Better way to browse XML nodes? - c#

I'm playing with an imported XML file and using XMLDocument I'm wondering if there is a better way to do the same thing.
Basically root contains MHZ nodes and each MHZ contains several devices and one name.
I want to count every MHZ nodes and display the number of devices in each MHZ :
String xmlName = "tts.xml";
XmlDocument readDoc = new XmlDocument();
readDoc.Load(xmlName);
int fileNb = readDoc.SelectNodes("//MHZ").Count;
Console.WriteLine("MHZ number : "+fileNb);
for (int i = 0; i < fileNb; i++)
{
int deviceNb = readDoc.SelectNodes("//MHZ[" +(i+1)+ "]/device").Count;
Console.WriteLine(deviceNb);
}

If you're using .NET 3.5 or later, I'd use LINQ to XML:
var doc = XDocument.Load(xmlName);
var mhzs = doc.Descendants("MHZ");
Console.WriteLine("Count of MHZ: {0}", mhz.Count());
foreach (var mhz in mhzs)
{
Console.WriteLine(mhz.Elements("device").Count());
}

Have you had a look at Linq to XML
for more info check here
http://msdn.microsoft.com/en-us/library/bb387098.aspx

Create serializable objects and then deserialize your xml into a list of the objects. This way you can stay true to OOP.
[DataContract]
public class Device
{
[DataMember]
public string Property { get; set; }
}
Or look at: DataContract XML serialization and XML attributes or How to Deserialize XML document

In some cases I create object(s) that represents the structure of the XML and deserialize the XML to these object(s) This gives me a much better way of looking at the data, validating and iterating through collections of data.

XMLDocument is easy to use as your are already using it. Also it's worth to look at XPath

Related

XML Serialization different elementName for same object

I have the following Model in ASP.Net Core
[Serializable]
[XmlRoot(ElementName = "CREDIT")]
public class Credit
{
[XmlElement(ElementName = "D_numbern")]
public string Number get; set; }
}
I did the serialization with StringWriter, the problem I should get XML like that
<CREDITS>
<CREDIT ID="1">
<D_number1>06</D_number1>
</CREDIT>
<CREDIT ID="2">
<D_number2>06</D_number2>
</CREDIT>
</CREDITS>
I didn't find a solution how to make n dynamic for each credit .
thanks in advance for any assistance.
What you're after isn't something that XmlSerializer supports, and frankly it is a bad design for xml generally; not only is it redundant (xml is ordered: there's no need to tell it that you're item 1/2/3), but it is actively hostile to most xml tooling, including serializers, schema validators, etc.
My strong suggestion is to rethink the xml you want, or challenge the requirements if it isn't your idea. If the D_number42 will always match the ID="42" that is the parent, frankly the suffix serves absolutely no purpose. If it is a different number that only looks the same in these examples by coincidence, then: <D_number someattribute="42">06</D_number>
But if you must do this, you'll have to do it manually, via XDocument, XmlDocument, or XmlWriter.
as an example using XmlWriter:
static void WriteCredit(XmlWriter xml, string id, string number)
{
xml.WriteStartElement("CREDITS");
xml.WriteStartElement("CREDIT");
xml.WriteAttributeString("ID", id);
xml.WriteElementString("D_number" + id, number);
xml.WriteEndElement();
xml.WriteEndElement();
}
usage that writes to the console:
using (var xml = XmlWriter.Create(Console.Out))
{
WriteCredit(xml, "1", "06");
}

Reading a Text File that has XML data C# [duplicate]

