I was wondering how i can write a specific section of an XDocument to file.
Suppose I load the entire document when my application starts up, and then read settings using application load. When I modify a property of my class, I wish to write JUST THAT PROPERTY (or just that property and its children) back to the file, leaving unchanged any other modification to the XDocument (in memory)
My current code look like the following (note I have some wrappers around the XDocument and XElement classes):
public void SaveRecursiveData()
{
//Load the original file into a new document
XmlConfig tmp = new XmlConfig(_XmlDoc.Filename,false);
//find the node i am interested in
XElement currentElement = tmp.Xmldoc.XPathSelectElement(this.Path);
//Replace it with my IN MEMORY one
currentElement.ReplaceWith(_XmlNode);
//Write the whole temporary document back to the file
tmp.Save();
}
Is this the best approach or is there another way?
You can just do
currentElement.Attribute("toChange").Value = "mynewvalue";
instead of ReplaceWith
Related
Let's say I have one string called data.
How do i put a string's text inside one of it's nodes? How do i choose which one contains the string?
unlike the other questions i saw, my xml will contain many tags. so i dont want so set it to contain one thing, but to add it to the others.
You can use the following to add a text node to your XML file with the data you have:
// Open the XML
XmlDocument doc = new XmlDocument();
doc.LoadXml("<somedata><moredata>sometext</moredata></somedata>");
// Create the new node, set to text and insert the data
XmlNode newElem = doc.CreateNode("text", "yournodename", "");
newElem.InnerText = data;
// Write the new node and append
XmlElement root = doc.DocumentElement;
root.AppendChild(newElem);
If you need something more specific, please provide some more information regarding the node name or the XML Document etc.
UPDATE: As mentioned in the comments, the above code will modify but not save the modifications to the XML. To do so, load the XML document using doc.Load("pathtoyourxml.xml") instead of using doc.LoadXml() and save it to the same path using doc.Save("pathtoyourxml.xml") after doing whatever you are doing with it.
I have a XML file of the following format:
<Alarms>
<Alarm>
<Id>1</Id>
<Severity>Warning</Severity>
<Comments></Comments>
</Alarm>
<Alarm>
<Id>2</Id>
<Severity>Error</Severity>
<Comments>Restart the machine</Comments>
</Alarm>
...
My program has a GUI which gives the user the ability to edit the Comments of an alarm. I am trying to come up with the best solution for the actions to take when a user is done editing and wants to save the changes. The XML file isn't extremely large (it does not warrant a database) but large enough that I do not want to overwrite the entire thing every time a change is made to a single alarm. Is it possible to target only a specific node and edit the Comments attribute without then having to re-write everything?
I'm looking for a XML-specific solution... I want to avoid regular flat-file methods that involve going to a specific line in a file and then editing that line. Perhaps something exists for XML files that I'm not privy to. I'm currently working with a .NET 2 project but will soon be upgrading to 4.5, so any solution works for me.
You can load up the xml in XmlDocument class. Navigate with an XPath query to the Comments node you want to edit and change the value. When you are done, just save the document to the same file name or a different one.
Here is an example using a Console Application.
// The Id of the Alarm to edit
int idToEdit = 2;
// The new comment for the Alarm
string newCommentValue = "Here is a new comment";
XmlDocument doc = new XmlDocument();
doc.LoadXml(xml);
XmlNode commentsElement = doc.SelectSingleNode(String.Format("Alarms/Alarm[Id = '{0}']/Comments", idToEdit));
commentsElement.InnerText = newCommentValue;
doc.Save(Console.Out);
Here is a working fiddle: https://dotnetfiddle.net/eQROet
The title explains most of it. What I am doing probably is not the best solution. I saw many websites saying that you should know the structure of the XML file. But my goal is this.
I want to create a c# function that reads XML information to a list. I want to read the entire file, no matter the structure and keep it in memory.
