Reading XML only contents from a Log file - c#

I have a log file which stores the data in XML format. I want to read this data but the problem that I am getting is that log file is not well structured XML file. It contains some additional data like :
03/22/2013 : 13:23:32 <?xml version="1.0" encoding="UTF-8"?>
<element1>
...
...
...
</element1>
As you will notice 03/22/2013 : 13:23:32 is not allowing me to read data and throwing exception saying "Data at the root level is invalid"
I am using following method to read XML
XmlDocument doc = new XmlDocument();
doc.Load("file.log");
string xmlcontents = doc.InnerXml;
label1.Text = xmlcontents;
Please guide me through the solution as this is a rare case for me. I tried googling for a solution but couldnt succeed
Thanks

A quick hack would be to parse the log file to extract only the text found between the root xml tags, in your case, what is found between < element1> and < /element1>.
You can search for the tag < ?xml, and what comes after ?> is your root tag, and go with that. Depending on how predictable of clearly structured the log file is, you can formulate better ways of doing this, but if nothing else works, you can try this way.

var doc = new XmlDocument();
doc.LoadXml(string.Concat(File.ReadAllLines("file.log").Skip(1)));
Reorganize your XML, so the date become an Element or Attribute, if the file is too large

Maybe you should read whole file to array of lines (System.IO.File.ReadAllLines(string path)) and then join elements of array skipping first line and rest of lines which is not fragments of XML structure (assuming your sample is only part of input file).

You can skip first line
var onlyXml = (File.ReadAllLines("file.log")).Skip(1).SelectMany(l => l).ToArray();
var xmlContent = new String(onlyXml);
XmlDocument doc = new XmlDocument();
doc.LoadXml(xmlContent);
string xmlcontents = doc.InnerXml;
label1.Text = xmlcontents;
EDIT
You can get only xml between first '<' and last '>'
var text = File.ReadAllText("file.log");
var beginIndex = text.IndexOf('<');
var endIndex = text.LastIndexOf('>');
var onlyXml = text.Substring(beginIndex, endIndex - beginIndex + 1);

Related

How can I control if the tag I wanna read is in the xml file

I read tags for some information in the online dynamic xml file. But an error occurs if the tag I wanna read is not in the xml file. So, I wanna check the xml file. if the tag is in the xml file, start reading xml for the tag. if the tag is not in the xml file, not reading. I am not good in coding c#..
I use this method for reading xml file.
var xmldoc = new XmlDocument();
xmldoc.Load("http://yourwebsite.com/weather.xml");,
temperature.Text = xmldoc.SelectSingleNode("temp").InnerXml.ToString();
windspeed.Text = xmldoc.SelectSingleNode("wind_spd").InnerXml.ToString();
storm.Text = xmldoc.SelectSingleNode("storm").InnerXml.ToString();
The storm tag is sometimes to be in the xml file. Then I can read this time.
But when the storm tag is not to be in xml file, I take an error. The code doesn't work.
Shortly, I wanna do this,
if(the storm tag is in xml) //check xml file.
{
storm.Text = xmldoc.SelectSingleNode("storm").InnerXml.ToString();
}
else
{
storm.text = "";
}
check for node like this:
var node = xmldoc.SelectSingleNode("storm");
if (node != null)
{
storm.Text = xmldoc.SelectSingleNode("storm").InnerXml.ToString();
}
else
{
//node doesn't exist
}
You can use null propagation.
Something like:
temperature.Text = xmldoc.SelectSingleNode("temp")?.InnerXml.ToString();
So in case of xmldoc.SelectSingleNode("temp") returns null - temperature.Text will also be null without exception.