How do I read and parse an XML file in C#?
XmlDocument to read an XML from string or from file.
using System.Xml;
XmlDocument doc = new XmlDocument();
doc.Load("c:\\temp.xml");
or
doc.LoadXml("<xml>something</xml>");
then find a node below it ie like this
XmlNode node = doc.DocumentElement.SelectSingleNode("/book/title");
or
foreach(XmlNode node in doc.DocumentElement.ChildNodes){
string text = node.InnerText; //or loop through its children as well
}
then read the text inside that node like this
string text = node.InnerText;
or read an attribute
string attr = node.Attributes["theattributename"]?.InnerText
Always check for null on Attributes["something"] since it will be null if the attribute does not exist.
LINQ to XML Example:
// Loading from a file, you can also load from a stream
var xml = XDocument.Load(#"C:\contacts.xml");
// Query the data and write out a subset of contacts
var query = from c in xml.Root.Descendants("contact")
where (int)c.Attribute("id") < 4
select c.Element("firstName").Value + " " +
c.Element("lastName").Value;
foreach (string name in query)
{
Console.WriteLine("Contact's Full Name: {0}", name);
}
Reference: LINQ to XML at MSDN
Here's an application I wrote for reading xml sitemaps:
using System;
using System.Collections.Generic;
using System.Windows.Forms;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Data;
using System.Xml;
namespace SiteMapReader
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Please Enter the Location of the file");
// get the location we want to get the sitemaps from
string dirLoc = Console.ReadLine();
// get all the sitemaps
string[] sitemaps = Directory.GetFiles(dirLoc);
StreamWriter sw = new StreamWriter(Application.StartupPath + #"\locs.txt", true);
// loop through each file
foreach (string sitemap in sitemaps)
{
try
{
// new xdoc instance
XmlDocument xDoc = new XmlDocument();
//load up the xml from the location
xDoc.Load(sitemap);
// cycle through each child noed
foreach (XmlNode node in xDoc.DocumentElement.ChildNodes)
{
// first node is the url ... have to go to nexted loc node
foreach (XmlNode locNode in node)
{
// thereare a couple child nodes here so only take data from node named loc
if (locNode.Name == "loc")
{
// get the content of the loc node
string loc = locNode.InnerText;
// write it to the console so you can see its working
Console.WriteLine(loc + Environment.NewLine);
// write it to the file
sw.Write(loc + Environment.NewLine);
}
}
}
}
catch { }
}
Console.WriteLine("All Done :-)");
Console.ReadLine();
}
static void readSitemap()
{
}
}
}
Code on Paste Bin
http://pastebin.com/yK7cSNeY
There are lots of way, some:
XmlSerializer. use a class with the target schema
you want to read - use XmlSerializer
to get the data in an Xml loaded into
an instance of the class.
Linq 2 xml
XmlTextReader.
XmlDocument
XPathDocument (read-only access)
You could use a DataSet to read XML strings.
var xmlString = File.ReadAllText(FILE_PATH);
var stringReader = new StringReader(xmlString);
var dsSet = new DataSet();
dsSet.ReadXml(stringReader);
Posting this for the sake of information.
You can either:
Use XmlSerializer class
Use XmlDocument class
Examples are on the msdn pages provided
Linq to XML.
Also, VB.NET has much better xml parsing support via the compiler than C#. If you have the option and the desire, check it out.
Check out XmlTextReader class for instance.
There are different ways, depending on where you want to get.
XmlDocument is lighter than XDocument, but if you wish to verify minimalistically that a string contains XML, then regular expression is possibly the fastest and lightest choice you can make. For example, I have implemented Smoke Tests with SpecFlow for my API and I wish to test if one of the results in any valid XML - then I would use a regular expression. But if I need to extract values from this XML, then I would parse it with XDocument to do it faster and with less code. Or I would use XmlDocument if I have to work with a big XML (and sometimes I work with XML's that are around 1M lines, even more); then I could even read it line by line. Why? Try opening more than 800MB in private bytes in Visual Studio; even on production you should not have objects bigger than 2GB. You can with a twerk, but you should not. If you would have to parse a document, which contains A LOT of lines, then this documents would probably be CSV.
I have written this comment, because I see a lof of examples with XDocument. XDocument is not good for big documents, or when you only want to verify if there the content is XML valid. If you wish to check if the XML itself makes sense, then you need Schema.
I also downvoted the suggested answer, because I believe it needs the above information inside itself. Imagine I need to verify if 200M of XML, 10 times an hour, is valid XML. XDocument will waste a lof of resources.
prasanna venkatesh also states you could try filling the string to a dataset, it will indicate valid XML as well.
public void ReadXmlFile()
{
string path = HttpContext.Current.Server.MapPath("~/App_Data"); // Finds the location of App_Data on server.
XmlTextReader reader = new XmlTextReader(System.IO.Path.Combine(path, "XMLFile7.xml")); //Combines the location of App_Data and the file name
while (reader.Read())
{
switch (reader.NodeType)
{
case XmlNodeType.Element:
break;
case XmlNodeType.Text:
columnNames.Add(reader.Value);
break;
case XmlNodeType.EndElement:
break;
}
}
}
You can avoid the first statement and just specify the path name in constructor of XmlTextReader.
If you want to retrive a particular value from an XML file
XmlDocument _LocalInfo_Xml = new XmlDocument();
_LocalInfo_Xml.Load(fileName);
XmlElement _XmlElement;
_XmlElement = _LocalInfo_Xml.GetElementsByTagName("UserId")[0] as XmlElement;
string Value = _XmlElement.InnerText;
Here is another approach using Cinchoo ETL - an open source library to parse xml file with few lines of code.
using (var r = ChoXmlReader<Item>.LoadText(xml)
.WithXPath("//item")
)
{
foreach (var rec in r)
rec.Print();
}
public class Item
{
public string Name { get; set; }
public string ProtectionLevel { get; set; }
public string Description { get; set; }
}
Sample fiddle: https://dotnetfiddle.net/otYq5j
Disclaimer: I'm author of this library.

