DocumentMimeTypes Class (original) (raw)
Summary
MIME type whitelisting support.
Syntax
public class DocumentMimeTypes public:
ref class DocumentMimeTypes
Example
This example will allow only loading PDF and TIFF documents and deny everything else. The example also installs a callback to log all the MIME type verification operations. The user callback can return any value for the status of the MIME type or call GetDocumentStatus to continue with the configured action.
using Leadtools;
using Leadtools.Codecs;
using Leadtools.Document.Writer;
using Leadtools.Document;
using Leadtools.Caching;
using Leadtools.Annotations.Engine;
using Leadtools.Ocr;
using Leadtools.Barcode;
using Leadtools.Document.Converter;
public void MimeTypesWhitelistExample()
{
// Documents to try and load
string[] urls =
{
"https://demo.leadtools.com/images/pdf/leadtools.pdf",
"https://demo.leadtools.com/images/tiff/ocr.tif",
"https://demo.leadtools.com/images/png/pngimage.png"
};
// Setup a callback for logging
// DocumentMimeTypes & DocumentMimeTypes.UserGetDocumentStatusHandler reference
DocumentMimeTypes.UserGetDocumentStatusHandler userGetDocumentStatus = (Uri uri, LoadDocumentOptions options, DocumentMimeTypeSource source, string mimeType) =>
{
// Use default operation
DocumentMimeTypeStatus status = DocumentFactory.MimeTypes.GetDocumentStatus(uri, options, source, mimeType);
string mimeTypeValue = mimeType != null ? mimeType : "[null]";
DocumentFactory.MimeTypes.GetStatus(mimeTypeValue);
Console.WriteLine(string.Format(" ** Whitelist url:{0} source:{1} mimeType:{2} status:{3}", uri.ToString(), source, mimeTypeValue, status));
return status;
};
DocumentFactory.MimeTypes.UserGetDocumentStatus = userGetDocumentStatus;
// Load the documents, by default we should load all of them
Console.WriteLine("Everything should load OK");
LoadDocuments(urls);
// Now, disable loading everything except PDF and TIFF and try again
Console.WriteLine("Disabling everything except PDF and TIFF");
DocumentFactory.MimeTypes.DefaultStatus = DocumentMimeTypeStatus.Denied;
DocumentFactory.MimeTypes.Entries.Add("application/pdf", DocumentMimeTypeStatus.Allowed);
DocumentFactory.MimeTypes.Entries.Add("image/tiff", DocumentMimeTypeStatus.Allowed);
Console.WriteLine("Only PDF and TIFF should be loaeded");
LoadDocuments(urls);
// Reset
DocumentFactory.MimeTypes.UserGetDocumentStatus = null;
}
private static void LoadDocuments(string[] urls)
{
var loadDocumentOptions = new LoadDocumentOptions();
foreach (var url in urls)
{
Console.WriteLine(" Loading " + url);
using (var document = DocumentFactory.LoadFromUri(new Uri(url), loadDocumentOptions))
{
if (document != null)
Console.WriteLine(" is Loaded");
else
Console.WriteLine(" cannot be loaded");
}
}
}