Develop Reference

Complicated XML Diff

I have been doing a lot of research on various ways to compare directories of XML files to each other, such that each "actual build" XML file has a matching "template build" XML file. These templates are going to be the actual config files for future builds, so I need to go back through the currently working config files and check for differences in data. These differences will be included as client changeable configurations for the future builds.
I have looked at the XML Diff and Patch (both GUI and VisStu forms) and tried to get differences, but it returns exceptions left and right and can never get the diffGram created. It seems that the XD&P is looking for library elements that no longer exist or have been changed in ways that break it.
Now, I am brand new to XML and LINQ, but I know this is where my answer lies. I have been thinking about creating path strings for every line such that the following xml file:
<configuration>
<title>#ClientOfficialName# Interactive Map</title>
<subtitle>Powered By Yada</subtitle>
<logo>assets/images/mainpageglobe.png</logo>
<style alpha="0.9">
<colors>0xffffff,0x777777,0x555555,0x333333,0xffffff</colors>
<font name="Verdana"/>
<titlefont name="Verdana"/>
<subtitlefont name="Verdana"/>
</style>
Would create strings like:
configuration/title/"#ClientOfficialName# Interactive Map"
configuration/subtitle/"Powered By Yada"
configuration/logo/"assets/iamges/mainpageglobe.png"
configuration/style/alpha/"0.9"
configuration/style/colors/"0xffffff,0x777777,0x555555,0x333333,0xffffff"
and so on like this.
In this manner, I can get every line from the Actual and the Template files and compare them based on "if they are of the same node path, then compare text. If text of all exact siblings does not match, put string into differenceOutput.txt".
So far this is the best concept I have come up with. If anyone can help me achieve this (through this or any other method), I would greatly appreciate it.
I currently have the directory system working no problem, I just have no idea where to start with the population of the string containers from the xml file:
static void Main(string[] args)
{
//Set Up File Paths
var actualBuildPath = #"C:\actual";
var templateBuildPath = #"C:\template";
//Output File Setups
var missingFileList = new List<string>();
var differenceList = new List<string>();
//Iterate through Template Directory checking to see if the Current Build Directory
//has everything and finding differences if they exist
foreach (var filePath in Directory.GetFiles(templateBuildPath, "*.xml", SearchOption.AllDirectories))
{
//Announce Current File
Console.WriteLine("File: {0} ", filePath);
//Make Sure file Exists in current build
if (File.Exists(filePath.Replace(templateBuildPath, actualBuildPath)))
{
//Fill in String Containers as prep for comparison
var templateBuildFormattedXmlLines = PopulateStringContainerFromXML(filePath);
var actualBuildFormattedXmlLines = PopulateStringContainerFromXML(filePath.Replace(templateBuildPath, actualBuildPath));
//COMPARISON SECTION-------------------------------------------------------
xmlFileCompare(templateBuildFormattedXmlLines, actualBuildFormattedXmlLines);
}
//Put missing file into missing file output file
else
missingFileList.Add("Missing: " + filePath.Replace(templateBuildPath, actualBuildPath));
}
//Create Output Folder and Output Files
if (!Directory.Exists(actualBuildPath + #"\Outputs"))
Directory.CreateDirectory(actualBuildPath + #"\Outputs");
File.WriteAllLines(actualBuildPath + #"\Outputs\MissingFiles.txt", missingFileList);
File.WriteAllLines(actualBuildPath + #"\Outputs\differenceList.txt", differenceList);
//Wait to close console until user interacts
Console.ReadLine();
}

