Initial commit for Chrome metainstaller on Mac.

chrome/installer/mac/app/parser.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 "parser.h"
+
+@implementation Parser
+
+- (id)initWithXML:(NSData*)omahaResponseXML{
+  if ((self = [super init])) {
+    omahaResponseXML_ = omahaResponseXML;
+  }
+  return self;
+}
+
+- (NSMutableArray*)chromeIncompleteDownloadURLs{
+  return chromeIncompleteDownloadURLs_;
+}
+
+- (NSString*)chromeImageFilename{
+  return chromeImageFilename_;
+}
+
+// Sets up instance of NSXMLParser and calls on delegate methods to do actual
+// parsing work.
+- (void)parseXML{
+  if (omahaResponseXML_) {
+    NSXMLParser* parser = [[NSXMLParser alloc] initWithData:omahaResponseXML_];
+    [parser setDelegate:self];
+    [parser parse];
+  } else {
+  // TODO: error handler
+  }
+}
+
+// Method implementation for XMLParserDelegate.
+// Searches the XML data for the tag "URL" and the subsequent "codebase"
+// attribute that indicates a URL follows. Copies each URL into an array.
+// Note that the URLs in the XML file are incomplete. They need the filename
+// appended to end. The second if statement checks for the tag "package" which
+// contains the filename we need to complete the URLs.
+- (void)parser:(NSXMLParser*)parser
+didStartElement:(NSString*)elementName
+  namespaceURI:(NSString*)namespaceURI
+ qualifiedName:(NSString*)qName
+    attributes:(NSDictionary*)attributeDict {
+  if ([elementName isEqualToString:@"url"]) {
+    if (!chromeIncompleteDownloadURLs_) {
+      chromeIncompleteDownloadURLs_ = [[NSMutableArray alloc] init];
+    }
+    NSString* extractedURL = [attributeDict objectForKey:@"codebase"];
+    [chromeIncompleteDownloadURLs_ addObject: extractedURL];
+  }
+  if ([elementName isEqualToString:@"package"]) {
+    chromeImageFilename_ = [[NSString alloc] initWithFormat:@"%@",
+                            [attributeDict objectForKey:@"name"]];
+  }
+}
+
+@end