I have a WCF service that needs to return a string of XML. But it seems like the writer only wants to build up a file, not a string. I tried:
string nextXMLstring = "";
using (XmlWriter writer = XmlWriter.Create(nextXMLstring))
This generates an error saying nextXMLstring doesnt have a file path. It wants something like:
using (XmlWriter writer = XmlWriter.Create("nextXMLstring.xml"))
How can I build up my XML and then return it as a string??
Thanks!!
You need to create a StringWriter, and pass that to the XmlWriter.
The string overload of the XmlWriter.Create is for a filename.
E.g.
using (var sw = new StringWriter()) {
using (var xw = XmlWriter.Create(sw)) {
// Build Xml with xw.
}
return sw.ToString();
}
As Richard said, StringWriter is the way forward. There's one snag, however: by default, StringWriter will advertise itself as being in UTF-16. Usually XML is in UTF-8. You can fix this by subclassing StringWriter;
public class Utf8StringWriter : StringWriter
{
public override Encoding Encoding
{
get { return Encoding.UTF8; }
}
}
This will affect the declaration written by XmlWriter. Of course, if you then write the string out elsewhere in binary form, make sure you use an encoding which matches whichever encoding you fix for the StringWriter. (The above code always assumes UTF-8; it's trivial to make a more general version which accepts an encoding in the constructor.)
You'd then use:
using (TextWriter writer = new Utf8StringWriter())
{
using (XmlWriter xmlWriter = XmlWriter.Create(writer))
{
...
}
return writer.ToString();
}
I know this is old and answered, but here is another way to do it. Particularly if you don't want the UTF8 BOM at the start of your string and you want the text indented:
using (var ms = new MemoryStream())
using (var x = new XmlTextWriter(ms, new UTF8Encoding(false))
{ Formatting = Formatting.Indented })
{
// ...
return Encoding.UTF8.GetString(ms.ToArray());
}
Use StringBuilder:
var sb = new StringBuilder();
using (XmlWriter xmlWriter = XmlWriter.Create(sb))
{
...
}
return sb.ToString();
Guys don't forget to call xmlWriter.Close() and xmlWriter.Dispose() or else your string won't finish creating. It will just be an empty string
Well I think the simplest and fastest solution here would be just to:
StringBuilder sb = new StringBuilder();
using (var writer = XmlWriter.Create(sb, settings))
{
... // Whatever code you have/need :)
sb = sb.Replace("encoding=\"utf-16\"", "encoding=\"utf-8\""); //Or whatever uft you want/use.
//Before you finally save it:
File.WriteAllText("path\\dataName.xml", sb.ToString());
}
Related
i have this simple code:
var xel=new XElement("myElement");
xel.Value="\r"; // assign carriage return
xel.Save(#"file.xml",,SaveOptions.DisableFormatting)
If i open the file with notepad++ and i show all chars, i see that the element value is saved as CR+LF.
Then, i'm not able to read the file again.
Anyone can help me?
Thanks!
Edit:
i found follow solution, but i' m not sure that it is the best one.
var xel = new XElement("myElement");
xel.Value = "\r";
XmlWriterSettings settings = new XmlWriterSettings();
settings.NewLineHandling=NewLineHandling.None;
settings.OmitXmlDeclaration = true;
System.Text.StringBuilder result = new System.Text.StringBuilder();
using (XmlWriter writer = XmlWriter.Create(result, settings)) {
xel.WriteTo(writer);
}
var text = result.ToString(); // expected output
this should work (changed SaveOptions ) refer this
var xel=new XElement("myElement");
xel.Value="\r"; // assign carriage return
xel.Save(#"C:\file.xml",SaveOptions.None);
I am trying to write an XML response for my web service however I can't figure out how to make the declaration appear in the response.
My code is like so :
StringBuilder sBuilder = new StringBuilder();
using (XmlWriter writer = XmlWriter.Create(sBuilder))
{
writer.WriteStartDocument();
writer.WriteStartElement("ReportResponse");
Response.WriteXml(writer);
writer.WriteEndElement();
writer.WriteEndDocument();
}
var response = XElement.Parse(sBuilder.ToString());
return response;
Response is just a POCO for storing response data.
I am aware that the Save method includes the declaration and the ToString() method does not. I need to write my declaration back with ToString().
I really just want to return custom XML from my REST Service without casting my string 100 times to return valid XML. Is this even possible or am just spinning my wheels ?