Assuming all the configuration files are the same (grammatically) I would recomend to read them into a object and compare these objects, with this you have the possibility to make a finer grained comparison e.g the subtitle may be left out of the comparison.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Xml.Linq;
namespace XMLTest
{
class Program
{
static void Main(string[] args)
{
//You can use the XDocument.Load() Method to load a xml from a file path rather than a string
string xml = "<configuration><title>#ClientOfficialName# Interactive Map</title><subtitle>Powered By Yada</subtitle><logo>assets/images/mainpageglobe.png</logo><style alpha=\"0.9\"> <colors>0xffffff,0x777777,0x555555,0x333333,0xffffff</colors> <font name=\"Verdana\"/> <titlefont name=\"Verdana\"/> <subtitlefont name=\"Verdana\"/></style></configuration>";
XDocument d = XDocument.Parse(xml);
Configuration c = new Configuration();
c.Title = d.Descendants().Where(x => x.Name == "title").FirstOrDefault().Value;
c.SubTitle = d.Descendants().Where(x => x.Name == "subtitle").FirstOrDefault().Value;
c.Logo = d.Descendants().Where(x => x.Name == "logo").FirstOrDefault().Value;
Configuration.Style s = new Configuration.Style();
s.Alpha = (from attr in d.Descendants().Attributes() select attr).Where(x => x.Name == "alpha").FirstOrDefault().Value;
string tmp = d.Descendants().Where(x => x.Name == "colors").FirstOrDefault().Value;
foreach (string str in tmp.Split(','))
{
s.Colors.Add(Convert.ToInt32(str, 16));
}
s.FontName = (from attr in d.Descendants().Where(x=>x.Name =="font").Attributes() select attr).Where(x => x.Name == "name").FirstOrDefault().Value;
s.TitleFontName = (from attr in d.Descendants().Where(x => x.Name == "titlefont").Attributes() select attr).Where(x => x.Name == "name").FirstOrDefault().Value;
s.SubtitleFontName = (from attr in d.Descendants().Where(x => x.Name == "subtitlefont").Attributes() select attr).Where(x => x.Name == "name").FirstOrDefault().Value;
c.MyStyle = s;
Console.WriteLine(c.ToString());
Console.ReadKey();
}
}
public class Configuration : IComparable
{
public string Title;
public string SubTitle;
public string Logo;
public Style MyStyle;
public override string ToString()
{
return string.Format("Configuration : Title: {0}, Subtitle {1}, Logo {2}, Style: {3}",Title,SubTitle,Logo,MyStyle.ToString());
}
public class Style
{
public string Alpha;
public List<int> Colors = new List<int>();
public string FontName;
public string TitleFontName;
public string SubtitleFontName;
public override string ToString()
{
string s = "Alpha :" +Alpha;
s+= ", Colors: ";
foreach(int i in Colors){
s += string.Format("{0:x},",i);
}
s += " FontName :" + FontName;
s += " TitleFontName :" + TitleFontName;
s += " SubTitleFontName :" + SubtitleFontName;
return s;
}
}
public int CompareTo(object obj)
{
if ((obj as Configuration) == null)
{
throw new ArgumentException("Not instance of configuration");
}
//Very simple comparison, ranks by the title in the comparison object, here you could compare all the other values e.g Subtitle , logo and such to test if two instances are Equal
return String.Compare(this.Title, ((Configuration)obj).Title, true);
}
}
}
For a more Complete overview of Implementing Comparison see: https://msdn.microsoft.com/en-us/library/system.icomparable.compareto%28v=vs.110%29.aspx

XML linq need detail info on exception

I am using xml linq on my project. I am dealing with very large xml's for easy understanding purpose I have mentioned small sample xml.
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<soap:Body>
<StackOverflowReply xmlns="http://xml.stack.com/RRAND01234">
<processStatus>
<statusCode1>P</statusCode1>
<statusCode2>P</statusCode2>
<statusCode3>P</statusCode3>
<statusCode4>P</statusCode4>
</processStatus>
</StackOverflowReply>
</soap:Body>
Following is C# xml linq
XNamespace x = "http://xml.stack.com/RRAND01234";
var result = from StackOverflowReply in XDocument.Parse(Myxml).Descendants(x + "Security_AuthenticateReply")
select new
{
status1 = StackOverflowReply.Element(x + "processStatus").Element(x + "statusCode1").Value,
status2 = StackOverflowReply.Element(x + "processStatus").Element(x + "statusCode2").Value,
status3 = StackOverflowReply.Element(x + "processStatus").Element(x + "statusCode3").Value,
status4 = StackOverflowReply.Element(x + "processStatus").Element(x + "statusCode4").Value,
status5 = StackOverflowReply.Element(x + "processStatus").Element(x + "statusCode5").Value,
};
Here I am getting exception like "Object reference not set to an instance of an object.". Because the tag
<statusCode5>
was not in my xml.In this case I want to get detail exception message like "Missing tag statusCode5". Please guide me how to get this message from my exception.

