whats the quickest way to generate an XmlDocument object from a file. Im working on the basis that i know my xml is well formed, and ideally im looking for a method that will allow me to simply pass in a string as my file location, and return a complete XmlDocument object.
Um, XmlDocument.Load?
XmlDocument document = new XmlDocument();
document.Load(filename);
On the other hand, if you're using .NET 3.5 or higher you should strongly consider moving to LINQ to XML and XDocument instead:
XDocument doc = XDocument.Load(filename);
LINQ to XML is a much nicer XML API.
The quickest way would be:
string pathToXmlFile = //your path;
XmlDocument document = new XmlDocument();
document.Load(pathToXmlFile);
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Is there a simple method of parsing XML files in C#? If so, what?
It's very simple. I know these are standard methods, but you can create your own library to deal with that much better.
Here are some examples:
XmlDocument xmlDoc= new XmlDocument(); // Create an XML document object
xmlDoc.Load("yourXMLFile.xml"); // Load the XML document from the specified file
// Get elements
XmlNodeList girlAddress = xmlDoc.GetElementsByTagName("gAddress");
XmlNodeList girlAge = xmlDoc.GetElementsByTagName("gAge");
XmlNodeList girlCellPhoneNumber = xmlDoc.GetElementsByTagName("gPhone");
// Display the results
Console.WriteLine("Address: " + girlAddress[0].InnerText);
Console.WriteLine("Age: " + girlAge[0].InnerText);
Console.WriteLine("Phone Number: " + girlCellPhoneNumber[0].InnerText);
Also, there are some other methods to work with. For example, here. And I think there is no one best method to do this; you always need to choose it by yourself, what is most suitable for you.
I'd use LINQ to XML if you're in .NET 3.5 or higher.
Use a good XSD Schema to create a set of classes with xsd.exe and use an XmlSerializer to create a object tree out of your XML and vice versa. If you have few restrictions on your model, you could even try to create a direct mapping between you model classes and the XML with the Xml*Attributes.
There is an introductory article about XML Serialisation on MSDN.
Performance tip: Constructing an XmlSerializer is expensive. Keep a reference to your XmlSerializer instance if you intend to parse/write multiple XML files.
If you're processing a large amount of data (many megabytes) then you want to be using XmlReader to stream parse the XML.
Anything else (XPathNavigator, XElement, XmlDocument and even XmlSerializer if you keep the full generated object graph) will result in high memory usage and also a very slow load time.
Of course, if you need all the data in memory anyway, then you may not have much choice.
Use XmlTextReader, XmlReader, XmlNodeReader and the System.Xml.XPath namespace. And (XPathNavigator, XPathDocument, XPathExpression, XPathnodeIterator).
Usually XPath makes reading XML easier, which is what you might be looking for.
I have just recently been required to work on an application which involved the parsing of an XML document and I agree with Jon Galloway that the LINQ to XML based approach is, in my opinion, the best. I did however have to dig a little to find usable examples, so without further ado, here are a few!
Any comments welcome as this code works but may not be perfect and I would like to learn more about parsing XML for this project!
public void ParseXML(string filePath)
{
// create document instance using XML file path
XDocument doc = XDocument.Load(filePath);
// get the namespace to that within of the XML (xmlns="...")
XElement root = doc.Root;
XNamespace ns = root.GetDefaultNamespace();
// obtain a list of elements with specific tag
IEnumerable<XElement> elements = from c in doc.Descendants(ns + "exampleTagName") select c;
// obtain a single element with specific tag (first instance), useful if only expecting one instance of the tag in the target doc
XElement element = (from c in doc.Descendants(ns + "exampleTagName" select c).First();
// obtain an element from within an element, same as from doc
XElement embeddedElement = (from c in element.Descendants(ns + "exampleEmbeddedTagName" select c).First();
// obtain an attribute from an element
XAttribute attribute = element.Attribute("exampleAttributeName");
}
With these functions I was able to parse any element and any attribute from an XML file no problem at all!