How to get the xml node value into a string

How to get the xml node value in a string.
i am getting This error
Data at the root level is invalid. Line 1, position 1.
error shown in this line
xmldoc.LoadXml(xmlFile);
my xml
<?xml version="1.0" encoding="utf-8" ?>
<UOM>
<!-- The selected currency used will be stored here for Code reference" -->
<ActiveCurrencyType>
<ActiveCurrency>U.S.Dollar</ActiveCurrency>
<ActiveCode>USD</ActiveCode>
<ActiveSymbol>$</ActiveSymbol>
</ActiveCurrencyType>
<!-- The selected Dimension used will be stored here for Code reference -->
<ActiveDimension>
<ActiveDimensionUOM>Inches</ActiveDimensionUOM>
<ActiveDimensionSymbol>.in</ActiveDimensionSymbol>
</ActiveDimension>
<!-- The selected weight used will be stored here for Code reference -->
<ActiveWeight>
<ActiveWeightUOM>Pounds</ActiveWeightUOM>
<ActiveWeightSymbol>lb</ActiveWeightSymbol>
</ActiveWeight>
</UOM>
C# code
string xmlFile = Server.MapPath("~/HCConfig/HCUOM.xml");
XmlDocument xmldoc = new XmlDocument();
xmldoc.LoadXml(xmlFile);
XmlNodeList nodeList = xmldoc.GetElementsByTagName("ActiveDimensionSymbol");
string ActiveDimensionSymbol = string.Empty;
foreach (XmlNode node in nodeList)
{
ActiveDimensionSymbol = node.InnerText;
}
How can I achieve this?
You're using the wrong overload, LoadXml doesn't do what you think it does.
Use xmldoc.Load(xmFile); because that method takes an file path as input. LoadXml expects an string with xml in it.
The exception is an indicator of that mistake. What is processed is not XML, and a filepath isn't that.
After this changes the string ActiveDimensionSymbol contains .in if I run this locally.
If you want to use LoadXml you should first read your whole file in a string, for example like so:
xmldoc.LoadXml(File.ReadAllText(xmlFile));
but is really only overhead to call File.ReadAllText if there is an method that accepts a file.
You can use the Descendants() method to get all XElements by certain name, found in the System.Xml.Linq namespace.
XDocument doc = XDocument.Load("XMLFile1.xml");
string[] allActiveWeightUOMs = doc.Descendants("ActiveWeightUOM").Select(o => o.Value).ToArray();
// allActiveWeightUOMs : "Pounds" ...
As can seen here link the method that you are using to load the XML excepts xml by string not xml file. You can use XmlDocument.Load instead of XmlDocument.LoadXml
Try this code its works just fine with this xml
string xmlFile = Server.MapPath("~/HCConfig/HCUOM.xml");
XDocument doc = XDocument.Load(xmlFile );
var nodeList = doc.Descendants("ActiveDimensionSymbol");
string ActiveDimensionSymbol = string.Empty;
foreach (var node in nodeList)
{
ActiveDimensionSymbol = node.Value;
}

