloudprint.CloudPrintInterface.SEARCH_DONE',
+    SUBMIT_DONE: 'cloudprint.CloudPrintInterface.SUBMIT_DONE'
+  };
+
+  /**
+   * Content type header value for a URL encoded HTTP request.
+   * @type {string}
+   * @private
+   */
+  CloudPrintInterface.URL_ENCODED_CONTENT_TYPE_ =
+      'application/x-www-form-urlencoded';
+
+  /**
+   * Content type header value for a multipart HTTP request.
+   * @type {string}
+   * @private
+   */
+  CloudPrintInterface.MULTIPART_CONTENT_TYPE_ =
+      'multipart/form-data; boundary=----CloudPrintFormBoundaryjc9wuprokl8i';
+
+  /**
+   * Enumeration of JSON response fields from Google Cloud Print API.
+   * @enum {string}
+   * @private
+   */
+  CloudPrintInterface.JsonFields_ = {
+    PRINTER: 'printer'
+  };
+
+  CloudPrintInterface.prototype = {
+    __proto__: cr.EventTarget.prototype,
+
+    /**
+     * Sends a Google Cloud Print search API request.
+     * @param {boolean} isRecent Whether to search for only recently used
+     *     printers.
+     */
+    search: function(isRecent) {
+      var params = {};
+      if (isRecent) {
+        params['q'] = '^recent';
+      }
+      this.sendRequest_('GET', 'search', params, null, this.onSearchDone_);
+    },
+
+    /**
+     * Sends a Google Cloud Print submit API request.
+     * @param {string} body Body of the HTTP post request to send.
+     */
+    submit: function(body) {
+      this.sendRequest_('POST', 'submit', null, body, this.onSubmitDone_);
+    },
+
+    /**
+     * Sends a Google Cloud Print printer API request.
+     * @param {string} printerId ID of the printer to lookup.
+     */
+    printer: function(printerId) {
+      var params = {'printerid': printerId};

[kmadhusu, 2012/05/18 20:13:46]

nit: single quote is not required.

+      this.sendRequest_('GET', 'printer', params, null, this.onPrinterDone_);
+    },
+
+    /**
+     * Creates an object that represents a Google Cloud Print print ticket.
+     * @param {!print_preview.Destination} destination Destination to print to.
+     * @param {!print_preview.PrintTicketStore} printTicketStore Used to create
+     *     the state of the print ticket.
+     * @return {object} Google Cloud Print print ticket.
+     */
+    createPrintTicket: function(destination, printTicketStore) {
+      if (destination.isLocal) {
+        throw Error(

[kmadhusu, 2012/05/18 20:13:46]

throw Error ()...  => logError(msg)?

