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+--- Thread: Having difficulty exposing XmlDocument to JScript using ClearScript (/Thread-Having-difficulty-exposing-XmlDocument-to-JScript-using-ClearScript)
Having difficulty exposing XmlDocument to JScript using ClearScript - versabilityqryalx - 07-24-2023
Context: Windows Azure; Visual Studio Community 2015; ClearScript; JScript
I'm having problems exposing an XmlDocument object to the JScripts I'm executing using ClearScript.
I am instantiating a JScript interpreter using
JScriptEngine JSengine = new JScriptEngine(WindowsScriptEngineFlags.EnableDebugging | WindowsScriptEngineFlags.EnableJITDebugging);
To instantiate the XmlDocument object I have tried both
using System.Xml;
...
JSengine.AddHostType("CSXmlDocument", typeof(XmlDocument));
...
and
...
JSengine.AddCOMObject("CSXmlDocument", "MSXML2.DOMDocument");
...
and I execute the JScript script using this
...
object answer = JSengine.Evaluate(File.ReadAllText(rulesetFilename));
...
My difficulty is in how to use the `CSXmlDocument` object inside the script. I have tried all of the following to no avail.
var xmlObj1 = CSXmlDocument;
var xmlObj2 = new CSXmlDocument;
var xmlObj3 = CSXmlDocument();
var xmlObj4 = new CSXmlDocument();
When `CSXmlDocument` is defined using `AddCOMObject`, the second through fourth invocations give an error of
Unable to evaluate the expression. Operation not supported. Unknown error: 0x8013baff.
The first invocation only gives me access to three methods, `Equals`, `GetHashCode`, `GetType`.
When `CSXmlDocument` is defined using `AddHostType`, the first gives just the three methods as above. The second invocation seems to give access to the full set of properties and methods (at least that's what VS2015 says in a debugging session) however, when I try to use the `LoadXml` method I get
xmlObj2.LoadXml(body)
Unable to evaluate the expression. Operation not supported. Unknown error: 0x8013baff.
I am currently working through two possible gotchas:
1. Character encoding, in the light of [another StackOverflow posting][1].
2. HTML-XML markup conflicts.
[1]:
[To see links please register here]
RE: Having difficulty exposing XmlDocument to JScript using ClearScript - candlenut186803 - 07-24-2023
Hmm, I'm not sure what you're doing differently, but the following works for me:
using (var JSengine = new JScriptEngine())
{
JSengine.AddHostType("CSXmlDocument", typeof(XmlDocument));
JSengine.AddHostType("CSConsole", typeof(Console));
JSengine.Execute(@"
var doc = new CSXmlDocument();
doc.LoadXml('<Hello>World</Hello>');
var node = doc.FirstChild;
CSConsole.WriteLine('{0} {1}!', node.Name, node.InnerText);");
}
This produces the expected output "Hello World!" with ClearScript 5.4.4. Does it work for you?
RE: Having difficulty exposing XmlDocument to JScript using ClearScript - parcheesi696870 - 07-24-2023
Instead of passing in the object, I elected to create the object in the script. Thus I have
var htmlDoc = new ActiveXObject("Msxml2.FreeThreadedDOMDocument.6.0");
What benefit there is in using `FreeThreaded` I don't know but it's working.
I still had problems, mind you, with how Msxml2 was handling the HTML I was throwing at it, and had to add the following
htmlDoc.setProperty("ProhibitDTD", false);
htmlDoc.validateOnParse = false;
Also Msxml2 can't handle `&nbsp;` so I swapped that for its character equivalent:
body = body.replace(/&nbsp;/g, "&#160;");
The `ProhibitDTD` meant that ripping out the DOCTYPE was also required, viz
body = body.replace("<!DOCTYPE html>", "");
With all that done, the rest happened fairly quickly:
htmlDoc.loadXML(body);
leadLink = htmlDoc.selectNodes('//*[@title="View this lead"]')[0].attributes[0].value;