Writing data to existing Xml

I am developing a universal windows app on windows 10 with Visual Studio 2015 and have a pretty large Xml structured like this:
<header id = "1">
<title>
some text
</title>
<question>
a question
</question>
<user_input>
<input1>
</input1>
<input2>
</input2>
</user_input>
</header>
<header id = "2">
<title>
some text
</title>
<question>
a question
</question>
<user_input>
<input1>
</input1>
<input2>
</input2>
</user_input>
</header>
...
This is repeating many times. There are parts that should never be changed (e.g. title, question). Now i want to write new elements into "ui", so it can be read again and shows the new content in texbox.
I use a FileStream and XmlDocument and XmlNodeList to read the Xml and show the content on textblocks:
path = "test.xml";
FileStream stream = new Filestream(path, FileMode.Open, FileAcces.Read);
XmlDocument xdoc = new XmlDocument();
xdoc.Load(reader);
XmlNodeList node = xdoc.GetElementsByTagName("header");
textblock1.Text = node[0].Attributes["id"].Value;
textblock2.Text = node[i].ChildNode[1].InnerText;
....
I tried this to write into the Xml:
XDocument xdoc = XDocument.Load(path);
XElement ele = xdoc.Element("header");
ele.Add(new XElement("user_input",
new XElement("input1", newtext)));
xdoc.Save(path); <---- at this point there is an error
"Argument 1: cannot convert from 'string' to 'System.IO.Stream'"
My question is: how can i write the user input (some string) to the place I want it to be? The first input shall be written into header with id = 1 into user_input, the second into header id = "2" and so on. I already tried to load the xml with XDocument and write a new element with XElement, but it work at all.Is there something wrong with my xml? Or is it the function? Thank you in advance.
Firstly, the xml file cannot contain same roots, here you have two headers nodes but don't see a root node. So I add a root node for testing your xml file as follows
<?xml version="1.0" encoding="utf-8"?>
<Topics>
<header id = "1">
...
</header>
</Topics>
Secondly, this error
"Argument 1: cannot convert from 'string' to 'System.IO.Stream'"
xdoc.save(string) is not available in uwp, details you can see the version information of XDocument.Save method.
Thirdly, for this question
how can i write the user input (some string) to the place I want it to be?
we can insert value to special element by xpath or GetElementsByTagName method. In uwp, I recommend you use Windows.Data.Xml.Dom namespace instead of System.xml.Ling.
Here I wrote a demo for insert value to special place . And upload the demo to GitHub, you can download CXml for testing.
Mainly Code
private async void BtnXmlWrite_Click(object sender, RoutedEventArgs e)
{
String input1value = TxtInput.Text;
if (null != input1value && "" != input1value)
{
var value = doc.CreateTextNode(input1value);
//find input1 tag in header where id=1
var xpath = "//header[#id='1']/user_input/input1";
var input1nodes = doc.SelectNodes(xpath);
for (uint index = 0; index < input1nodes.Length; index++)
{
input1nodes.Item(index).AppendChild(value);
}
RichEditBoxSetMsg(ShowXMLResult, doc.GetXml(), true);
}
else
{
await new Windows.UI.Popups.MessageDialog("Please type in content in the box firstly.").ShowAsync();
}
}
More details you can reference XML dom Sample, XML and XPath.

Reading a single node from XML file and using it as a condition

I am simply trying to read a particular node from an XML and use it as a string variable in a condition. This gets me to the XML file and gives me the whole thing.
string url = #"http://agent.mtconnect.org/current";
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(url);
richTextBox1.Text = xmlDoc.InnerXml;
But I need the power state "ON" of "OFF" (XML section below, can view the whole XML online)
<Events><PowerState dataItemId="p2" timestamp="2013-03-11T12:27:30.275747" name="power" sequence="4042868976">ON</PowerState></Events>
I have tried everything I know of. I am just not that familiar with XML files. and the other posts get me nowhere.
HELP PLEASE!
You may try LINQ2XML for that:
string value = (string) (XElement.Load("http://agent.mtconnect.org/current")
.Descendants().FirstOrDefault(d => d.Name.LocalName == "PowerState"))
If you wanted to avoid LINQ, or if it is not working for you you can use straight XML traversal for this:
string url = #"http://agent.mtconnect.org/current";
System.Xml.XmlDocument xmlDoc = new System.Xml.XmlDocument();
xmlDoc.Load(url);
System.Xml.XmlNamespaceManager theNameManager = new System.Xml.XmlNamespaceManager(xmlDoc.NameTable);
theNameManager.AddNamespace("mtS", "urn:mtconnect.org:MTConnectStreams:1.2");
theNameManager.AddNamespace("m", "urn:mtconnect.org:MTConnectStreams:1.2");
theNameManager.AddNamespace("xsi", "http://www.w3.org/2001/XMLSchema-instance");
System.Xml.XmlElement DeviceStreams = (System.Xml.XmlElement)xmlDoc.SelectSingleNode("descendant::mtS:DeviceStream", theNameManager);
System.Xml.XmlNodeList theStreams = DeviceStreams.SelectNodes("descendant::mtS:ComponentStream", theNameManager);
foreach (System.Xml.XmlNode CompStream in theStreams)
{
if (CompStream.Attributes["component"].Value == "Electric")
{
System.Xml.XmlElement EventElement = (System.Xml.XmlElement)CompStream.SelectSingleNode("descendant::mtS:Events", theNameManager);
System.Xml.XmlElement PowerElement = (System.Xml.XmlElement)EventElement.SelectSingleNode("descendant::mtS:PowerState", theNameManager);
Console.Out.WriteLine(PowerElement.InnerText);
Console.In.Read();
}
}
When traversing any document with a default namespace in the root node, I have found it is imperative to have a namespace manager. Without it the document is just un-navigable.
I created this code in a console application. It worked for me. Also I am no guru and I may be making some mistakes here. I am not sure if there is some way to have the default namespace referenced without naming it (mtS). Anyone who knows how to make this cleaner or more efficient please comment.
EDIT:
For one less level of 'clunk' you can change this:
if (CompStream.Attributes["component"].Value == "Electric")
{
Console.Out.WriteLine(((System.Xml.XmlElement)CompStream.SelectSingleNode("descendant::mtS:Events", theNameManager)).InnerText;);
Console.In.Read();
}
because there is only one element in there and its innerText is all you will get.

