Develop Reference

How to Debug System.Text.Json Deserializer

In the case of deserializing JSON data using System.Text.Json where the data doesn't match the target model, it throws a NotSupportedException with no detail whatsoever.
If the data is complex, it can be very difficult to pin-point where the problem occurred.
Is there a way to get some more debug information, or some hint as to which member failed to deserialize?
EDIT
Here's a sample command
var result = await JsonSerializer.DeserializeAsync<ApiResponse<T>>(responseStream, OntraportSerializerOptions.Default, CancellationToken.None).ConfigureAwait(false);
Error message:
The collection type 'System.Collections.Generic.Dictionary2[System.Int32,OntraportApi.Models.ResponseSectionFields]' on 'OntraportApi.Models.ApiResponse1[System.Collections.Generic.Dictionary`2[System.Int32,OntraportApi.Models.ResponseSectionFields]].Data' is not supported.'
responseStream.Length = 18494, want me to paste it?

Identify Cause of Serialization Error Coming From Inside Library/NuGet Package

Sometimes when calling the Mastercard MATCH API via the NuGet package MasterCard-Match, I will get a JSON deserialization exception:
Unexpected character encountered while parsing value: <. Path '',
line 0, position 0.
The exception is from MasterCard.Core with an inner exception from Newtonsoft.Json, both have the same message.
It looks like I'm receiving HTML ('<' at line 0, position 0) and the library is trying to deserialize it as JSON. My guess is that the MasterCard API is sending back an HTML error page instead of a JSON error. But I can't step into the function call to "see" the response its getting before throwing the exception.
As per the documentation I create a request map with the provided data and call TerminationInquiryRequest.Create(map), this is the line the exception is thrown. This function call is a black box, I can't step into it, it just throws the exception.
try
{
RequestMap requestMap = CreateRequestMap();
// This line throws the exception
TerminationInquiryRequest apiResponse = TerminationInquiryRequest.Create(requestMap);
}
catch(Exception e)
{
// Exception handling
}
I've made over 11,000+ calls using this library and only 32 have had this error, but of course I get to hear about it every time it happens.
Is there any way to debug libraries that I'm not aware of, or a way to view the response that the library is getting from the API?
I already have some logic to wait and retry the call if it fails.

Transforming XML with XSL to HTML Saxon library in .NET

I am programming in C#. I was previously using the following command line to convert an xml with a xsl and output it as a html.
java -jar "C:\Data\saxon-he-9.4.0.7.jar" View.xml Stylesheet.xsl -o:output.html
However, I am now trying to use the Saxon .Net API to do the same process using the following code:
var xslt = new FileInfo(#"C:\\Data\\Stylesheet.xsl");
var input = new FileInfo(#"C:\\Data\\View.xml");
var output = new FileInfo(#"C:\\Data\\test.html");
// Compile stylesheet
var processor = new Processor();
var compiler = processor.NewXsltCompiler();
var executable = compiler.Compile(new Uri(xslt.FullName));
// Do transformation to a destination
var destination = new DomDestination();
using (var inputStream = input.OpenRead())
{
var transformer = executable.Load();
transformer.SetInputStream(inputStream, new Uri(input.DirectoryName));
transformer.Run(destination);
}
// Save result to a file (or whatever else you wanna do)
destination.XmlDocument.Save(output.FullName);
However I recieve the error:
"An unhandled exception of type 'Saxon.Api.DynamicError' occurred in saxon9he-api.dll"
When running the line "transformer.Run(destination);"
The following screenshots are from the Visual Studio's Locals Debugging:
$exception {"XSLT 1.0 compatibility mode is not available in this configuration"} Saxon.Api.DynamicError
transformer {Saxon.Api.XsltTransformer} Saxon.Api.XsltTransformer

The first thing you need to do is to get more specific information about the nature of the error. Catching the exception and printing the exception message would be a good start. But Saxon will have written diagnostics to the standard error output, which probably ends up in some log file somewhere, depending on how your application is configured and run. If you can't track it down, try redirecting it as described here: How to capture a Processes STDOUT and STDERR line by line as they occur, during process operation. (C#)
Once you've established the actual error, edit the question and we can start investigating what's wrong if it's not obvious.
A common cause of problems when writing to a DomDestination is that your result tree isn't well-formed, e.g, it has text nodes or multiple elements at the top level. It's not clear why you are writing to a DomDestination - if you just want to produce serialized XML, then write to a Serializer.
LATER
Now you've found the error message ("XSLT 1.0 compatibility mode is not available in this configuration") it should be fairly clear. When a stylesheet specifies version="1.0" and is run with an XSLT 2.0 or 3.0 processor, it runs in a compatibility mode where certain things behave differently (for example xsl:value-of ignores all but the first selected item). This compatibility mode, from Saxon 9.8 onwards, is not available in Saxon-HE. You need to do one of three things: upgrade to Saxon-PE or -EE; revert to an earlier Saxon-HE version; or convert your stylesheet to XSLT 2.0 (which basically means (i) change the value of the version attribute (ii) test that it still works.)

