private void LoadAndExecute(string scraper, CancellationToken cancelationToken)
{
var context = new ScraperLoadContext();
try
{
_logger.LogInformation("Starting scraper {scraper}", scraper);
var path = Path.Combine(Directory.GetCurrentDirectory(), "Scrapers", $"{scraper}.dll");
var assembly = context.LoadFromAssemblyPath(path);
var type = assembly.GetType($"{scraper}.Scraper");
var method = type.GetMethod("ExecuteAsync");
var instance = ActivatorUtilities.CreateInstance(_serviceProvider, type);
_queue.ScraperStatusChanged(scraper, CurrentStatus.Running);
var task = (Task <ScrapingResult>)method.Invoke(instance, new object[] { _browserService.Browser, cancelationToken });
switch (task.Result)
{
case ScrapingResult.Success:
_queue.ScraperStatusChanged(scraper, CurrentStatus.Success);
break;
case ScrapingResult.Canceled:
_queue.ScraperStatusChanged(scraper, CurrentStatus.Canceled);
break;
case ScrapingResult.Error:
_queue.ScraperStatusChanged(scraper, CurrentStatus.Error);
break;
default:
_queue.ScraperStatusChanged(scraper, CurrentStatus.Unknown);
break;
}
_logger.LogInformation("Scraper {scraper} finished", scraper);
}
catch (Exception exc)
{
_queue.ScraperStatusChanged(scraper, CurrentStatus.Error);
_logger.LogError(exc, "Scraper {scraper} error", scraper);
}
//TODO: https://developercommunity.visualstudio.com/content/problem/785136/c-debugger-crashes-after-unloading-assemblyloadcon.html
context.Unload();
}
private ScraperValidateResult ValidateScraper(string path)
{
var result = new ScraperValidateResult
{
Parameters = new List <Parameter>()
};
var context = new ScraperLoadContext();
var assembly = context.LoadFromAssemblyPath(path);
var bytes = assembly.GetName().GetPublicKeyToken();
if (bytes != null && bytes.Length > 0)
{
var token = BitConverter.ToString(bytes).Replace("-", string.Empty).ToLower();
if (token == "b96cd5d24947157a")
{
var name = Path.GetFileNameWithoutExtension(path);
var type = assembly.GetType($"{name}.Scraper");
var instance = ActivatorUtilities.CreateInstance(_provider, type);
result.Description = type.GetProperty("Description").GetValue(instance, null).ToString();
var resourceNames = assembly.GetManifestResourceNames();
foreach (var rn in resourceNames)
{
using var stream = assembly.GetManifestResourceStream(rn);
using var reader = new StreamReader(stream, Encoding.UTF8);
result.Parameters.Add(new Parameter
{
Name = rn,
Value = reader.ReadToEnd()
});
}
result.Success = true;
}
}
context.Unload();
return(result);
}
