private async Task GenerateErrorResponseAsync(HttpContext context, LuccaExceptionBuilderInfo info)
{
// Prepares the response request
ClearHttpResponseResponse(context, info.StatusCode);
// Extracts the Accept header
string acceptable = NegociateAcceptableContentType(context.Request);
if (acceptable != null)
{
if (await TryRenderErrorOnContentTypeAsync(acceptable, context, info))
{
return;
}
}
// If explicit content type (Content-Type header) match, we render
if (!string.IsNullOrEmpty(context.Request.ContentType) && await TryRenderErrorOnContentTypeAsync(context.Request.ContentType, context, info))
{
return;
}
// fallback on PreferedResponseType
if (!string.IsNullOrWhiteSpace(info.PreferedResponseType))
{
if (await TryRenderErrorOnContentTypeAsync(info.PreferedResponseType, context, info))
{
return;
}
}
// fallback on generic text/plain error
context.Response.ContentType = _textPlain;
await context.Response.WriteAsync(info.GenericErrorMessage);
}
private async Task JsonReport(HttpContext httpContext, LuccaExceptionBuilderInfo info)
{
string data = await _options.Value.JsonResponse(info);
httpContext.Response.ContentType = _appJson;
await httpContext.Response.WriteAsync(data);
}
public async Task Invoke(HttpContext context)
{
try
{
await _next(context);
}
catch (Exception ex)
{
_logger.LogError(0, ex, "An unhandled exception has occurred: " + ex.Message);
if (context.Response.HasStarted)
{
_logger.LogWarning("The response has already started, the error handler will not be executed.");
throw;
}
PathString originalPath = context.Request.Path;
try
{
var info = new LuccaExceptionBuilderInfo(ex,
_filter?.StatusCode(ex) ?? HttpStatusCode.InternalServerError,
_filter?.DisplayExceptionDetails(ex) ?? false,
_filter?.GenericErrorMessage,
_filter?.PreferedResponseType(context.Request.Path));
await GenerateErrorResponseAsync(context, info);
}
catch (Exception ex2)
{
_logger.LogError(0, ex2, "An exception was thrown attempting to execute the error handler.");
throw;
}
finally
{
context.Request.Path = originalPath;
}
}
}
private async Task <bool> TryRenderErrorOnContentTypeAsync(string contentType, HttpContext context, LuccaExceptionBuilderInfo info)
{
try
{
switch (contentType)
{
case _textPlain:
await TextPlainReport(context, info);
return(true);
case _appJson:
await JsonReport(context, info);
return(true);
case _textHtml:
await HtmlReport(context, info);
return(true);
}
}
catch (Exception e)
{
_logger.LogError(0, e, "An exception was thrown attempting to render the error with content type " + contentType);
}
return(false);
}
public Task <String> DefaultHandler(LuccaExceptionBuilderInfo builderInfo) => Task.FromResult($"Error code: {builderInfo.StatusCode}");