There's no easy way (that I'm aware of) to find out exactly what element(s) was/were missing in a LINQ to XML statement. What you can do however is use (string) on the element to handle missing elements - but that can get tricky if you have a chain of elements.
That wouldn't work in your current code:
status5 = (string)StackOverflowReply.Element(x + "processStatus").Element(x + "statusCode5")
Becuase (string) will only work on first element, and the second one is the one that is missing.
You could change your LINQ to focus only on the subnodes, like this:
XNamespace x = "http://xml.stack.com/RRAND01234";
var result = from StackOverflowReply in XDocument.Parse(Myxml).Descendants(x + "processStatus")
select new
{
status1 = (string)StackOverflowReply.Element(x + "statusCode1"),
status2 = (string)StackOverflowReply..Element(x + "statusCode2"),
status3 = (string)StackOverflowReply..Element(x + "statusCode3"),
status4 = (string)StackOverflowReply.Element(x + "statusCode4"),
status5 = (string)StackOverflowReply.Element(x + "statusCode5"),
};
However, if your XML is complex and you have different depths (nested elements), you'll need a more robust solution to avoid a bunch of conditional operator checks or multiple queries.
I have something that might help if that is the case - I'll have to dig it up.
EDIT For More Complex XML
I've had similar challenges with some XML I have to deal with at work. In lieu of an easy way to determine what node was the offending node, and not wanting to have hideously long ternary operators, I wrote an extension method that worked recursively from the specified starting node down to the one I was looking for.
Here's a somewhat simple and contrived example to demonstrate.
<SomeXML>
<Tag1>
<Tag1Child1>Value1</Tag1Child1>
<Tag1Child2>Value2</Tag1Child2>
<Tag1Child3>Value3</Tag1Child3>
<Tag1Child4>Value4</Tag1Child4>
</Tag1>
<Tag2>
<Tag2Child1>
<Tag2Child1Child1>SomeValue1</Tag2Child1Child1>
<Tag2Child1Child2>SomeValue2</Tag2Child1Child2>
<Tag2Child1Child3>SomeValue3</Tag2Child1Child3>
<Tag2Chidl1Child4>SomeValue4</Tag2Child1Child4>
<Tag2Child1>
<Tag2Child2>
<Tag2Child2Child1>
<Tag2Child2Child1Child1 />
<Tag2Child2Child1Child2 />
</Tag2Child2>
</Tag2>
</SomeXML>
In the above XML, I had no way of knowing (prior to parsing) if any of the children elements were empty, so I after some searching and fiddling I came up with the following extension method:
public static XElement GetChildFromPath(this XElement currentElement, List<string> elementNames, int position = 0)
{
if (currentElement == null || !currentElement.HasElements)
{
return currentElement;
}
if (position == elementNames.Count - 1)
{
return currentElement.Element(elementNames[position]);
}
else
{
XElement nextElement = currentElement.Element(elementNames[position]);
return GetChildFromPath(nextElement, elmenentNames, position + 1);
}
}
Basically, the method takes the XElement its called on, plus a List<string> of the elements in path order, with the one I want as the last one, and a position (index in the list), and then works it way down the path until it finds the element in question or runs out of elements in the path. It's not as elegant as I would like it to be, but I haven't had time to refactor it any.
I would use it like this (based on the sample XML above):
MyClass myObj = (from x in XDocument.Parse(myXML).Descendants("SomeXML")
select new MyClass() {
Tag1Child1 = (string)x.GetChildFromPath(new List<string>() {
"Tag1", "Tag1Child1" }),
Tag2Child1Child4 = (string)x.GetChildFromPath(new List<string>() {
"Tag2", "Tag2Child1", "Tag2Child1Child4" }),
Tag2Child2Child1Child2 = (string)x.GetChildFromPath(new List<string>() {
"Tag2", "Tag2Child2", "Tag2Child2Child1",
"Tag2Child2Child1Child2" })
}).SingleOrDefault();
Not as elegant as I'd like it to be, but at least it allows me to parse an XML document that may have missing nodes without blowing chunks. Another option was to do something like:
Tag2Child2Child1Child1 = x.Element("Tag2") == null ?
"" : x.Element("Tag2Child2") == null ?
"" : x.Element("Tag2Child2Child1") == null ?
"" : x.Element("Tag2Child2Child1Child2") == null ?
"" : x.Element("Tag2")
.Element("Tag2Child2")
.Element("Tag2Child2Child1")
.Element("Tag2Child2Child1Child2").Value
That would get really ugly for an object that had dozens of properties.
Anyway, if this is of use to you feel free to use/adapt/modify as you need.

