Initial commit for Chrome metainstaller on Mac.

chrome/installer/mac/app/downloader.m

+// Copyright 2016 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.
+
+#import <Foundation/Foundation.h>
+#import "downloader.h"
+#import "parser.h"
+#import "NetworkCommunication.h"
+#import "delegate.h"
+
+@implementation Downloader
+
+// The URLs extracted from parseXML are incomplete and need the filename (which
+// is the same for all the links) appended to the end. Iterates through
+// chromeIncompleteDownloadURLs_ and appends chromeImageFilename_ to each URL.
+- (NSMutableArray*)appendFilename:(NSString*)filename
+                           toURLs:(NSArray*)incompleteURLs {
+  NSMutableArray* completeURLs = [[NSMutableArray alloc] init];
+
+  for (NSString* URL in incompleteURLs) {
+    [completeURLs addObject: [NSString stringWithFormat:@"%@%@",URL,filename]];

[Elly Fong-Jones, 2016/07/06 15:22:02]

no space after : (in the rest of this file, too)

+  }
+  return completeURLs;
+}
+
+// Calls parseXML to extract URLs and the filename. Then calls appenFilename to

[Elly Fong-Jones, 2016/07/06 15:22:02]

It's better for the comment to describe what the function does, not how it does
it. You can tell from looking at the code that it calls parseXML and then
appendFilename.

+// complete the URLs and returns the first complete URL.
+- (NSURL*)parseOhamaResponseForChromeImageURLAndFilename:(NSData*)omahaResponseXML {

[Elly Fong-Jones, 2016/07/06 15:22:02]

getChromeImageURLFromOmahaResponse:?

+  Parser* parser = [[Parser alloc] initWithXML: omahaResponseXML];
+  [parser parseXML];
+
+  NSMutableArray* completeURLs =
+      [self appendFilename:parser.chromeImageFilename
+                    toURLs:parser.chromeIncompleteDownloadURLs];
+  // TODO: Error handling and implement way to verify URL is working
+  if(!completeURLs || [completeURLs count] < 1) {
+    NSLog(@"There were no download links found.");
+    return nil;
+  }
+  NSString* chromeURLString = [completeURLs firstObject];
+  return [NSURL URLWithString:chromeURLString];
+}
+
+// Downloads contents of chromeURL to downloads folders and delegates the work
+// to the DownloadDelegate class.
+- (void)writeChromeImageToDownloadsDirectory:(NSURL*)chromeURL {
+  DownloadDelegate *delegate = [[DownloadDelegate alloc] init];
+  NetworkCommunication* downloadTask = [[NetworkCommunication alloc]
+                                        initWithDelegate: delegate];
+
+  // TODO: What if file already exists?
+  [downloadTask createRequestWithURLasString:[NSString
+    stringWithFormat:@"%@",chromeURL] andXMLBody: nil];
+  [downloadTask sendDownloadRequest];
+
+  NSLog(@"File was downloaded to Downloads.");
+}
+
+// Pieces together the getting the URL portion and downloading the contents of
+// URL portion.
+- (void)downloadChromeImageToDownloadsDirectory: (NSData*)responseXMLData {
+  NSURL* chromeURL = [self
+    parseOhamaResponseForChromeImageURLAndFilename: responseXMLData];
+  [self writeChromeImageToDownloadsDirectory: chromeURL];
+}
+
+@end