如何使用XSLT转换XML?

时间:2019-01-03 17:55:40

标签: xml delphi xslt delphi-2007

我有一个XML文件和一个XSLT,我想使用XSLT将XML转换为HTML字符串,然后可以将其加载到TWebBrowser中。

对于我的测试,我使用的是these示例文件。

XML文件:

<?xml version="1.0" encoding="UTF-8"?>
<breakfast_menu>

<food>
<name>Belgian Waffles</name>
<price>$5.95</price>
<description>Two of our famous Belgian Waffles with plenty of real maple syrup</description>
<calories>650</calories>
</food>

<food>
<name>Strawberry Belgian Waffles</name>
<price>$7.95</price>
<description>Light Belgian waffles covered with strawberries and whipped cream</description>
<calories>900</calories>
</food>

<food>
<name>Berry-Berry Belgian Waffles</name>
<price>$8.95</price>
<description>Light Belgian waffles covered with an assortment of fresh berries and whipped cream</description>
<calories>900</calories>
</food>

<food>
<name>French Toast</name>
<price>$4.50</price>
<description>Thick slices made from our homemade sourdough bread</description>
<calories>600</calories>
</food>

<food>
<name>Homestyle Breakfast</name>
<price>$6.95</price>
<description>Two eggs, bacon or sausage, toast, and our ever-popular hash browns</description>
<calories>950</calories>
</food>

</breakfast_menu>

XSLT文件:

<?xml version="1.0" encoding="UTF-8"?>
<html xsl:version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<body style="font-family:Arial;font-size:12pt;background-color:#EEEEEE">
<xsl:for-each select="breakfast_menu/food">
  <div style="background-color:teal;color:white;padding:4px">
    <span style="font-weight:bold"><xsl:value-of select="name"/> - </span>
    <xsl:value-of select="price"/>
    </div>
  <div style="margin-left:20px;margin-bottom:1em;font-size:10pt">
    <p>
    <xsl:value-of select="description"/>
    <span style="font-style:italic"> (<xsl:value-of select="calories"/> calories per serving)</span>
    </p>
  </div>
</xsl:for-each>
</body>
</html>

尝试1:

我找到了this解决方案并尝试了该功能:

Uses
  XMLDoc, XMLIntf;

function Transform(XMLContent : string; XSLContent : string) : WideString;
var
  XML : IXMLDocument;
  XSL : IXMLDocument;
begin

  XML := LoadXMLData(XMLContent);
  XSL := LoadXMLData(XSLContent);

  XML.DocumentElement.TransformNode(XSL.DocumentElement, Result)

end;

但是会产生意外的输出:

  

比利时华夫饼5.95美元我们的两个   著名的比利时华夫饼配许多真正的枫糖浆650   Belgian Waffles(比利时华夫饼)$ 7.95   900 Berry-Berry比利时华夫饼和轻奶油9005浅比利时菜   松饼覆盖着各种各样的新鲜浆果和鞭打   900法式吐司(French Toast)$ 4.50   Bread600Homestyle Breakfast $ 6.95两个鸡蛋,培根或香肠,烤面包和   我们广受欢迎的马铃薯煎饼950


尝试2:

我在this页的“使用MSXML分析器/转换引擎”部分中找到了以下功能(注意:这是一个Delphi 5示例,但我使用的是Delphi 2007)。

function DoTransform(const xml, xsl : string ): string;
var
  XMLDoc : IXMLDOMDocument;
  XSLDoc : IXMLDOMDocument;
  Template : IXSLTemplate;
  Processor : IXSLProcessor;
begin
  Result := '';
  try
    XMLDoc := CoFreeThreadedDOMDocument30.Create;
    XSLDoc := CoFreeThreadedDOMDocument30.Create;
    XMLDoc.load(xml);
    XSLDoc.load(xsl);
    Template := CoXSLTemplate30.Create;
    Template.stylesheet := XSLDoc;
    Processor := Template.createProcessor;
    Processor.input := XMLDoc;
    Processor.transform;
    result :=  Processor.output;
  finally
    XMLDoc := nil;
    XSLDoc := nil;
  end;
end;

我已经导入了Microsoft XML类型库...

