Saxon 中的 BaseUri 在尝试编译 xslt 内容时导致问题

Question

这是我的代码：

static void Main(string[] args)
{
    string xml = File.ReadAllText("C:/Users/Davíð/source/Saxon/Saxon/data.xml");
    string xslt = File.ReadAllText("C:/Users/Davíð/source/Saxon/Saxon/dataXslt.xsl");
    string xmlCopy = File.ReadAllText("C:/Users/Davíð/source/Saxon/Saxon/data.xml");

    TransformData(xml, xmlCopy, xslt);
}

static public void TransformData(string data, string xmlCopy, string xslt)
{
    // Create a Processor instance.
    Processor processor = new Processor();

    // Create a compiled stylesheet
    processor.NewXsltCompiler().BaseUri = new Uri("C:/Users/Davíð/source/Saxon/Saxon");
    XsltExecutable templates = processor.NewXsltCompiler().Compile(new XmlTextReader(new StringReader(xslt)));

    // Note: we could actually use the same Xslt30Transformer in this case.
    // But in principle, the two transformations could be done in parallel in separate threads.

    // Do the first transformation
    Console.WriteLine("\n\n----- transform of " + data + " -----");
    Xslt30Transformer transformer1 = templates.Load30();
    XdmNode input1 = processor.NewDocumentBuilder().Build(new XmlTextReader(new StringReader(data)));
    transformer1.ApplyTemplates(input1, processor.NewSerializer(Console.Out));     // default destination is Console.Out

    // Do the second transformation
    Console.WriteLine("\n\n----- transform of " + xmlCopy + " -----");
    Xslt30Transformer transformer2 = templates.Load30();
    XdmNode input2 = processor.NewDocumentBuilder().Build(new XmlTextReader(new StringReader(xmlCopy)));
    transformer2.ApplyTemplates(input2, processor.NewSerializer(Console.Out));     // default destination is Console.Out
}

这是无论我是否删除 BaseUri 都会出现的错误。

未处理的异常：System.ArgumentNullException：值不能为空。参数名称：BaseUri 在 Saxon.Api.XsltCompiler.Compile(XmlReader reader) 在 Saxon.Program.TransformData(String data, String xmlCopy, String xslt) in C:\Users\Davíð\source\Saxon\Saxon\Program.cs:line 33 在 Saxon.Program.Main(String[] args) 在 C:\Users\Davíð\source\Saxon\Saxon\Program.cs:line 22

根据评论，修复了下面的工作代码：

static void Main(string[] args)

{
    string xml = File.ReadAllText("C:/Users/Davíð/source/Saxon/Saxon/data.xml");
    string xslt = File.ReadAllText("C:/Users/Davíð/source/Saxon/Saxon/dataXslt.xsl");

    TransformData(xml, xml, xslt);
}

static public void TransformData(string data, string xmlCopy, string xslt)
{
    // Create a Processor instance.
    Processor processor = new Processor();

    // Create a compiled stylesheet
    var compiler = processor.NewXsltCompiler();
    compiler.BaseUri = new Uri("C:/Users/Davíð/source/Saxon/Saxon");
    XsltExecutable templates = compiler.Compile(XmlReader.Create(new StringReader(xslt)));

    // Note: we could actually use the same Xslt30Transformer in this case.
    // But in principle, the two transformations could be done in parallel in separate threads.

    // Do the first transformation
    Console.WriteLine("\n\n----- transform of " + data + " -----");
    Xslt30Transformer transformer1 = templates.Load30();
    XdmNode input1 = processor.NewDocumentBuilder().Build(XmlReader.Create(new StringReader(data)));
    transformer1.ApplyTemplates(input1, processor.NewSerializer(Console.Out));     // default destination is Console.Out

    // Do the second transformation
    Console.WriteLine("\n\n----- transform of " + xmlCopy + " -----");
    Xslt30Transformer transformer2 = templates.Load30();
    XdmNode input2 = processor.NewDocumentBuilder().Build(new XmlTextReader(new StringReader(xmlCopy)));
    transformer2.ApplyTemplates(input2, processor.NewSerializer(Console.Out));     // default destination is Console.Out
}

Answer 1

您有几个问题：

processor.NewXsltCompiler() returns 每次调用一个新的 XsltCompiler 。你叫它两次：
```
processor.NewXsltCompiler().BaseUri = new Uri("C:/Users/Davíð/source/Saxon/Saxon");
XsltExecutable templates = processor.NewXsltCompiler().Compile(new XmlTextReader(new StringReader(xslt)));
```
代码首先设置BaseUri，然后创建另一个进行编译。因此 BaseUri 永远不会设置在实际用于工作的 XsltCompiler 上。

这是异常的直接原因未处理的异常：System.ArgumentNullException：值不能为空。参数名称：Saxon.Api.XsltCompiler.Compile(XmlReader reader) 处的 BaseUri。

您应该只创建一个 XsltCompiler。
您正在使用 XmlTextReader，但 XmlTextReader has been deprecated since .Net 2.0 over 10 years ago. Instead, use XmlReader.Create(TextReader)。另外，请务必事后处理。
您将文件 data.xml 内容的两个副本加载到内存中，加载到字符串 xml 和 xmlCopy 中。但是 .Net 中的字符串是不可变的，所以没有必要这样做。

因此您的代码应该类似于：

public static void Main(string[] args)
{
    string xml = File.ReadAllText("C:/Users/Davíð/source/Saxon/Saxon/data.xml");
    string xslt = File.ReadAllText("C:/Users/Davíð/source/Saxon/Saxon/dataXslt.xsl");

    TransformData(xml, xml, xslt);
}

static public void TransformData(string xml1, string xml2, string xslt)
{
    // Create a Processor instance.
    var processor = new Processor();

    // Create a compiled stylesheet
    var compiler = processor.NewXsltCompiler();
    compiler.BaseUri = new Uri("C:/Users/Davíð/source/Saxon/Saxon");
    XsltExecutable templates;
    using (var reader = XmlReader.Create(new StringReader(xslt)))
        templates = compiler.Compile(reader);

    // Note: we could actually use the same Xslt30Transformer in this case.
    // But in principle, the two transformations could be done in parallel in separate threads.

    // Do the first transformation
    Console.WriteLine("\n\n----- transform of " + xml1 + " -----");
    TransformData(processor, templates, xml1, Console.Out);

    // Do the second transformation
    Console.WriteLine("\n\n----- transform of " + xml2 + " -----");
    TransformData(processor, templates, xml2, Console.Out);
}

private static void TransformData(Processor processor, XsltExecutable templates, string xml, TextWriter output)
{
    var transformer = templates.Load30();
    using (var reader = XmlReader.Create(new StringReader(xml)))
    {
        var input = processor.NewDocumentBuilder().Build(reader);
        transformer.ApplyTemplates(input, processor.NewSerializer(output));
    }
}

Saxon 中的 BaseUri 在尝试编译 xslt 内容时导致问题

BaseUri in Saxon causing problems when trying to compile xslt content

c#

xml

xslt

uri

saxon