In Addition you can use XPath selector in the following way (easy way to select specific nodes):
XmlDocument doc = new XmlDocument();
doc.Load("test.xml");
var found = doc.DocumentElement.SelectNodes("//book[#title='Barry Poter']"); // select all Book elements in whole dom, with attribute title with value 'Barry Poter'
// Retrieve your data here or change XML here:
foreach (XmlNode book in nodeList)
{
book.InnerText="The story began as it was...";
}
Console.WriteLine("Display XML:");
doc.Save(Console.Out);
the documentation
If you're using .NET 2.0, try XmlReader and its subclasses XmlTextReader, and XmlValidatingReader. They provide a fast, lightweight (memory usage, etc.), forward-only way to parse an XML file.
If you need XPath capabilities, try the XPathNavigator. If you need the entire document in memory try XmlDocument.
I'm not sure whether "best practice for parsing XML" exists. There are numerous technologies suited for different situations. Which way to use depends on the concrete scenario.
You can go with LINQ to XML, XmlReader, XPathNavigator or even regular expressions. If you elaborate your needs, I can try to give some suggestions.
You can parse the XML using this library System.Xml.Linq. Below is the sample code I used to parse a XML file
public CatSubCatList GenerateCategoryListFromProductFeedXML()
{
string path = System.Web.HttpContext.Current.Server.MapPath(_xmlFilePath);
XDocument xDoc = XDocument.Load(path);
XElement xElement = XElement.Parse(xDoc.ToString());
List<Category> lstCategory = xElement.Elements("Product").Select(d => new Category
{
Code = Convert.ToString(d.Element("CategoryCode").Value),
CategoryPath = d.Element("CategoryPath").Value,
Name = GetCateOrSubCategory(d.Element("CategoryPath").Value, 0), // Category
SubCategoryName = GetCateOrSubCategory(d.Element("CategoryPath").Value, 1) // Sub Category
}).GroupBy(x => new { x.Code, x.SubCategoryName }).Select(x => x.First()).ToList();
CatSubCatList catSubCatList = GetFinalCategoryListFromXML(lstCategory);
return catSubCatList;
}
You can use ExtendedXmlSerializer to serialize and deserialize.
Instalation
You can install ExtendedXmlSerializer from nuget or run the following command:
Install-Package ExtendedXmlSerializer
Serialization:
ExtendedXmlSerializer serializer = new ExtendedXmlSerializer();
var obj = new Message();
var xml = serializer.Serialize(obj);
Deserialization
var obj2 = serializer.Deserialize<Message>(xml);
Standard XML Serializer in .NET is very limited.
Does not support serialization of class with circular reference or class with interface property,
Does not support Dictionaries,
There is no mechanism for reading the old version of XML,
If you want create custom serializer, your class must inherit from IXmlSerializable. This means that your class will not be a POCO class,
Does not support IoC.
ExtendedXmlSerializer can do this and much more.
ExtendedXmlSerializer support .NET 4.5 or higher and .NET Core. You can integrate it with WebApi and AspCore.
You can use XmlDocument and for manipulating or retrieve data from attributes you can Linq to XML classes.
I'm freaking out with C# and XmlDocuments right now.
I need to parse XML data into another XML but I can't get special characters to work.
I'm working with XmlDocument and XmlNode.
