private static IWebCrawler GetCustomBehaviorUsingLambdaWebCrawler()
{
IWebCrawler crawler = new PoliteWebCrawler();
crawler.ShouldCrawlPage((pageToCrawl, crawlContext) =>
{
return(new CrawlDecision {
Allow =
(pageToCrawl.Uri.AbsoluteUri.StartsWith("https://home.treasury.gov") ||
pageToCrawl.Uri.AbsoluteUri.StartsWith("https://www.treasury.gov")) &&
!pageToCrawl.Uri.AbsoluteUri.EndsWith(".pdf")
});
});
crawler.ShouldDownloadPageContent((crawledPage, crawlContext) =>
{
return(new CrawlDecision {
Allow = true
});
});
//Register a lambda expression that will tell Abot to not crawl links on any page that is not internal to the root uri.
//NOTE: This lambda is run after the regular ICrawlDecsionMaker.ShouldCrawlPageLinks method is run
crawler.ShouldCrawlPageLinks((crawledPage, crawlContext) =>
{
return(new CrawlDecision {
Allow = true
});
});
return(crawler);
}
public PoliteWebCrawler CreateCrawler()
{
_dataFinder = new DataFinder(new KomputronikDataExtractor());
XmlConfigurator.Configure();
CrawlConfiguration crawlConfig = AbotConfigurationSectionHandler.LoadFromXml().Convert();
crawlConfig.MaxConcurrentThreads = 15;//this overrides the config value
crawlConfig.MaxCrawlDepth = 15;
//Will use app.config for configuration
PoliteWebCrawler crawler = new PoliteWebCrawler();
crawler.ShouldCrawlPage(ShouldCrawlPage);
crawler.ShouldDownloadPageContent(ShouldCrawlPageContent);
crawler.ShouldCrawlPageLinks(ShouldCrawlPageLinks);
crawler.PageCrawlCompletedAsync += crawler_ProcessPageCrawlCompleted;
crawler.PageCrawlDisallowedAsync += crawler_PageCrawlDisallowed;
crawler.PageLinksCrawlDisallowedAsync += crawler_PageLinksCrawlDisallowed;
return(crawler);
}
private void ConfigureWebCrawler()
{
CrawlConfiguration config = new CrawlConfiguration();
config.MaxConcurrentThreads = Environment.ProcessorCount;
config.MaxPagesToCrawl = 0;
config.MaxPagesToCrawlPerDomain = 0;
config.MaxPageSizeInBytes = 0;
config.UserAgentString = "Mozilla/5.0 (Windows NT 6.3; Trident/7.0; rv:11.0) like Gecko";
config.HttpProtocolVersion = HttpProtocolVersion.NotSpecified;
config.CrawlTimeoutSeconds = 0;
config.IsUriRecrawlingEnabled = false;
config.IsExternalPageCrawlingEnabled = false;
config.IsExternalPageLinksCrawlingEnabled = false;
config.IsRespectUrlNamedAnchorOrHashbangEnabled = false;
config.DownloadableContentTypes = "text/html, text/plain";
config.HttpServicePointConnectionLimit = 200;
config.HttpRequestTimeoutInSeconds = 15;
config.HttpRequestMaxAutoRedirects = 7;
config.IsHttpRequestAutoRedirectsEnabled = true;
config.IsHttpRequestAutomaticDecompressionEnabled = true;
config.IsSendingCookiesEnabled = false;
config.IsSslCertificateValidationEnabled = false;
config.MinAvailableMemoryRequiredInMb = 0;
config.MaxMemoryUsageInMb = 0;
config.MaxMemoryUsageCacheTimeInSeconds = 0;
config.MaxCrawlDepth = 1000;
config.MaxLinksPerPage = 1000;
config.IsForcedLinkParsingEnabled = false;
config.MaxRetryCount = 0;
config.MinRetryDelayInMilliseconds = 0;
config.IsRespectRobotsDotTextEnabled = true;
config.UrlPatternsToExclude = ExtractorParams.UrlPatternsToExclude;
config.IsRespectMetaRobotsNoFollowEnabled = true;
config.IsRespectHttpXRobotsTagHeaderNoFollowEnabled = true;
config.IsRespectAnchorRelNoFollowEnabled = true;
config.IsIgnoreRobotsDotTextIfRootDisallowedEnabled = false;
config.RobotsDotTextUserAgentString = "bingbot";
config.MinCrawlDelayPerDomainMilliSeconds = ExtractorParams.MinCrawlDelay;
config.MaxRobotsDotTextCrawlDelayInSeconds = 5;
config.IsAlwaysLogin = false;
config.LoginUser = "";
config.LoginPassword = "";
config.UseDefaultCredentials = false;
if (!DoContinue)
{
scheduler = new Scheduler(config.IsUriRecrawlingEnabled, null, null);
}
else
{
using (FileStream fs = new FileStream(Path.Combine(ContentDirectory.FullName, LogsDirName, CheckpointFileName), FileMode.Open))
{
scheduler = Scheduler.Deserialize(fs);
}
}
crawler = new PoliteWebCrawler(config, null, null, scheduler, null, null, null, null, null);
crawler.IsInternalUri((candidateUri, rootUri) => HtmlFileUtils.ShouldCrawlUri(ExtractorParams.Scope, candidateUri, rootUri));
crawler.ShouldCrawlPageLinks(WebCrawler_ShouldCrawlPageLinks);
crawler.PageCrawlCompletedAsync += WebCrawler_PageCrawlCompletedAsync;
// DEBUG: uncomment to debug Abot crawl progress
// crawler.PageCrawlStartingAsync += WebCrawler_PageCrawlStartingAsync;
// DEBUG: uncomment to debug Abot crawling decisions
// crawler.PageCrawlDisallowedAsync += WebCrawler_PageCrawlDisallowedAsync;
// crawler.PageLinksCrawlDisallowedAsync += WebCrawler_PageLinksCrawlDisallowedAsync;
}