I already built some code wich reaches every tag in the XML file and it works.
private void Form1_Load(object sender, EventArgs e)
{
XDocument file = XDocument.Load("file.xml");
foreach (XElement element in file.Root.Elements())
{
text += element.Name + Environment.NewLine;
if (element.HasElements)
readElement(element);
}
MessageBox.Show(text);
Application.Exit();
}
private void readElement(XElement element)
{
IEnumerable<XElement> nodes = element.Elements();
foreach (XElement el in nodes)
{
text += el.Name + Environment.NewLine;
if (element.HasElements)
readElement(el);
}
}
So lets say I have this XML file to read:
<?xml version="1.0" encoding="UTF-8"?>
<parent>
<element1>
<element2>
<element3></element3>
</element2>
</element1>
<element4>
<element5></element5>
</element4>
<element6>
<element7>
<element8>
<element9></element9>
</element8>
</element7>
</element6>
</parent>
Like I said, i want the code to be able to work with any XML file, no matter the structure. So my function starts with the root, wich will be an empty list, don't even knowing the type. Since it has children elements, this list will create on fly a list inside it, with the children elements. After that, it will see every child and create a list inside it if it has children elements too.
So at the end, I will have lists inside lists, exactly like the structure of my file. This is where I'm stuck right now, trying to add these list attributes to the root list.
Besides this, I also want to add an attribute with the name 'Value' and type 'object' to store the data inside the tag.
This may be a little confuse to understand and possibly impossible to do, but I just decided to try, since I couldn't find a generic code to read any XML file data on the internet.
Thanks for the help in advance. :)
To begin with I would probably use an XmlReader instead because I think the XDocument.Load will cause problems if the file you are trying to read is a big file.
using (XmlReader reader = XmlReader.Create(#"file.xml"))
{
while (reader.Read())
{
// Process each node (myReader.Value) here
}
}
Hope that helps somewhat at least...
How can I save the content of an xml file to a database( in field which has an XML type)
should I read the content of file with i.e:
FileUpload1.FileContent;
and then send it as a parameter to save in Database? Is it correct?
You have to first save it to the Server hard disk and then get the InnerXML of that to a string variable and then save it to the database.
Assuming you saved the file to some folder in your disk, you can use the below method (using LINQtoXML) to read the content
XElement elm = XElement.Load(Server.MapPath(#"../YourUploadFolder/yourXMl.xml"));
if(elm!=null)
{
var reader = elm.CreateReader();
reader.MoveToContent();
string xmlContent = reader.ReadInnerXml(); xmlContent
// Now save to the database
}
You should use the the XmlReader and XmlTextReader classes to load the XML file into memory. They are defined in the System.XML namespace. You could also use the XDocument class defined in the System.Xml.Linq namespace. For more information please look here :
http://www.c-sharpcorner.com/uploadfile/mahesh/readingxmlfile11142005002137am/readingxmlfile.aspx
http://support.microsoft.com/kb/307548
var reader = new XmlTextReader("C:\\temp\\xmltest.xml");
You then store the XML content as XML in the DB if possible (depending on the DB system you use) or as varchar. Would be better to store them as XML though since you may then assure that its is well-formatted and validated against a certain schema for example !
You can basically fill columns of type XML from an XML literal string, so you can easily just use a normal INSERT statement and fill the XML contents into that field. For this, you have to read the XML file.
You can use the System.Xml.Linq namespace and use XDocument.Load(#"YourXmlFile.xml"); or any standard method to read the XML file as described here - http://support.microsoft.com/kb/307548
I have, outside of my control, an XmlDocument which has a structure like the following:
<parent1>
...minor amount of data...
</parent1>
I have another XmlDocument, also outside of my control, which has the following structure:
<parent2>
..very large amount of data...
</parent2>
I need an XmlDocument in the format:
<parent1>
...minor amount of data...
<parent2>
..very large amount of data...
</parent2>
</parent1>
I don't want to make a copy of parent2. How can I get the structure I need, without copying parent2? I believe this means
oParent1.DocumentElement.AppendChild(oParent1.ImportNode(oParent2.DocumentElement, true));
is out of the question.
Any good solutions out there?
Just remove the DocumentElement from the parent2 XmlDocument, then append the imported parent1 node to the XmlDocument (directly -- NOT to the DocumentElement) and re-append the removed parent2 node to the imported parent1 node:
var p1node = oParent2.ImportNode(oParent1.DocumentElement, true);
var p2node = oParent2.RemoveChild(oParent2.DocumentElement);
oParent2.AppendChild(p1node);
p1node.AppendChild(p2node);