Read multiple XML files into a XML class structure

I would like to Read and Deserialize more than one XML file into my XML class structure given a list of strings consisting of file names.
Obviously when reading ONE xml file, you can go like this:
XmlRoot file = null;
XmlSerializer ser = new XmlSerializer(typeof(XmlRoot));
using (XmlReader read = XmlReader.Create(FileName))
{
file = (XmlRoot)ser.Deserialize(read);
{
Which will deserialize the XML file into the class structure?
It is not possible to have a list with file names and use a foreach loop to iterate over them, reading and deserializing one by one as it would theoretically result into multiple root elements being read, deserialized and replicated in the class structure.
So in general I would like to deserialize each file and append the required master elements to a root object.
Does anyone know how to accomplish this? It would be of great help.
Thanks in advance!
PS: Excuse me for my English, as I am not a native speaker. If you need further information, just tell me!
I managed to solve the problem for myself.
First i created a XDocument for the first file i read, afterwards i iterate through the other documents creating a new XDocument for every xml file and try to get the elements after the root (Language in my case) and add it to the root of the XDocument created outside the loop.
XDocument lDoc = new XDocument();
int counter = 0;
foreach (var fileName in multipleFileNames)
{
try
{
counter++;
if (lCounter <= 1)
{
doc = XDocument.Load(fileName);
}
else
{
XDocument doc2 = XDocument.Load(fileName);
IEnumerable<XElement> elements = doc2.Element("Language")
.Elements();
doc.Root.Add(elements);
}
}
return Deserialize(lDoc);
Afterwards i call the Deserialize method, deserializing my created XDocument like this:
public static XmlLanguage Deserialize(XDocument doc)
{
XmlSerializer ser = new XmlSerializer(typeof(XmlLanguage));
return (XmlLanguage)ser.Deserialize(doc.CreateReader());
}