I am trying to read directory from xml file in c# and have problem

<?xml version="1.0" encoding="UTF-8"?>
<form:Documents xmlns:form="http://www.abbyy.com/FlexiCapture/Schemas/Export/FormData.xsd" xmlns:addData="http://www.abbyy.com/FlexiCapture/Schemas/Export/AdditionalFormData.xsd">
<_Document_Definition_1:_Document_Definition_1 addData:ImagePath="C:\POC\Export\Test.pdf" xmlns:_Document_Definition_1="http://www.abbyy.com/FlexiCapture/Schemas/Export/Document_Definition_1.xsd">
<_Page_1>
<_First_Name>John</_First_Name>
<_Last_Name>Doe</_Last_Name>
</_Page_1>
</_Document_Definition_1:_Document_Definition_1>
</form:Documents>
I have xml containing directory of pdf file which I would need to read.
I can read first name and last name from _Page_1 node but do not know how to read ImagePath.
Here is my code to read from _Page_1
XDocument xDoc = XDocument.Load("Test.xml");
var poc = from p in xDoc.Descendants("_Page_1")
select new
{
FirstName = p.Element("_First_Name").Value,
LastNumber = p.Element("_Last_Name").Value
};
// Execute the query
foreach (var customer in poc)
{
Console.WriteLine(customer.FirstName);
Console.WriteLine(customer.LastName);
}
//Pause the application
Console.ReadLine();
Thank you BrokenGlass, it's working.
I have one more question.
What if I have several iteration of _Document_Definition node, how do I read each iteration.
<?xml version="1.0" encoding="UTF-8"?>
<form:Documents xmlns:form="http://www.abbyy.com/FlexiCapture/Schemas/Export/FormData.xsd" xmlns:addData="http://www.abbyy.com/FlexiCapture/Schemas/Export/AdditionalFormData.xsd">
<_Document_Definition_1:_Document_Definition_1 addData:ImagePath="C:\POC\Export\Test.pdf" xmlns:_Document_Definition_1="http://www.abbyy.com/FlexiCapture/Schemas/Export/Document_Definition_1.xsd">
<_Page_1>
<_First_Name>John</_First_Name>
<_Last_Name>Doe</_Last_Name>
</_Page_1>
</_Document_Definition_1:_Document_Definition_1>
<_Document_Definition_1:_Document_Definition_1 addData:ImagePath="C:\POC\Export\Test2.pdf" xmlns:_Document_Definition_1="http://www.abbyy.com/FlexiCapture/Schemas/Export/Document_Definition_1.xsd">
<_Page_1>
<_First_Name>Jane</_First_Name>
<_Last_Name>Doe</_Last_Name>
</_Page_1>
</_Document_Definition_1:_Document_Definition_1>
</form:Documents>
You are missing the XML namespace references to access those attributes, this works:
XDocument doc = XDocument.Load(#"test.xml");
XNamespace _Document_Definition_1 = "http://www.abbyy.com/FlexiCapture/Schemas/Export/Document_Definition_1.xsd";
XNamespace addData = "http://www.abbyy.com/FlexiCapture/Schemas/Export/AdditionalFormData.xsd";
string impagePath = doc.Descendants(_Document_Definition_1 + "_Document_Definition_1")
.First()
.Attribute(addData + "ImagePath")
.Value;
It looks like Imagepath is an attribute not an element. Hence you are not able to read it. Check for the attributes in the xml file.

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