/// <summary>
/// Get a value indicating whether the request is made by search engine (web crawler)
/// </summary>
/// <returns>Result</returns>
public virtual bool IsSearchEngine()
{
if (_httpContextAccessor?.HttpContext == null)
{
return(false);
}
try
{
BrowscapXmlHelper browscapXmlHelper = GetBrowscapXmlHelper();
//we cannot load parser
if (browscapXmlHelper == null)
{
return(false);
}
Microsoft.Extensions.Primitives.StringValues userAgent = _httpContextAccessor.HttpContext.Request.Headers[HeaderNames.UserAgent];
return(!string.IsNullOrWhiteSpace(userAgent) && browscapXmlHelper.IsCrawler(userAgent));
}
catch
{
// ignored
}
return(false);
}
protected virtual BrowscapXmlHelper GetBrowscapXmlHelper()
{
if (Singleton <BrowscapXmlHelper> .Instance != null)
{
return(Singleton <BrowscapXmlHelper> .Instance);
}
string userAgentStringPath = "~/App_Data/browscap.xml";
//no database created
if (string.IsNullOrEmpty(userAgentStringPath))
{
return(null);
}
//prevent multi loading data
lock (_locker)
{
//data can be loaded while we waited
if (Singleton <BrowscapXmlHelper> .Instance != null)
{
return(Singleton <BrowscapXmlHelper> .Instance);
}
string userAgentStringsPath = _fileProvider.MapPath(userAgentStringPath);
string crawlerOnlyUserAgentStringsPath = _fileProvider.MapPath("~/App_Data/browscap.crawlersonly.xml");
BrowscapXmlHelper browscapXmlHelper = new BrowscapXmlHelper(userAgentStringsPath, crawlerOnlyUserAgentStringsPath, _fileProvider);
Singleton <BrowscapXmlHelper> .Instance = browscapXmlHelper;
return(Singleton <BrowscapXmlHelper> .Instance);
}
}
