自定义 XSLT 转换实现

ITransform2 类

从 BizTalk Server 2020 开始，BizTalk 映射支持自定义 XSLT 转换引擎。 可以通过在程序集Microsoft.XLANGs.BaseTypes.dll中定义派生自抽象类 Microsoft.XLANGs.BaseTypes.ITransform2 的 XSLT 转换实现来实现自定义 XSLT 转换引擎。

    public abstract class ITransform2
    {
       // This is not required, user can implement if they want their transform support custom extension.
       // These 3 parameters passed in are from "Custom Extension XML", in which user can provide namespace, assembly name, class name of the extension object, here user should create the extension behavior, like extension object creation, and registry.
        public virtual void RegisterExtension(string namespaceUri, string assemblyName, string className);
               
        // Load XSLT string.
        public abstract void Load(string xslt);

        // Transform input stream into out string.
        // Notice BizTalk actually doesn't support xslt arguments for now, it is reserved for future usage.
        public abstract void Transform(Stream input, IDictionary<XmlQualifiedName, object> xsltArguments, Stream results);
    }

实现示例

using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Reflection;
using System.Xml;
using Microsoft.BizTalk.ScalableTransformation;
using Microsoft.XLANGs.BaseTypes;
using Saxon.Api;

namespace CustomTransform
{
    public class SaxonEEXsltTransform : ITransform2
    {
        protected bool legacyWhitespaceBehavior;
        protected Processor processor;
        protected XsltCompiler compiler;
        protected Xslt30Transformer transformer;

        public SaxonEEXsltTransform()
        {
            this.legacyWhitespaceBehavior = Microsoft.BizTalk.ScalableTransformation.BTSXslTransform.LegacyWhitespaceBehavior;

			// You have to put your license file in the designated place if you set "licensedEdition" as true. 
            this.processor = new Processor(true);

            this.processor.SetProperty(FeatureKeys.STRIP_WHITESPACE, this.legacyWhitespaceBehavior ? "all" : "none");
            this.compiler = processor.NewXsltCompiler();
        }

        public override void RegisterExtension(string namespaceUri, string assemblyName, string className)
        {
            Assembly assembly = Assembly.Load(assemblyName);
            Object obj = assembly.CreateInstance(className);

            ExtensionFunction function = obj as ExtensionFunction;
            if (function != null)
            {
                this.processor.RegisterExtensionFunction(function);
            }

            ExtensionFunctionDefinition functionDefinition = obj as ExtensionFunctionDefinition;
            if (functionDefinition != null)
            {
                this.processor.RegisterExtensionFunction(functionDefinition);
            }

            if (function == null && functionDefinition == null)
            {
                throw new ArgumentException(string.Format("Invalid extension class {0}, it should be of type {1} or {2}.", className, typeof(ExtensionFunction).Name, typeof(ExtensionFunctionDefinition).Name));
            }
        }

        public override void Load(string xslt)
        {
            XsltExecutable executable = this.compiler.Compile(new StringReader(xslt));
            this.transformer = executable.Load30();
        }

        public override void Transform(Stream input, IDictionary<XmlQualifiedName, object> xsltArguments, Stream results)
        {
            if (xsltArguments != null)
            {
                Dictionary<QName, XdmValue> parameters = new Dictionary<QName, XdmValue>();
                foreach (XmlQualifiedName name in xsltArguments.Keys)
                {
                    parameters[new QName(name)] = new XdmExternalObjectValue(xsltArguments[name]);
                }

                this.transformer.SetStylesheetParameters(parameters);
            }

            this.transformer.InputXmlResolver = new XmlUrlResolver();
            Serializer serializer = processor.NewSerializer();
            serializer.SetOutputStream(results);
            this.transformer.ApplyTemplates(input, serializer);
            serializer.Close();
        }
    }
}

另请参阅

XSLT 自定义转换引擎属性

自定义扩展 XML