I cannot understand when validation of XML occurs on Load or on Validate. Here is following code...
XmlDocument doc = null;
try
{
XmlReaderSettings settings = new XmlReaderSettings( );
settings.Schemas.Add("http://xxx/customs/DealFile/Common/ReleaseGoodsMessage",
ConfigurationManager.AppSettings.Get("Schemas"));
settings.ValidationType = ValidationType.Schema;
using (XmlReader reader = XmlReader.Create(path, settings)) {
doc = new XmlDocument( );
doc.Load(reader);
}
ValidationEventHandler eventHandler = new ValidationEventHandler(ValidationEventHandler);
doc.Validate(eventHandler);
}
catch(XmlSchemaException xmlErr)
{
// Do something
}
I expect a validation to occur on line doc.Validate(eventHandler);
However it always occurs on doc.Load(reader); . I've got an exception if something wrong with XML.
XMLHelpers.LoadXML(#"C:\work\Xml2Db\Xml2Db\Data\Tests\BadData\01.xml")
Exception thrown: 'System.Xml.Schema.XmlSchemaValidationException' in System.Xml.dll
xmlErr.Message
"The 'http://xxx/customs/DealFile/Common/ReleaseGoodsMessage:governmentProcedureType' element is invalid -
The value 'a' is invalid according to its datatype 'Int' - The string 'a' is not a valid Int32 value."
And this is the code from Microsoft's example https://learn.microsoft.com/en-us/dotnet/api/system.xml.xmldocument.validate?view=netcore-3.1
try
{
XmlReaderSettings settings = new XmlReaderSettings();
settings.Schemas.Add("http://www.contoso.com/books", "contosoBooks.xsd");
settings.ValidationType = ValidationType.Schema;
XmlReader reader = XmlReader.Create("contosoBooks.xml", settings);
XmlDocument document = new XmlDocument();
document.Load(reader);
ValidationEventHandler eventHandler = new ValidationEventHandler(ValidationEventHandler);
// the following call to Validate succeeds.
document.Validate(eventHandler);
...
It's actually the same.
But, pay attention on comment // the following call to Validate succeeds. . They also expect to get validation on the line document.Validate(eventHandler);
What's going on.
As your block of code sets up the settings object, it sets a schema and the Validator to use ValidationType.Schema (i.e.: use the schema).
When you setup the XmlReader, using your settings it's setup to validate according to the schema, too - which is causing your schema-based error/exception.
The call to document.Validate(eventHandler); is completely redundant, because it will succeed in all circumstances - because the xml has already been validated. The comment is correct "the following call to Validate succeeds" because the document has already been proved valid.
I suspect that you are failing to distinguish between XML that is well-formed and XML that is valid.
A well-formed XML document satisfies all of the rules of the XML specification. If it does not, you should get a well-formedness error from any XML parser.
If you also choose to
a) supply an XSD that describes you XML document and
b) tell your XML processor to validate against that XSD
then the XML processor will also check that the document satisfies the rules in the XML schema (an XML Schema is composed of one or more XSDs).
If you are still not sure, edit your question and supply the error message(s) that you are seeing. You don't need to include any confidential information - the error template is enough to tell which kind of error it is.
Related
I'm trying to validate my XML using external dtd file. Here is XML header:
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE CONTEXT SYSTEM "Data.dtd">
<CONTEXT>
...
</CONTEXT>
And here is my code:
// Set the validation settings.
XmlReaderSettings settings = new XmlReaderSettings();
settings.DtdProcessing = DtdProcessing.Parse;
settings.ValidationType = ValidationType.DTD;
settings.ValidationEventHandler += (sender, args) => Debug.WriteLine(args.Message);
// Create the XmlReader object.
XmlReader reader = XmlReader.Create("Data.xml", settings);
// Parse the file.
while (reader.Read());
After running this code I receive in result a lot of errors looks the same way:
The 'CONTEXT' element is not declared.
I've tried to change file name in doctype for obviously nonexistent file, but as result get the same errors. Please tell me where have I been mistaken?
I could reproduce the problem, as a fix I would suggest to set
settings.XmlResolver = new XmlUrlResolver();
that way, the external DTD file is fetched, it seems, otherwise not. The documentation on MSDN says: "Starting with the .NET Framework 4.5.2, this setting has a default value of null.". So it seems, you need to create it explicitly.
I got an error that i can't solve for the moment
The code :
var myXslTrans = new XslCompiledTransform();
myXslTrans.Load(stylesheet);
myXslTrans.Transform(sourceFile , outputFile);
The error :
For safety reasons, DTC prohibited in this XML document To enable DTD
processing , set on the Parse DtdProcessing property XmlReaderSettings
and pass parameters to the XmlReader.Create method
I have tried with the XmlReaderSettings (DtdProcessing, DtdProcessing.Parse) but i didn't find the answer
If the stylesheet document uses a DTD (e.g. has <!DOCTYPE xsl:stylesheet ...>) then load it with
using (XmlReader xr = XmlReader.Create(stylesheet, new XmlReaderSettings() { DtdProcessing = DtdProcessing.Parse }))
{
myXslTrans.Load(xr);
}
If the sourceFile uses a DTD then load it with such an XmlReader passed as the first argument to the Transform method, you might then need a different overload of that method for the second and third argument.
tryin to parse an xml file gives me the following error
Reference to undeclared entity 'eacute'
after I created a dtd file with all the entities that I found here http://www.w3.org/TR/xhtml1/dtds.html and I loaded it as follows
XmlReaderSettings settings = new XmlReaderSettings();
settings.ProhibitDtd = false;
string s = System.IO.File.ReadAllText(#"..\xhtml-lat1.ent");
XmlParserContext con = new XmlParserContext(null, null, "iti", null, null, s, "", "", XmlSpace.None);
XmlReader reader = XmlReader.Create(stream, settings, con);
the loading an xdocument
XDocument doc = XDocument.Load(reader);
give me the following exception '=' is an unexpected token. The expected token is ';'.
any suggestions please
Generally, this error happens when the xml document is not well-formed.