Parsing XML using C# [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Amazon Marketplace XML parsing
I am new to parsing XML in C# and I have some data from Amazon MWS library that is displayed below. I need to parse out various ItemAttributes such as ItemDimensions. I am use to JSON responses so I am not sure how to apply this to XML. Would it be possible from someone to point me in the right direction? I have Googled XML Parsing with C# but not valuable results were found to help me complete my tasks.
<GetMatchingProductResponse xmlns="http://mws.amazonservices.com/schema/Products/2011-10-01">
<GetMatchingProductResult ASIN="1430225491" status="Success">
<Product>
<Identifiers>
<MarketplaceASIN>
<MarketplaceId>ATVPDKIKX0DER</MarketplaceId>
<ASIN>1430225491</ASIN>
</MarketplaceASIN>
</Identifiers>
<AttributeSets>
<ns2:ItemAttributes xml:lang="en-US">
<ns2:Author>Troelsen, Andrew</ns2:Author>
<ns2:Binding>Paperback</ns2:Binding>
<ns2:Brand>Apress</ns2:Brand>
<ns2:Edition>5</ns2:Edition>
<ns2:ItemDimensions>
<ns2:Height Units="inches">9.21</ns2:Height>
<ns2:Length Units="inches">7.48</ns2:Length>
<ns2:Width Units="inches">2.52</ns2:Width>
<ns2:Weight Units="pounds">5.80</ns2:Weight>
</ns2:ItemDimensions>
<ns2:IsAutographed>false</ns2:IsAutographed>
<ns2:IsEligibleForTradeIn>true</ns2:IsEligibleForTradeIn>
<ns2:IsMemorabilia>false</ns2:IsMemorabilia>
<ns2:Label>Apress</ns2:Label>
<ns2:Languages>
<ns2:Language>
<ns2:Name>english</ns2:Name>
<ns2:Type>Unknown</ns2:Type>
</ns2:Language>
<ns2:Language>
<ns2:Name>english</ns2:Name>
<ns2:Type>Original Language</ns2:Type>
</ns2:Language>
<ns2:Language>
<ns2:Name>english</ns2:Name>
<ns2:Type>Published</ns2:Type>
</ns2:Language>
</ns2:Languages>
<ns2:ListPrice>
<ns2:Amount>59.99</ns2:Amount>
<ns2:CurrencyCode>USD</ns2:CurrencyCode>
</ns2:ListPrice>
<ns2:Manufacturer>Apress</ns2:Manufacturer>
<ns2:NumberOfItems>1</ns2:NumberOfItems>
<ns2:NumberOfPages>1752</ns2:NumberOfPages>
<ns2:PackageDimensions>
<ns2:Height Units="inches">2.60</ns2:Height>
<ns2:Length Units="inches">9.20</ns2:Length>
<ns2:Width Units="inches">7.50</ns2:Width>
<ns2:Weight Units="pounds">5.80</ns2:Weight>
</ns2:PackageDimensions>
<ns2:PartNumber>9781430225492</ns2:PartNumber>
<ns2:ProductGroup>Book</ns2:ProductGroup>
<ns2:ProductTypeName>ABIS_BOOK</ns2:ProductTypeName>
<ns2:PublicationDate>2010-05-14</ns2:PublicationDate>
<ns2:Publisher>Apress</ns2:Publisher>
<ns2:SmallImage>
<ns2:URL>http://ecx.images-amazon.com/images/I/51h9Sju5NKL._SL75_.jpg</ns2:URL>
<ns2:Height Units="pixels">75</ns2:Height>
<ns2:Width Units="pixels">61</ns2:Width>
</ns2:SmallImage>
<ns2:Studio>Apress</ns2:Studio>
<ns2:Title>Pro C# 2010 and the .NET 4 Platform</ns2:Title>
</ns2:ItemAttributes>
</AttributeSets>
<Relationships/>
<SalesRankings>
<SalesRank>
<ProductCategoryId>book_display_on_website</ProductCategoryId>
<Rank>43011</Rank>
</SalesRank>
<SalesRank>
<ProductCategoryId>697342</ProductCategoryId>
<Rank>36</Rank>
</SalesRank>
<SalesRank>
<ProductCategoryId>3967</ProductCategoryId>
<Rank>53</Rank>
</SalesRank>
<SalesRank>
<ProductCategoryId>4013</ProductCategoryId>
<Rank>83</Rank>
</SalesRank>
</SalesRankings>
</Product>
</GetMatchingProductResult>
<ResponseMetadata>
<RequestId>440cdde0-fa76-4c48-bdd1-d51a3b467823</RequestId>
</ResponseMetadata>
</GetMatchingProductResponse>
I find "Linq To Xml" easier to use
var xDoc = XDocument.Parse(xml); //or XDocument.Load(filename);
XNamespace ns = "http://mws.amazonservices.com/schema/Products/2011-10-01";
var items = xDoc.Descendants(ns + "ItemAttributes")
.Select(x => new
{
Author = x.Element(ns + "Author").Value,
Brand = x.Element(ns + "Brand").Value,
Dimesions = x.Element(ns+"ItemDimensions").Descendants()
.Select(dim=>new{
Type = dim.Name.LocalName,
Unit = dim.Attribute("Units").Value,
Value = dim.Value
})
.ToList()
})
.ToList();
