public void Setup()
{
outStream = new MemoryStream();
elements = new StreamedElements();
testStreamer = null;
}
private void ConfigureJsonFileWriter()
{
// 1. Identify the elements, and their types.
var elements = new StreamedElements();
// I want to be able to intercept a Base64 encoded element and string property
elements.Add(Constants.DocumentJsonPath, new Base64ToTempFileWriter());
elements.Add(Constants.FilenameJsonPath, new StringValueStreamWriter());
// Specify when to use this Context
var jsonEndpoints = new List <string>()
{
"/api/document/upload"
};
var jsonContentTypes = new List <string>()
{
"application/json", "application/json;charset=utf-8"
};
// Now plug in a Element Streamer.
var elementStreamer = new JsonElementStreamer(elements);
var jsonRequestContext = new ElementStreamingRequestContext(jsonEndpoints, jsonContentTypes, elements, elementStreamer);
// Finally add what we new want to do when we receive data (use a lambda or specific funciton).
jsonRequestContext.OnElementStarting = s => true; // do nothing for starting
jsonRequestContext.OnElementCompleted = s =>
{
var handled = false;
var docElement = s.GetElement(Constants.DocumentJsonPath);
if (docElement != null && s.Streamer.ElementPath == Constants.DocumentJsonPath && docElement.IsComplete)
{
//Add a new context element indicating the size of the stream.
var fileSize = docElement.OutStream.Length;
var tmpFileName = docElement.TypedValue.AsString();
if (fileSize > 0) // check for the null case
{
var sizeElement = new DynamicValueStreamWriter(docElement.OutStream.Length.ToString());
s.Elements.Add(Constants.ByteSizeJsonPath, sizeElement);
// substitute the original base64 code with the filename:
var newFilenameElement = new DynamicValueStreamWriter(tmpFileName);
s.Elements.Add(Constants.TempFileJsonPath, newFilenameElement);
//warning: this will write synchronously
s.Streamer.WriteAlternateContent(tmpFileName);
// and now get rid of that streamer - as we now have a file reference.
s.Elements.DiscardElement(Constants.DocumentJsonPath);
}
else
{
docElement.Ignore = true;
docElement.OutStream.Dispose();
}
// was this a file we previously decided to discard?
if (docElement.Ignore)
{
if (File.Exists(tmpFileName))
{
File.Delete(tmpFileName);
}
}
handled = true;
}
else
{
// Check for unwanted file types we need to delete or block.
var fnameElement = s.GetElement(Constants.FilenameJsonPath);
var newFilenameElement = s.GetElement(Constants.TempFileJsonPath);
if (s.Streamer.ElementPath == Constants.FilenameJsonPath && fnameElement.IsComplete)
{
var fname = fnameElement.TypedValue.AsString();
var extn = Path.GetExtension(fname);
var blockedTypes = new List <string>()
{
".exe", ".svg", ".dll", ".bat", ".com", ".sh", ".ps1"
};
var blockFile = blockedTypes.Any(t => t.ToLower() == extn);
if (docElement != null)
{
// encounterd FileName first - so we can block the file from being written
docElement.Ignore = blockFile;
}
if (newFilenameElement != null)
{
var tmpFileName = newFilenameElement.TypedValue.AsString();
// we have already written it, delete it now.
if (File.Exists(tmpFileName))
{
File.Delete(tmpFileName);
}
}
handled = true;
}
}
return(handled);
};
this.ElementStreamingRequestContexts.Add(jsonRequestContext);
}
