从XML文件中删除样式表

Question

我需要从input.xml文件中删除样式表行：

<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="class.xsl"?>
<class>
<student>Jack</student>
<student>Harry</student>
<student>Rebecca</student>
<teacher>Mr. Bean</teacher>
</class>

预期结果：

<?xml version="1.0" encoding="UTF-8"?>
<class>
<student>Jack</student>
<student>Harry</student>
<student>Rebecca</student>
<teacher>Mr. Bean</teacher>
</class>

我想当它从<?xml-stylesheet开始时，我可以删除整行，但我更喜欢找到一个优雅的解决方案。。。

我已经将XML加载到IXMLDocument中，但找不到任何删除<?xml-stylesheet type="text/xsl" href="class.xsl"?>行的函数：

uses
XMLDoc,
XMLIntf;
procedure TForm1.Button1Click(Sender: TObject);
var
Doc : IXMLDocument;
begin
Doc := NewXMLDocument();
Doc.LoadFromFile('.input.xml');
...
Doc.SaveToFile('.output.xml');
end;

Answer 1

您可以使用ChildNodes.Delete函数来删除节点。在这个例子中，我使用OmniXML作为供应商(以避免必须初始化COM(：

program SO60488378;
{$APPTYPE CONSOLE}

{$R *.res}
uses
Xml.XmlDom,
Xml.omnixmldom,
XMLDoc,
XMLIntf,
System.SysUtils;
var
XMLinput : String;
Doc      : IXMLDocument;
begin
XMLinput := '<?xml version="1.0" encoding="UTF-8"?>'+#13#10+
'<?xml-stylesheet type="text/xsl" href="class.xsl"?>'+#13#10+
'<class>'+#13#10+
'    <student>Jack</student>'+#13#10+
'    <student>Harry</student>'+#13#10+
'     <student>Rebecca</student>'+#13#10+
'    <teacher>Mr. Bean</teacher>'+#13#10+
'</class>'+#13#10;
try
DefaultDOMVendor := sOmniXmlVendor;
Doc := NewXMLDocument();
Doc.LoadFromXML(XMLInput);
// delete second node from root
Doc.ChildNodes.Delete(1);
Writeln(FormatXMLData(Doc.XML.Text));
except
on E: Exception do
Writeln(E.ClassName, ': ', E.Message);
end;
Readln;
end.

输出：

<?xml version="1.0"?>
<class>
<student>Jack</student>
<student>Harry</student>
<student>Rebecca</student>
<teacher>Mr. Bean</teacher>
</class>

编辑：添加@PeterWolf:建议的解决方案

Doc.LoadFromXML(XMLInput);
// loop all root nodes and delete first xml-stylesheet node
// if you want to delete ALL stylesheet nodes, just inverse the loop and remove the break statement
for Index := 0 to Doc.ChildNodes.Count-1 do
begin
Node := Doc.ChildNodes[Index];
if (Node.NodeType = ntProcessingInstr) and (Node.NodeName = 'xml-stylesheet') then
begin
Doc.ChildNodes.Delete(Index);
Break;
end;
end;
Writeln(FormatXMLData(Doc.XML.Text));

Answer 2

RegEx前往救援。

procedure TForm1.btnDoItClick(Sender: TObject);
var sXML : String;
begin
// Uses System.RegularExpressions;
sXML := memoXML.Text; // or load it from file
sXML := Tregex.Replace(sXML, '[n*](?=<?xml-stylesheet)(.*)?>', '');
memoXML.Text := sXML; // or save it to file
end;