How to deal with non-fixed xelement?

im using a method to parse a xdocument to an object but i have a situation in this line of code:
var xElementTax = xElementXml.Element(xn + "tax");
var aux = xElementTax.Element(xn + "taxNN").Value;
In the taxNN XName the NN part is a random number, i.e: tax01, tax02, tax03 and goes on. It could be any two digit number.
How can i deal with this situation wheres i dont have a fixed tag? The only fixed part of the tag is the tax word.
Thanks.

Are you looping through all the elements of xElementTax?
If so you can just go with this:
foreach(XElement auxElement in xElementTax.Elements)
{
var aux = auxElement.Value;
// And so on
}
If you want only those which match "taxNN" you can go instead with:
foreach(XElement auxElement in xElementTax.Elements.Where(x => x.Name.ToString().StartsWith(xn + "tax"))
{
var aux = auxElement.Value;
...
}
If there's only going to be one of them you can go with:
XElement auxElement = xElementTax.Elements.Where(
x => x.Name.ToString().StartsWith(xn + "tax").FirstOrDefault();
var aux = auxElement.Value;

Parsing an UN XML file in C#

I'm trying to parse an XML file from UN website (http://www.un.org/sc/committees/1267/AQList.xml) using c#.
There is one problem I'm constantly having with this file, and that's the number of child tags varies from one <.INDIVIDUAL.> tag to another. One example is <.FORTH_NAME.> child tag.
I've tried a number of different approaches, but somehow I always seem to be stuck with the same problem, and that's different number of child tags inside <.INDIVIDUAL.> tag.
What I'm trying to achieve is to collect all the tags and their values under one <.INDIVIDUAL.> tag, and then insert only those I want into my database. If a tag is missing, for example <.FOURTH_NAME.>, than I need to insert only first three names into the database, and skip the fourth.
I've tried using Linq to XML, and here are some examples:
XDocument xdoc = XDocument.Load(path);
var tags = (from t in xdoc.Descendants("INDIVIDUALS")
from a in t.Elements("INDIVIDUAL")
select new
{
Tag = a.Name,
val = a.Value
});
foreach (var obj in tags)
{
Console.WriteLine(obj.Tag + " - " + obj.val + "\t");
//insert SQL goes here
}
or:
but this one only collects non empty FOURTH_NAME tags...
var q = (from c in xdoc.Descendants("INDIVIDUAL")
from _1 in c.Elements("FIRST_NAME")
from _2 in c.Elements("SECOND_NAME")
from _3 in c.Elements("THIRD_NAME")
from _4 in c.Elements("FOURTH_NAME")
where _1 != null && _2 != null && _3 != null && _4 != null
select new
{
_1 = c.Element("FIRST_NAME").Value,
_2 = c.Element("SECOND_NAME").Value,
_3 = c.Element("THIRD_NAME").Value,
_4 = c.Element("FOURTH_NAME").Value
});
foreach (var obj in q)
{
Console.WriteLine("Person: " + obj._1 + " - " + obj._2 + " - " + obj._3 + " - " + obj._4);
//insert SQL goes here
}
Any ideas??