One tip to find the error, open your xml document in Internet Explorer. If the xml document is not well-formed, Internet Explorer will not be able to load the entire document and will tell you where the error is located.
If I recall correctly, the only place a semicolon matters in XML is in an entity encoding. I would check for an incomplete entity (maybe é) or a special character in the document that should be encoded.
I wanna verify a digitally signed xml against its schema definition while this schema actually contains this tag
<xs:import namespace="http://www.w3.org/2000/09/xmldsig#" schemaLocation="xmldsig-core-schema.xsd" id="schema"/>
Then I tried to load schemas:
XmlReaderSettings settings = new XmlReaderSettings();
settings.Schemas.Add(null, "a.xsd");
settings.Schemas.Compile();
I will get the following error
The 'http://www.w3.org/2000/09/xmldsig#:Signature' element is not declared.
You need to also load in the imported schema with another
settings.Schemas.Add([importednamespace], [pathtoimportedXSD]);
The scheme xmldsig-core-schema.xsd does not charge for security reasons since it makes reference to a DTD to validate the upload directory and add it as another scheme.
<!DOCTYPE schema PUBLIC "-//W3C//DTD XMLSchema 200102//EN" "http://www.w3.org/2001/XMLSchema.dtd"
this works
The solution is C#
XElement xsdMarkup = XElement.Load("C:\\Proyectos\\WindowService\\Sbif\\Schema\\Schema\\IndicadoresFinancieros-v1.0.xsd");
XElement xsdMarkup2 = XElement.Load("http://www.w3.org/TR/2002/REC-xmldsig-core-20020212/xmldsig-core-schema.xsd");
XmlSchemaSet schemas = new XmlSchemaSet();
schemas.Add(null, xsdMarkup.CreateReader());
schemas.Add(null, xsdMarkup2.CreateReader());
schemas.Compile();
are you sure hash is required at the end of?:
http://www.w3.org/2000/09/xmldsig#
From the error it would seem the XML Signature schema is not being loaded, despite the import.
Adding the XML Signature schema to the schema set explicitly should confirm that.
The most likely cause is the schema set's XmlReslver is not finding the file you specify, this could be a current folder/relative path issue.
Using Process Monitor to see where you could is trying to load the XSD file may also help.
When using XmlDocument.Load , I am finding that if the document refers to a DTD, a connection is made to the provided URI. Is there any way to prevent this from happening?
After some more digging, maybe you should set the XmlResolver property of the XmlReaderSettings object to null.
'The XmlResolver is used to locate and
open an XML instance document, or to
locate and open any external resources
referenced by the XML instance
document. This can include entities,
DTD, or schemas.'
So the code would look like this:
XmlReaderSettings settings = new XmlReaderSettings();
settings.XmlResolver = null;
settings.DtdProcessing = DtdProcessing.Parse;
XmlDocument doc = new XmlDocument();
using (StringReader sr = new StringReader(xml))
using (XmlReader reader = XmlReader.Create(sr, settings))
{
doc.Load(reader);
}
The document being loaded HAS a DTD.
With:
settings.ProhibitDtd = true;
I see the following exception:
Service cannot be started. System.Xml.XmlException: For security reasons DTD is prohibited in this XML document. To enable DTD processing set the ProhibitDtd property on XmlReaderSettings to false and pass the settings into XmlReader.Create method.
So, it looks like ProhibitDtd MUST be set to true in this instance.
It looked like ValidationType would do the trick, but with:
settings.ValidationType = ValidationType.None;
I'm still seeing a connection to the DTD uri.
This is actually a flaw in the XML specifications. The W3C is bemoaning that people all hit their servers like mad to load schemas billions of times. Unfortunately just about no standard XML library gets this right, they all hit the servers over and over again.
The problem with DTDs is particularly serious, because DTDs may include general entity declarations (for things like & -> &) which the XML file may actually rely upon. So if your parser chooses to forgo loading the DTD, and the XML makes use of general entity references, parsing may actually fail.
The only solution to this problem would be a transparent caching entity resolver, which would put the downloaded files into some archive in the library search path, so that this archive would be dynamically created and almost automatically bundled with any software distributions made. But even in the Java world there is not one decent such EntityResolver floating about, certainly not built-in to anything from apache foundation.
Try something like this:
XmlDocument doc = new XmlDocument();
using (StringReader sr = new StringReader(xml))
using (XmlReader reader = XmlReader.Create(sr, new XmlReaderSettings()))
{
doc.Load(reader);
}
The thing to note here is that XmlReaderSettings has the ProhibitDtd property set to true by default.
Use an XMLReader to load the document and set the ValidationType property of the reader settings to None.