  

组件->导入组件->导入类型库->下一步-> Microsoft XML,v6.0

...并在uses子句中添加了MSXML2_TLB,但随后发生了其他一些错误:

  

E2003未声明的标识符:'CoFreeThreadedDOMDocument30'

     

E2003未声明的标识符:'CoXSLTemplate30'

我已将CoFreeThreadedDOMDocument30切换为CoFreeThreadedDOMDocument60,将CoXSLTemplate30切换为CoXSLTemplate60,现在它可以正确编译了。

在运行时,在此行:

Template.stylesheet := XSLDoc;

它引发以下异常(意大利语):

  

不包含任何基本文件。 Il foglio di   不支持文档格式的XML   Corretto。

用英语应该是这样的:

  

样式表不包含文档元素。样式表是   为空,或者它可能是格式错误的XML文档。

我已经对其他示例文件进行了测试,并且错误始终相同,并且我不知道这可能是问题所在。

我是走对路还是有更好的方法来做我需要的事?

3 个答案:

答案 0 :(得分:0)

我有以下有效的代码。假设文件包含XSLT,但是应该易于更改。

这是很久以前写的,我很着急。因此,可能还有一些改进的余地。希望对您有所帮助。

uses
  Windows, ComObj, XMLDoc, msxmldom, msxml;

function DOMToMSDom(const Doc: IDOMDocument): IXMLDOMDocument3;
begin
  Result := ((Doc as IXMLDOMNodeRef).GetXMLDOMNode as IXMLDOMDocument3);
end;

function TransformXMLDocWithXSLTFile(const Doc: XMLIntf.IXMLDocument; const StyleSheetLocation: string; var TransformedData, Error: string): Boolean;
var
  MsxmlDoc: IXMLDOMDocument3;
  xslStyle : IXMLDOMDocument;
begin
  Result := False;
  if not FileExists(StyleSheetLocation) then 
  begin
    Error := 'Specified XSLT stylesheet file does not exist: ' + StyleSheetLocation;
    Exit;
  end;
  try
    MsxmlDoc := DOMToMSDom(Doc.DOMDocument);
    xslStyle := CoDOMDocument60.Create;
    xslStyle.load(StyleSheetLocation);
    IXMLDOMDocument3(xslStyle).setProperty('AllowXsltScript', True);
    TransformedData := MsxmlDoc.transformNode(xslStyle);
    Result := True;
  except
    on E: Exception do 
    begin
      Error := E.Message;
    end;
  end;
end;

答案 1 :(得分:0)

有一些问题;

您的XSL没有样式表,输出或根模板。它需要像这样:

<?xml version="1.0" encoding="UTF-8" ?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">

    <xsl:output method="html" encoding="UTF-8" />

    <xsl:template match="/">
        <html xsl:version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
            <body style="font-family:Arial;font-size:12pt;background-color:#EEEEEE">
                <xsl:for-each select="breakfast_menu/food">
                    <div style="background-color:teal;color:white;padding:4px">
                        <span style="font-weight:bold">
                            <xsl:value-of select="name"/> - </span>
                        <xsl:value-of select="price"/>
                    </div>
                    <div style="margin-left:20px;margin-bottom:1em;font-size:10pt">
                        <p>
                            <xsl:value-of select="description"/>
                            <span style="font-style:italic"> (<xsl:value-of select="calories"/> calories per serving)</span>
                        </p>
                    </div>
                </xsl:for-each>
            </body>
        </html>
    </xsl:template>
</xsl:stylesheet>

在您的delphi代码中,因为您正在加载字符串,所以应使用.loadXML而不是.load

    XMLDoc := CoFreeThreadedDOMDocument60.Create;
    XSLDoc := CoFreeThreadedDOMDocument60.Create;
    XMLDoc.loadXML(xml);
    XSLDoc.loadXML(xsl);
    