What I tried so far:
- XmlDocument.CreateXmlDeclaration("1.0", "UTF-8", "yes");
- XmlTextWriter writer = new XmlTextWriter(outputDir + "systems.xml", Encoding.UTF8);
What I know for sure:
- The input XML is also UTF-8
- The "InnerText" value is encoded without replacing the characters
Here is some code (not all... way to much code):
XmlDocument newXml = new XmlDocument();
newXml = (XmlDocument)systemsTemplate.Clone();
newXml.CreateXmlDeclaration("1.0", "UTF-8", "yes");
newXml.SelectSingleNode("systems").RemoveAll();
foreach(XmlNode categories in exSystems.SelectNodes("root/Content/Systems/SystemLine"))
{
XmlNode categorieSystemNode = systemsTemplate.SelectSingleNode("systems/system").Clone();
categorieSystemNode.RemoveAll();
XmlNode importIdNode = systemsTemplate.SelectSingleNode("systems/system/import_id").Clone();
string import_id = categories.Attributes["nodeName"].Value;
importIdNode.InnerText = import_id;
categorieSystemNode.AppendChild(importIdNode);
[way more Nodes which I proceed like this]
}
newXml.SelectSingleNode("systems").AppendChild(newXml.ImportNode(categorieSystemNode, true));
XmlTextWriter writer = new XmlTextWriter(outputDir + "systems.xml", Encoding.UTF8);
writer.Formatting = Formatting.Indented;
newXml.Save(writer);
writer.Flush();
writer.Close();
But what I get is this as an example:
<intro><p>Whether your project [...]</intro>
Instead of this:
<intro><p>Whether your project [...] </p></intro>
I do have other non-html tags in the XML so please don't provide HTML-parsing solutions :/
I know I could replace the characters with String.Replace() but that's dirty and unsafe (and slow with around 20K lines).
I hope there is a simpler way of doing this.
Kind regards,
Eriwas
The main propose of XmlDocument is to provide an easy way to work with XML documents while making sure the outcome is a well formed document.
So, using InnerText as in your example, you let the framework encode the string and properly insert it into that document. Whenever you read that same value, it will be decoded and returned to you exactly as your original string.
But, if you want to add an XML fragment anyways, you should stick with InnerXml or ImportNode. You must be aware that could lead to a more complex document structure, and you probably would like to avoid that.
As a third possibility, you can use the CreateCDataSection to add a CDATA and add your text there.
You definitely should be away from treating that XML document as a string by trying Replace things; stick with the framework and you'll be ok.
I am working on a stylesheet and have some initial XML. However the XML is being manipulated a bit before styling and i would like to get the final XML sent into .Transform(). For instance, ...
XslCompiledTransform.Transform( xpd, xslArg, output )
...i would like to get the Xml content of xpd (as a string), so i can work on the stylesheet in other tools.
Is there a quick-and-dirty way to get this? Either in the VS2010 immediate window or as a quick C# line or two before the call to .Transform()?
EDIT: The .Transform() i'm using is
public void Transform(IXPathNavigable input,
XsltArgumentList arguments, TextWriter results);
...and xpd is an XPathDocument.
Edit: I misunderstood the intent of your question. The simple answer is to get the XML for any IXPathNavigable (which includes XPathDocument), you can do this:
string xml = xpd.CreateNavigator().OuterXml;
Below is my original answer, which explains how you could modify the XML from an XPathDocument in code before feeding it into a transform:
If xpd is an XPathDocument, you might be able to just get an XPathNavigator from the XPathDocument:
XPathNavigator xpn = xpd.CreateNavigator();
and use that to modify the XML. When you're done modifying it, you can just pass either xpn or xpd into the Transform() method. On the other hand, MSDN says that XPathDocument's CreateNavigator() creates a readonly navigator, so that may be a bit of a hitch.
If it really is readonly, you should be able to do this:
XmlDocument doc = new XmlDocument();
doc.LoadXml(xpd.CreateNavigator().OuterXml);
then use doc to modify the XML and pass doc into the transform when you're done.