+            'Trying to create a Google Cloud Print print ticket for a local ' +
+            'destination');
+      }
+      if (!destination.capabilities) {
+        throw Error(
+            'Trying to create a Google Cloud Print print ticket for a ' +
+            'destination with no print capabilities');
+      }
+
+      var ticketItems = [];
+
+      if (destination.capabilities.collateCapability) {
+        var collateCap = destination.capabilities.collateCapability;
+        var ticketItem = {
+          'name': collateCap.id,
+          'type': collateCap.type,
+          'options': [{'name': printTicketStore.isCollateEnabled() ?
+              collateCap.collateOption : collateCap.noCollateOption}]
+        };
+        ticketItems.push(ticketItem);
+      }
+
+      if (destination.capabilities.colorCapability) {
+        var colorCap = destination.capabilities.colorCapability;
+        var ticketItem = {
+          'name': colorCap.id,
+          'type': colorCap.type,
+          'options': [{'name': printTicketStore.isColorEnabled() ?
+              colorCap.colorOption : colorCap.bwOption}]
+        };
+        ticketItems.push(ticketItem);
+      }
+
+      if (destination.capabilities.copiesCapability) {
+        var copiesCap = destination.capabilities.copiesCapability;
+        var ticketItem = {
+          'name': copiesCap.id,
+          'type': copiesCap.type,
+          'value': printTicketStore.getCopies()
+        };
+        ticketItems.push(ticketItem);
+      }
+
+      if (destination.capabilities.duplexCapability) {
+        var duplexCap = destination.capabilities.duplexCapability;
+        var ticketItem = {
+          'name': duplexCap.id,
+          'type': duplexCap.type,
+          'options': [{'name': printTicketStore.isDuplexEnabled() ?
+              duplexCap.longEdgeOption : duplexCap.simplexOption}]
+        };
+        ticketItems.push(ticketItem);
+      }
+
+      return {
+        'capabilities': ticketItems
+      };
+    },
+
+    /**
+     * Sends a request to the Google Cloud Print API.
+     * @param {string} method HTTP method of the request.
+     * @param {string} action Google Cloud Print action to perform.
+     * @param {Object} params HTTP parameters to include in the request.
+     * @param {string} body HTTP multi-part encoded body.
+     * @param {function(Object)} successCallback Callback to invoke when request
+     *     completes successfully.
+     */
+    sendRequest_: function(method, action, params, body, successCallback) {
+      if (!this.xsrfToken_) {
+        // TODO Should throw an error if not a read-only action or issue an
+        // xsrf token request.
+      }
+      var url = this.baseURL_ + '/' + action + '?xsrf=' + this.xsrfToken_;
+
+      if (params) {
+        for (var paramName in params) {
+          url += '&' + paramName + '=' + encodeURIComponent(params[paramName]);
+        }
+      }
+
+      var headers = {};
+      headers['X-CloudPrint-Proxy'] = 'ChromePrintPreview';
+      if (method == 'GET') {
+        headers['Content-Type'] = CloudPrintInterface.URL_ENCODED_CONTENT_TYPE_;
+      } else if (method == 'POST') {
+        headers['Content-Type'] = CloudPrintInterface.MULTIPART_CONTENT_TYPE_;
+      }
+
+      var xhr = new XMLHttpRequest();
+      xhr.onreadystatechange = this.onReadyStateChange_.bind(
+          this, xhr, successCallback.bind(this));
+      xhr.open(method, url, true);
+      xhr.withCredentials = true;
+      for (var header in headers) {
+        xhr.setRequestHeader(header, headers[header]);
+      }
+      xhr.send(body);
+    },
+
+    /**
+     * Dispatches an ERROR event with the given error message.
+     * @param {string} message Error message to include in the ERROR event.
+     * @private
+     */
+    dispatchErrorEvent_: function(message) {
+      var errorEvent = new cr.Event(CloudPrintInterface.EventType.ERROR);
+      errorEvent.message = message;
+      this.dispatchEvent(errorEvent);
+    },
+
+    /**
+     * Called when the ready-state of a XML http request changes.
+     * Calls the successCallback with the result or dispatches an ERROR event.
+     * @param {XMLHttpRequest} xhr XML http request that changed.
+     * @param {function(Object)} successCallback Callback to call if the request
+     *     was successful.
+     * @private
+     */
+    onReadyStateChange_: function(xhr, successCallback) {
+      if (xhr.readyState == 4) {
+        if (xhr.status == 200) {
+          var result = JSON.parse(xhr.responseText);
+          if (result['success']) {
+            this.xsrfToken_ = result['xsrf_token'];
+            successCallback(result);
+          } else {
+            this.dispatchErrorEvent_(result['message']);
+          }
+        } else {
+          this.dispatchErrorEvent_(xhr.status + '');
+        }
+      }
+    },
+
+    /**
+     * Called when the search request completes successfully.
+     * @param {Object} result JSON response.
+     * @private
+     */
+    onSearchDone_: function(result) {
+      var printerListJson = result['printers'] || [];
+      var printerList = [];
+      for (var printerJson, i = 0; printerJson = printerListJson[i]; i++) {
+        try {
+          printerList.push(cloudprint.CloudDestinationParser.parse(
+              printerJson));
+        } catch (err) {
+          logError('Unable to parse cloud print destination: ' + err);
+        }
+      }
+      var isRecent = result['request']['params']['q'] == '^recent';
+      var searchDoneEvent =
+          new cr.Event(CloudPrintInterface.EventType.SEARCH_DONE);
+      searchDoneEvent.printers = printerList;
+      searchDoneEvent.isRecent = isRecent;
+      searchDoneEvent.email = result['request']['user'];
+      this.dispatchEvent(searchDoneEvent);
+    },
+
+    /**
+     * Called when the submit request completes successfully.
+     * @param {Object} result JSON response.
+     * @private
+     */
+    onSubmitDone_: function(result) {
+      this.dispatchEvent(
+          new cr.Event(CloudPrintInterface.EventType.SUBMIT_DONE));
+    },
+
+    /**
+     * Called when the printer request completes successfully.
+     * @param {Object} result JSON response.
+     * @private
+     */
+    onPrinterDone_: function(result) {
+      // TODO Better error handling here.
+      var printerJson = result['printers'][0];
+      var printer;
+      try {
+        printer = cloudprint.CloudDestinationParser.parse(printerJson);
+      } catch (err) {
+        throw Error('Failed to parse cloud print destination: ' +
+            JSON.stringify(printerJson));
+        return;
+      }
+      var printerDoneEvent = new cr.Event(
+          CloudPrintInterface.EventType.PRINTER_DONE);
+      printerDoneEvent.printer = printer;
+      this.dispatchEvent(printerDoneEvent);
+    }
+  };
+
+  // Export
+  return {
+    CloudPrintInterface: CloudPrintInterface
+  };
+});