    Template := CoXSLTemplate60.Create;
    Template.stylesheet := XSLDoc;
    Processor := Template.createProcessor;
    Processor.input := XMLDoc;
    Processor.transform;
    s :=  Processor.output;

在执行.load或.loadXML之后,您可以查看parseerror来检查发生了什么事情(如果遇到问题)

xsldoc.parseError.errorCode;  //will be 0 if all is well
xsldoc.parseError.reason; 

答案 2 :(得分:0)

这是我在 Delphi 2007 Delphi XE7 上测试的解决方案。

uses
  msxml; 

function Transform(const AXMLContent : string; const AXSLContent : string) : string;
var
  XML : IXMLDOMDocument;
  XSL : IXMLDOMDocument;
begin
  XML := CoDOMDocument.Create;
  XML.loadXML(AXMLContent);

  XSL := CoDOMDocument.Create;
  XSL.loadXML(AXSLContent);

  Result := XML.TransformNode(XSL);
end;

picture of the resulting styled xml

生成的HTML代码:

<html>
<body style="font-family:Arial;font-size:12pt;background-color:#EEEEEE">
<div style="background-color:teal;color:white;padding:4px"><span style="font-weight:bold">Belgian Waffles - </span>$5.95</div>
<div style="margin-left:20px;margin-bottom:1em;font-size:10pt">
<p>Two of our famous Belgian Waffles with plenty of real maple syrup<span style="font-style:italic"> (650 calories per serving)</span></p>
</div>
<div style="background-color:teal;color:white;padding:4px"><span style="font-weight:bold">Strawberry Belgian Waffles - </span>$7.95</div>
<div style="margin-left:20px;margin-bottom:1em;font-size:10pt">
<p>Light Belgian waffles covered with strawberries and whipped cream<span style="font-style:italic"> (900 calories per serving)</span></p>
</div>
<div style="background-color:teal;color:white;padding:4px"><span style="font-weight:bold">Berry-Berry Belgian Waffles - </span>$8.95</div>
<div style="margin-left:20px;margin-bottom:1em;font-size:10pt">
<p>Light Belgian waffles covered with an assortment of fresh berries and whipped cream<span style="font-style:italic"> (900 calories per serving)</span></p>
</div>
<div style="background-color:teal;color:white;padding:4px"><span style="font-weight:bold">French Toast - </span>$4.50</div>
<div style="margin-left:20px;margin-bottom:1em;font-size:10pt">
<p>Thick slices made from our homemade sourdough bread<span style="font-style:italic"> (600 calories per serving)</span></p>
</div>
<div style="background-color:teal;color:white;padding:4px"><span style="font-weight:bold">Homestyle Breakfast - </span>$6.95</div>
<div style="margin-left:20px;margin-bottom:1em;font-size:10pt">
<p>Two eggs, bacon or sausage, toast, and our ever-popular hash browns<span style="font-style:italic"> (950 calories per serving)</span></p>
</div>
</body>
</html>

为了将结果字符串显示到TWebBrowser中,我使用了以下代码:

procedure LoadHTMLCode(AWebBrowser : TWebBrowser; const AHTMLCode: string);
var
  Doc: Variant;
begin
  if not Assigned(AWebBrowser.Document) then
    AWebBrowser.Navigate('about:blank');

  Doc := AWebBrowser.Document;
  Doc.Clear;
  Doc.Write(AHTMLCode);
  Doc.Close;
end;

...

var
  XMLContent : string;
  XLSContent : string;
  HTMLCode : string;
begin
  //loading XML content
  XMLContent := ...;

  //loading XLS content
  XLSContent := ...;
 
  //transforming
  HTMLCode := Transform(XMLContent, XLSContent);

  //displaying
  LoadHTMLCode(WebBrowser1, HTMLCode);  
end;