I have loaded XmlDocument into memory and created new XmlElement. Now I am trying to add XmlElement to the path /report/section/hosts but I don't know how. I can add it easily below root node of XML but I cannot figure out how can I navigate deeper level in XML and just append there. In pseudo I am trying to do this:
doc.SelectNodes("/report/section/hosts").AppendChild(subRoot);
The code:
XmlDocument doc = new XmlDocument();
doc.Load("c:\\data.xml");
//host
XmlElement subRoot = doc.CreateElement("host");
//Name
XmlElement ElName = doc.CreateElement("name");
XmlText TxtName = doc.CreateTextNode("text text");
ElName.AppendChild(TxtName);
subRoot.AppendChild(ElName);
doc.DocumentElement.AppendChild(subRoot);
doc.Save("c:\\data.xml");
Try SelectSingleNode instead of SelectNodes
XmlElement parent = (XmlElement)doc.SelectSingleNode("/report/section/hosts")
parent.AppendChild(subRoot);
You are almost there. Try using SelectSingleNode instead:
XmlNode node = doc.SelectSingleNode("/report/section/hosts");
node.AppendChild(subRoot);
The SelectNodes method returns a list of Nodes.
You should use SelectSingleNode instead...
e.g. (top of my head, did not test in Visual Studio)
doc.SelectSingleNode("/report/section/hosts").AppendChild(subRoot);
You need to get a reference to an XmlElement in your doc (other than the root) to append to. There are a number of methods available on XmlDocument such as GetElementById and SelectSingleNode which do this for you in different ways, research to taste.
That said, the whole API in this area is generally regarded as a bit painful, do you have LINQ available?
Closed. This question needs to be more focused. It is not currently accepting answers.
Closed 4 years ago.
This question's answers are a community effort. Edit existing answers to improve this post. It is not currently accepting new answers or interactions.
Is there a simple method of parsing XML files in C#? If so, what?
It's very simple. I know these are standard methods, but you can create your own library to deal with that much better.
Here are some examples:
XmlDocument xmlDoc= new XmlDocument(); // Create an XML document object
xmlDoc.Load("yourXMLFile.xml"); // Load the XML document from the specified file
// Get elements
XmlNodeList girlAddress = xmlDoc.GetElementsByTagName("gAddress");
XmlNodeList girlAge = xmlDoc.GetElementsByTagName("gAge");
XmlNodeList girlCellPhoneNumber = xmlDoc.GetElementsByTagName("gPhone");
// Display the results
Console.WriteLine("Address: " + girlAddress[0].InnerText);
Console.WriteLine("Age: " + girlAge[0].InnerText);
Console.WriteLine("Phone Number: " + girlCellPhoneNumber[0].InnerText);
Also, there are some other methods to work with. For example, here. And I think there is no one best method to do this; you always need to choose it by yourself, what is most suitable for you.
I'd use LINQ to XML if you're in .NET 3.5 or higher.
Use a good XSD Schema to create a set of classes with xsd.exe and use an XmlSerializer to create a object tree out of your XML and vice versa. If you have few restrictions on your model, you could even try to create a direct mapping between you model classes and the XML with the Xml*Attributes.
There is an introductory article about XML Serialisation on MSDN.
Performance tip: Constructing an XmlSerializer is expensive. Keep a reference to your XmlSerializer instance if you intend to parse/write multiple XML files.
If you're processing a large amount of data (many megabytes) then you want to be using XmlReader to stream parse the XML.
Anything else (XPathNavigator, XElement, XmlDocument and even XmlSerializer if you keep the full generated object graph) will result in high memory usage and also a very slow load time.
Of course, if you need all the data in memory anyway, then you may not have much choice.
Use XmlTextReader, XmlReader, XmlNodeReader and the System.Xml.XPath namespace. And (XPathNavigator, XPathDocument, XPathExpression, XPathnodeIterator).
Usually XPath makes reading XML easier, which is what you might be looking for.
I have just recently been required to work on an application which involved the parsing of an XML document and I agree with Jon Galloway that the LINQ to XML based approach is, in my opinion, the best. I did however have to dig a little to find usable examples, so without further ado, here are a few!
Any comments welcome as this code works but may not be perfect and I would like to learn more about parsing XML for this project!
public void ParseXML(string filePath)
{
// create document instance using XML file path
XDocument doc = XDocument.Load(filePath);
// get the namespace to that within of the XML (xmlns="...")
