查找和替换XML文件

Question

I have a lot of XML files that need to be edited. I need to find all instances with: Example

<Btn> 
    <sText>Hold</sText>

and add a field before it

  <Btn>//star of new fields
      <sText>Tools</sText>    
      *rest of fields*     
  </Btn> //end of added fields  
  <Btn> //start of original search
      <sText>Hold</sText>

I have read the using regex on XML is not advisable. What would be the best way to achieve a large one time operation for multiple files for something like this?

For regex I tried but with no luck to just start out with searching for the needed fields.

/<Btn>(.*?(\n))+.*?<sText>Hold</sText>/im

Using editors like notepad++,Brackets currently to edit files. Any suggestions on doing a large one time one time operation would be greatly appreciated. Doing the changes by hand in the GUI to hundreds of configs is not desirable.Just looking for an alternative route to save sanity.

Answer 1

I have an XSL approach you might like to try. XSL is great for transforming XML documents of one kind into another (amongst other things).

As I understand it, you need to find each instance of Btn and copy it to a new instance before its current location.

With this in mind, here's how I got it to work.

Test.xml file:

<?xml version="1.0" encoding="utf-8"?>
<?xml-stylesheet type="text/xsl" href="Test.xslt"?>

<Something>
  <Btn>
    <sText>Hold</sText>
    <Another>Foo</Another>
  </Btn>
  <Btn>
    <sText>Hold</sText>
  </Btn>
  <Btn>
    <sText>Hold</sText>
  </Btn>
</Something>

Note the use of the stylesheet reference, you would need to add this to the documents you wish to edit.

Test.xslt file:

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

  <xsl:output method="xml" indent="yes"/>

  <xsl:template match="/">
    <xsl:element name="Output">
      <xsl:apply-templates select="//Btn" />
    </xsl:element>
  </xsl:template>

  <xsl:template match="Btn">
    <xsl:element name="NewBtn">
      <xsl:copy-of select="current()/*" />
    </xsl:element>
    <xsl:element name="Btn">
      <xsl:copy-of select="current()/*" />
    </xsl:element>
  </xsl:template>

</xsl:stylesheet>

The output should look like this:

<?xml version="1.0" encoding="utf-8"?>
<Output>
  <NewBtn>
    <sText>Hold</sText>
    <Another>Foo</Another>
  </NewBtn>
  <Btn>
    <sText>Hold</sText>
    <Another>Foo</Another>
  </Btn>
  <NewBtn>
    <sText>Hold</sText>
  </NewBtn>
  <Btn>
    <sText>Hold</sText>
  </Btn>
  <NewBtn>
    <sText>Hold</sText>
  </NewBtn>
  <Btn>
    <sText>Hold</sText>
  </Btn>
</Output>

The newly duplicated instances of your Btn nodes are named NewBtn in this example.

Note that I've changed/added some elements here (Output, Something) in order to get valid XML.

I hope that helps!

Answer 2

You can create an object for your XML document. From there you can traverse through all of its nodes, find what you are looking for and add them to a list. When you already have the list, you can then write your logic for inserting the nodes that you want. I'm using LINQ.

public class Program
{
    static void Main(string[] args)
    {
        XDocument doc = XDocument.Load("YourXmlFile.xml");

        RootElement root = new RootElement(doc.Elements().FirstOrDefault());

        foreach (XElement item in root.GetInstances())
        {
            //--Your logic for adding the fields you want
        }

        Console.ReadLine();
    }
}

public class RootElement
{
    public List<XElement> childElements { get; set; }

    public RootElement(XElement xElement)
    {
        childElements = new List<XElement>();

        foreach (XElement e in xElement.Elements())
        {
            childElements.Add(e);
        }
    }

    public List<XElement> GetInstances()
    {
        List<XElement> instances = new List<XElement>();
        foreach (XElement item in childElements)
        {
            if (item.Name == "Btn")
            {
                IEnumerable<XElement> elements = item.Elements();
                XElement child = elements.FirstOrDefault(x => x.Name == "sText");

                if (child != null)
                {
                    if (child.Value == "Hold")
                    {
                        instances.Add(item);
                    }
                }
            }
        }

        return instances;
    }
}

Answer 3

You can try to solve it without regular expressions. For example you can use XmlReader and XmlWriter

• Read one row with XmlReader
• Check for your condition
• Skip/modify row
• Write row with XmlWriter

It's the most memory and CPU efficient solution since you don't need to load whole file to memory and XML Writer/Reader in C# are pretty fast compared to XDocument or other fancy xml parsers. Moreover it's simple so you need to mess with regexes and can contain any complicated logic you will need.