Search with SharePoint CSOM (portable) throws an exception

I am trying to use SharePoint client framework to execute a search, using the portable dll's from a Windows app.
Using Fiddler I can see that my search is executed, and returns a JSON collection of metadata and search results. This is identical to the result from the non-portable CSOM.
When CSOM tries to map the result to it's data objects I get the following exception:
Unable to cast object of type 'System.Collections.Generic.Dictionary`2[System.String,System.Object]' to type 'Microsoft.SharePoint.Client.Search.Query.ResultTableCollection'.
This exception occurs inside CSOM (portable). Non-portable CSOM runs without exception, and returns the expected result.
The code I am running to get this exception is:
var query = new KeywordQuery(ctx);
query.QueryText = "something";
var executor = new SearchExecutor(ctx);
var results = executor.ExecuteQuery(query);
await ctx.ExecuteQueryAsync();
In the above, ctx is a ClientContext that has already been authenticated. Other requests, such as getting a specific list, works as expected.
I am referencing the following dll's from c:\Program Files\Common Files\microsoft shared\Web Server Extensions\16\ISAPI:
Microsoft.SharePoint.Client.Portable.dll
Microsoft.SharePoint.Client.Runtime.Portable.dll
Microsoft.SharePoint.Client.Runtime.WindowsStore.dll
Microsoft.SharePoint.Client.Search.Portable.dll
My question is.
How do I solve this, so that I can use CSOM to run search queries from a Windows Store app?
UPDATE:
I added the following after authenticating the ClientContext:
ctx.ExecutingWebRequest += (s, e) =>
e.WebRequest.Headers["Accept-Encoding"] = "gzip, deflate";
This solved the immediate problem, but introduced a new one. I am now getting a System.FormatException:
Not well formatted JSON stream.
Since the JSON from portable and non-portable CSOM is the same, there should not be a parsing error in one CSOM and not the other.

What I can identify from your exception is that casting of execute query result creates problem here.
Use below code to cast execute query result
ResultTable rtSharePointSearchResult = new ResultTable();
KeywordQuery query = new KeywordQuery(clientContext);
query.QueryText = "Keywords";
query.TrimDuplicates = false;
SearchExecutor searchExecutor = new SearchExecutor(clientContext);
ClientResult<ResultTableCollection> results = searchExecutor.ExecuteQuery(query);
clientContext.ExecuteQuery();
rtSharePointSearchResult = results.Value[0];

Notice that the first post uses ctx.ExecuteQueryAsync but the "answer" uses ctx.ExecuteQuery.
The bug is in the portable class library (that the first post uses) but this works in the non-portable version (the second post).
Cheers,
Paul

Unsupported Media Type error when using json-patch in Ramone

Update: I downloaded Ramone project, added it to my project and then ran the application again with debugger. The error is shown below:
public MediaTypeWriterRegistration GetWriter(Type t, MediaType mediaType)
{
...
CodecEntry entry = SelectWriters(t, mediaType).FirstOrDefault(); => this line throws error
...
}
Error occurs in CodecManager.cs. I am trying to figure out why it does not recognize json-patch media type. Could it be because writer is not being registered correctly? I am looking into it. If you figure out the problem, please let me know. Since you are the author of the library, it will be easier for you to figure out the issue. I will have to go through all the code files and methods to find the issue. Thanks!
I was excited to know that Ramone library supports json-patch operations but when I tried it, I got following error:
415- Unsupported Media Type
This is the same error that I get when I use RestSharp. I thought may be RestSharp does not support json-patch and errors out so I decided to try Ramone lib but I still get same error. Endpoint has no issues because when I try same command using Postman, it works but when I try it programmatically in C#, it throws unsupported media type error. Here is my code:
var authenticator = new TokenProvider("gfdsfdsfdsafdsafsadfsdrj5o97jgvegh", "sadfdsafdsafdsfgfdhgfhehrerhgJ");
JsonPatchDocument patch = new JsonPatchDocument<MetaData>();
patch.Add("/Resident2", "Boyle");
//patch.Replace("/Resident", "Boyle");
RSession = RamoneConfiguration.NewSession(new Uri("https://api.box.com"));
RSession.DefaultRequestMediaType = MediaType.ApplicationJson;
RSession.DefaultResponseMediaType = MediaType.ApplicationJson;
Ramone.Request ramonerequest = RSession.Bind("/2.0/files/323433290812/metadata");
ramonerequest.Header("Authorization", "Bearer " + authenticator.GetAccessToken(code).AccessToken);
//var ramoneresponse = ramonerequest.Patch(patch); //results in error: 405 - Method Not Allowed
var ramoneresponse = ramonerequest.Put(patch); //results in error: 415 - Unsupported Media Type
var responsebody = ramoneresponse.Body
Endpoint information is available here: http://developers.box.com/metadata-api
I used json-patch section in the following article as a reference:
http://elfisk.dk/Ramone/Documentation/Ramone.pdf
By the way I tried Patch() method (as shown in above ref. article) but that resulted in "Method not allowed" so I used Put() method which seems to work but then errors out because of json-patch operation.
Any help, guidance, tips in resolving this problem will be highly appreciated. Thanks much in advance.
-Sham

The Box documentation says you should use PUT (which is quite a bit funny). The server even tells you that it doesn't support the HTTP PATCH method (405 Method Not Allowed) - so PUT it must be.
Now, you tell Ramone to use JSON all the time (RSession.DefaultRequestMediaType = MediaType.ApplicationJson), so you end up PUT'ing a JSON document to Box - where you should be PUT'ing a JSON-Patch document.
Drop the "RSession.DefaultRequestMediaType = MediaType.ApplicationJson" statement and send the patch document as JSON-Patch with the use of: ramonerequest.ContentType("application/json-patch+json").Put(...).