Instead of calling Value on the element, consider using a string cast. LINQ to XML safely returns null if the element doesn't exist. Try the following:
var data = XElement.Load(#"http://www.un.org/sc/committees/1267/AQList.xml");
var individuals = data.Descendants("INDIVIDUAL")
.Select(i => new {
First = (string)i.Element("FIRST_NAME"),
Middle = (string)i.Element("SECOND_NAME"),
Last = (string)i.Element("THIRD_NAME")
});
If you want to be more flexible and get all of the name fields, you can do something like the following. (I'll leave the process of grouping individuals as an additional homework assignment ;-)
data.Descendants("INDIVIDUAL").Elements()
.Where (i =>i.Name.LocalName.EndsWith("_NAME" ))
.Select(i => new { FieldName= i.Name.LocalName, Value=i.Value});

Why don't you use XmlSerializer and LINQ instead ?
As explained in this answer, generate your classes by pasting in a new CS file :
menu EDIT > Paste Special > Paste XML As Classes.
Then grab your data as easily as follows :
var serializer = new XmlSerializer(typeof (CONSOLIDATED_LIST));
using (FileStream fileStream = File.OpenRead(#"..\..\aqlist.xml"))
{
var list = serializer.Deserialize(fileStream) as CONSOLIDATED_LIST;
if (list != null)
{
var enumerable = list.INDIVIDUALS.Select(s => new
{
FirstName = s.FIRST_NAME,
SecondName = s.SECOND_NAME,
ThirdName = s.THIRD_NAME,
FourthName = s.FOURTH_NAME
});
}
}
You can then specify any predicate that better suits your needs.
Going this path will be a huge time-saver and less error-prone, no need to use strings to access fields, strong typing etc ...

Parsing XML: NullReferenceException for Variable Elements

I'm getting a text string from a website and parsing it into an XDocument. I'm looking to feed the value of certain elements into a very simple object (named NWSevent). My problem is that the original string changes and the XML tree varies; sometimes there are numerous events, up to 40, sometimes there is only one, and sometimes there is only one that does not have all the characteristics. If there are no alerts, then the "event" element has a title, but no areaDesc, summary, or severity.
I have two constructors for NWSevent, one takes in a single string, the other takes in four string arguments. I'm having trouble getting around a NullReferenceException. The if statement below can't do it because there is no value to compare. I'd appreciate any help.
public static void ParseWeatherData(String xmlString)
{
String ticker = string.Empty;
XDocument root = XDocument.Parse(xmlString);
XNamespace ns = XNamespace.Get("http://www.w3.org/2005/Atom");
XNamespace nsCap = XNamespace.Get("urn:oasis:names:tc:emergency:cap:1.1");
//get list of entry elements, set conditions for title, areaDesc, etc
var xlist = root.Descendants(ns + "entry").Select(elem => new
{ //use first or default to deal with possiblity of null return
Title = elem.Descendants(ns + "title").FirstOrDefault(),
AreaDesc = elem.Descendants(nsCap + "areaDesc").FirstOrDefault(),
Severity = elem.Descendants(nsCap + "severity").FirstOrDefault(),
Summary = elem.Descendants(ns + "summary").FirstOrDefault()
});
foreach (var el in xlist) //need to address null values when no alerts
{
if (el.AreaDesc.Value != null) //causes yellow null ERROR; no value exists for el.areaDesc.value
{
String titleIn = el.Title.Value;
String areaIn = el.AreaDesc.Value;
String severityIn = el.Severity.Value;
String summaryIn = el.Summary.Value;
new Models.NWSevent(titleIn, areaIn, severityIn, summaryIn);
}
else
{
String titleIn = el.Title.Value;
new Models.NWSevent(titleIn);
}
}

Embarassing! Props to Dweeberly for pointing it out. I just need to change the if statement from
if (el.AreaDesc.Value != null){}
to if (el.AreaDesc != null){}