XElement root = doc.Root;
XNamespace ns = root.GetDefaultNamespace();
// obtain a list of elements with specific tag
IEnumerable<XElement> elements = from c in doc.Descendants(ns + "exampleTagName") select c;
// obtain a single element with specific tag (first instance), useful if only expecting one instance of the tag in the target doc
XElement element = (from c in doc.Descendants(ns + "exampleTagName" select c).First();
// obtain an element from within an element, same as from doc
XElement embeddedElement = (from c in element.Descendants(ns + "exampleEmbeddedTagName" select c).First();
// obtain an attribute from an element
XAttribute attribute = element.Attribute("exampleAttributeName");
}
With these functions I was able to parse any element and any attribute from an XML file no problem at all!
In Addition you can use XPath selector in the following way (easy way to select specific nodes):
XmlDocument doc = new XmlDocument();
doc.Load("test.xml");
var found = doc.DocumentElement.SelectNodes("//book[#title='Barry Poter']"); // select all Book elements in whole dom, with attribute title with value 'Barry Poter'
// Retrieve your data here or change XML here:
foreach (XmlNode book in nodeList)
{
book.InnerText="The story began as it was...";
}
Console.WriteLine("Display XML:");
doc.Save(Console.Out);
the documentation
If you're using .NET 2.0, try XmlReader and its subclasses XmlTextReader, and XmlValidatingReader. They provide a fast, lightweight (memory usage, etc.), forward-only way to parse an XML file.
If you need XPath capabilities, try the XPathNavigator. If you need the entire document in memory try XmlDocument.
I'm not sure whether "best practice for parsing XML" exists. There are numerous technologies suited for different situations. Which way to use depends on the concrete scenario.
You can go with LINQ to XML, XmlReader, XPathNavigator or even regular expressions. If you elaborate your needs, I can try to give some suggestions.
You can parse the XML using this library System.Xml.Linq. Below is the sample code I used to parse a XML file
public CatSubCatList GenerateCategoryListFromProductFeedXML()
{
string path = System.Web.HttpContext.Current.Server.MapPath(_xmlFilePath);
XDocument xDoc = XDocument.Load(path);
XElement xElement = XElement.Parse(xDoc.ToString());
List<Category> lstCategory = xElement.Elements("Product").Select(d => new Category
{
Code = Convert.ToString(d.Element("CategoryCode").Value),
CategoryPath = d.Element("CategoryPath").Value,
Name = GetCateOrSubCategory(d.Element("CategoryPath").Value, 0), // Category
SubCategoryName = GetCateOrSubCategory(d.Element("CategoryPath").Value, 1) // Sub Category
}).GroupBy(x => new { x.Code, x.SubCategoryName }).Select(x => x.First()).ToList();
CatSubCatList catSubCatList = GetFinalCategoryListFromXML(lstCategory);
return catSubCatList;
}
You can use ExtendedXmlSerializer to serialize and deserialize.
Instalation
You can install ExtendedXmlSerializer from nuget or run the following command:
Install-Package ExtendedXmlSerializer
Serialization:
ExtendedXmlSerializer serializer = new ExtendedXmlSerializer();
var obj = new Message();
var xml = serializer.Serialize(obj);
Deserialization
var obj2 = serializer.Deserialize<Message>(xml);
Standard XML Serializer in .NET is very limited.
Does not support serialization of class with circular reference or class with interface property,
Does not support Dictionaries,
There is no mechanism for reading the old version of XML,
If you want create custom serializer, your class must inherit from IXmlSerializable. This means that your class will not be a POCO class,
Does not support IoC.
ExtendedXmlSerializer can do this and much more.
ExtendedXmlSerializer support .NET 4.5 or higher and .NET Core. You can integrate it with WebApi and AspCore.
You can use XmlDocument and for manipulating or retrieve data from attributes you can Linq to XML classes.