You could reinvent the wheel, or you could use Amazon's wheel (see #George Duckett's answer for the direct link):
Amazon Marketplace API
One option to address your question: if you want a tool that will enable you to work with your xml file, I would look at xsd.exe. MSDN for xsd.exe
This tool is able to generate classes from xml.
Otherwise, you can create a parser from the XDocument class that will allow you to use linq to build a parser such as #L.B noted in his post.
You have not made clear exactly what you need from the XML, so I cannot give you an objective answer. I'll begin by stating that there are many different ways to parse XML using .Net (and C# in your case, albeit they are similar with VB and C#).
The first one that I would look into is actually modeling your XML Data into .Net objects, more specifically, POCOs. To that class model you could add attributes that would bind or relate them to the XML and then all you'd need to do is pass the data and the class to a XML deserializer.
Now, if you don't need to retrieve the whole object, you can either use XDocument or XmlDocument. The fun part of XDocument is that its syntax in LINQ friendly, so you can parse you XML very simply.
XmlDocument is more old-style sequential method invocation, but achieves the same thing.
Let me illustrate. Consider a simpler XML, for simplicity sake's:
<body>
<h1>This is a text.</h1>
<p class="SomeClass">This is a paragraph</p>
</body>
(see what I did there? That HTML is a valid XML!)
I. Using A Deserializer:
First you model the classes:
[XmlRoot]
public class body
{
[XmlElement]
public h1 h1 { get; set; }
[XmlElement]
public p p { get; set; }
}
public class h1
{
[XmlText]
public string innerXML { get; set; }
}
public class p
{
[XmlAttribute]
public string id { get; set; }
[XmlText]
public string innerXML { get; set; }
}
Once you have your class model, you call the serializer.
void Main()
{
string xml =
#"<body>
<h1>This is a text.</h1>
<p id=""SomeId"">This is a paragraph</p>
</body>";
// Creates a stream that reads from the string
MemoryStream stream = new MemoryStream();
StreamWriter writer = new StreamWriter(stream);
writer.Write(xml);
writer.Flush();
stream.Position = 0;
// Check the classes below before proceding.
XmlSerializer serializer = new XmlSerializer(typeof(body));
var obj = (body)serializer.Deserialize(stream);
// Check obj here with the debugger. All fields are filled.
}
II. Using XDocument
The example above makes for a very neat code, since you access everything typed. However, it demands a lot of setup work since you must model the classes. Maybe some simpler will suffice in your case. Let's say you want to get the attribute of the p element:
void Main()
{
string xml =
#"<body>
<h1>This is a text.</h1>
<p id=""SomeId"">This is a paragraph</p>
</body>";
// Creates a stream that reads from the string
MemoryStream stream = new MemoryStream();
StreamWriter writer = new StreamWriter(stream);
writer.Write(xml);
writer.Flush();
stream.Position = 0;
// Using XDocument
var pAttrib = XDocument.Load(stream).Element("body").Element("p").Attribute("id").Value;
Console.Writeline(pAttrib);
}
Simple, huh? You can do more complex stuff throwing LINQ there... Let's try to find the element with id named "SomeId":
void Main()
{
string xml =
#"<body>
<h1>This is a text.</h1>
<p id=""SomeId"">This is a paragraph</p>
</body>";
// Creates a stream that reads from the string
MemoryStream stream = new MemoryStream();
StreamWriter writer = new StreamWriter(stream);
writer.Write(xml);
writer.Flush();
stream.Position = 0;
// Using XDocument
var doc = XDocument.Load(stream);
var found = from body in doc.Elements("body")
from elem in body.Elements()
from attrib in elem.Attributes()
where attrib.Name == "id" && attrib.Value == "SomeId"
select elem;
foreach (var e in found) Console.WriteLine(e);
}
Hope it helps.

C# newbie: reading repetitive XML to memory

I'm new to C#. I'm building an application that persists an XML file with a list of elements. The structure of my XML file is as follows:
<Elements>
<Element>
<Name>Value</Name>
<Type>Value</Type>
<Color>Value</Color>
</Element>
<Element>
<Name>Value</Name>
<Type>Value</Type>
<Color>Value</Color>
</Element>
<Element>
<Name>Value</Name>
<Type>Value</Type>
<Color>Value</Color>
</Element>
</Elements>
I have < 100 of those items, and it's a single list (so I'm considering a DB solution to be overkill, even SQLite). When my application loads, I want to read this list of elements to memory. At present, after browsing the web a bit, I'm using XmlTextReader.
However, and maybe I'm using it in the wrong way, I read the data tag-by-tag, and thus expect the tags to be in a certain order (otherwise the code will be messy). What I would like to do is read complete "Element" structures and extract tags from them by name. I'm sure it's possible, but how?
To clarify, the main difference is that the way I'm using XmlTextReader today, it's not tolerant to scenarios such as wrong order of tags (e.g. Type comes before Name in a certain Element).
What's the best practice for loading such structures to memory in C#?
It's really easy to do in LINQ to XML. Are you using .NET 3.5? Here's a sample:
using System;
using System.Xml.Linq;
using System.Linq;
class Test
{
[STAThread]
static void Main()
{
XDocument document = XDocument.Load("test.xml");
var items = document.Root
.Elements("Element")
.Select(element => new {
Name = (string)element.Element("Name"),
Type = (string)element.Element("Type"),
Color = (string)element.Element("Color")})
.ToList();
foreach (var x in items)
{
Console.WriteLine(x);
}
}
}
You probably want to create your own data structure to hold each element, but you just need to change the "Select" call to use that.
Any particular reason you're not using XmlDocument?
XmlDocument myDoc = new XmlDocument()
myDoc.Load(fileName);
foreach(XmlElement elem in myDoc.SelectNodes("Elements/Element"))
{
XmlNode nodeName = elem.SelectSingleNode("Name/text()");
XmlNode nodeType = elem.SelectSingleNode("Type/text()");
XmlNode nodeColor = elem.SelectSingleNode("Color/text()");
string name = nodeName!=null ? nodeName.Value : String.Empty;
string type = nodeType!=null ? nodeType.Value : String.Empty;
string color = nodeColor!=null ? nodeColor.Value : String.Empty;
// Here you use the values for something...
}
It sounds like XDocument, and XElement might be better suited for this task. They might not have the absolute speed of XmlTextReader, but for your cases they sound like they would be appropriate and it would make dealing with fixed structures a lot easier. Parsing out elements would work like so:
XDocument xml;
foreach (XElement el in xml.Element("Elements").Elements("Element")) {
var name = el.Element("Name").Value;
// etc.
}
You can even get a bit fancier with Linq:
XDocument xml;
var collection = from el in xml.Element("Elements").Elements("Element")
select new { Name = el.Element("Name").Value,
Color = el.Element("Color").Value,
Type = el.Element("Type").Value
};
foreach (var item in collection) {
// here you can use item.Color, item.Name, etc..
}
You could use XmlSerializer class (http://msdn.microsoft.com/en-us/library/system.xml.serialization.xmlserializer.aspx)
public class Element
{
public string Name { get; set; }
public string Type { get; set; }
public string Color { get; set; }
}
class Program
{
static void Main(string[] args)
{
string xml =
#"<Elements>
<Element>
<Name>Value</Name>
<Type>Value</Type>
<Color>Value</Color>
</Element>(...)</Elements>";
XmlSerializer serializer = new XmlSerializer(typeof(Element[]), new XmlRootAttribute("Elements"));
Element[] result = (Element[])serializer.Deserialize(new StringReader(xml));}
You should check out Linq2Xml, http://www.hookedonlinq.com/LINQtoXML5MinuteOverview.ashx

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