If you want to include xml declaration, you can do it this way:
XDocument xdoc = XDocument.Parse(xmlString);
StringBuilder builder = new StringBuilder();
using (TextWriter writer = new StringWriter(builder))
{
xdoc.Save(writer);
}
Console.WriteLine(builder);
Update:
I've noticed, that StringWriter spoils encoding. So one more option is to do so:
string docWithDeclaration = xdoc.Declaration + xdoc.ToString();
my code is outputting some weird character at the very start of my XSLT output XML and neither Visual Studio 2008 or notepad show it up. But it's definitely there because VS lets me delete it and will then auto-format the XML properly. How do I stop this? Here's my code:
// create the readers for the xml and xsl
XmlReader reader = XmlReader.Create(
new StringReader(LoadFileAsString(MapPath(xslPath)))
);
XmlReader input = XmlReader.Create(
new StringReader(LoadFileAsString(MapPath(xmlPath)))
);
// create the xsl transformer
XslCompiledTransform t = new XslCompiledTransform(true);
t.Load(reader);
// create the writer which will output the transformed xml
StringBuilder sb = new StringBuilder();
//XmlWriterSettings tt = new XmlWriterSettings();
//tt.Encoding = Encoding.Unicode;
XmlWriter results = XmlWriter.Create(new StringWriter(sb));//, tt);
// write the transformed xml out to a stringbuilder
t.Transform(input, null, results);
// return the transformed xml
WriteStringAsFile(MapPath(outputXmlPath), sb.ToString());
public static string LoadFileAsString(string fullpathtofile)
{
string a = null;
using (var sr = new StreamReader(fullpathtofile))
a = sr.ReadToEnd();
return a;
}
public static void WriteStringAsFile(string fullpathtofile, string content)
{
File.WriteAllText(fullpathtofile, content.Trim(), Encoding.Unicode);
}
That thing at the beginning of your XML output document is most likely a byte-order-mark or BOM, which indicates whether the bytes in your Unicode output are in big-endian or little-endian order.
This BOM might be useful for consumers of your XML document; however, in some cases it might lead to problems and then it is better not to create it.
You can specify whether a BOM is created using the Encoding specified via XmlWriterSettings:
XmlWriterSettings xmlWriterSettings = new XmlWriterSettings();
xmlWriterSettings.Encoding = new UTF8Encoding(false);
The code above will create your document using UTF8 encoding. This is most likely what you want to have unless your consuming system explicitly asks for UTF16/Unicode encoding or you are dealing with Asian character.
To create a UTF16/Unicode encoded document use UnicodeEncoding with the second parameter set to false:
XmlWriterSettings xmlWriterSettings = new XmlWriterSettings();
xmlWriterSettings.Encoding = new UnicodeEncoding(false, false);
I have an XmlTextWriter writing to a file and an XmlWriter using that text writer. This text writer is set to output tab-indented XML:
XmlTextWriter xtw = new XmlTextWriter("foo.xml", Encoding.UTF8);
xtw.Formatting = Formatting.Indented;
xtw.IndentChar = '\t';
xtw.Indentation = 1;
XmlWriter xw = XmlWriter.Create(xtw);
Changed per Jeff's MSDN link:
XmlWriterSettings set = new XmlWriterSettings();
set.Indent = true;
set.IndentChars = "\t";
set.Encoding = Encoding.UTF8;
xw = XmlWriter.Create(f, set);
This does not change the end result.
Now I'm an arbitrary depth in my XmlWriter and I'm getting a string of XML from elsewhere (that I cannot control) that is a single-line, non-indented XML. If I call xw.WriteRaw() then that string is injected verbatim and does not follow my indentation I want.
...
string xml = ExternalMethod();
xw.WriteRaw(xml);
...
Essentially, I want a WriteRaw that will parse the XML string and go through all the WriteStartElement, etc. so that it gets reformatted per the XmlTextWriter's settings.
My preference is a way to do this with the setup I already have and to do this without having to reload the final XML just to reformat it. I'd also prefer not to parse the XML string with the likes of XmlReader and then mimic what it finds into my XmlWriter (very very manual process).
At the end of this I'd rather have a simple solution than one that follows my preferences. (Best solution, naturally, would be simple and follows my preferences.)
How about using a XmlReader to read the xml as xml nodes?
string xml = ExternalMethod();
XmlReader reader = XmlReader.Create(new StringReader(xml));
xw.WriteNode(reader, true);
You shouldn't use XmlTextWriter, as indicated in MSDN where it states:
In the .NET Framework version 2.0
release, the recommended practice is
to create XmlWriter instances using
the XmlWriter.Create method and the
XmlWriterSettings class. This allows
you to take full advantage of all the
new features introduced in this
release. For more information, see
Creating XML Writers.
Instead, you should use XmlWriter.Create to get your writer. You can then use the XmlWriterSettings class to specify things like indentation.
XmlWriterSettings settings = new XmlWriterSettings();
settings.Indent = true;
settings.IndentChars = "\t";
Update
I think you can just use WriteNode. You take your xml string and load it into an XDocument or XmlReader and then use the node from that to write it into your XmlWriter.
This is the best I've got so far. A very manual process that only supports what is written. My string XML is nothing more than tags, attributes, and text data. If it supported namespaces, CDATA, etc. then this would have to grow accordingly.
Very manual, very messy and very likely prone to bugs but it does accomplish my preferences.
private static void PipeXMLIntoWriter(XmlWriter xw, string xml)
{
byte[] dat = new System.Text.UTF8Encoding().GetBytes(xml);
MemoryStream m = new MemoryStream();
m.Write(dat, 0, dat.Length);
m.Seek(0, SeekOrigin.Begin);
XmlReader r = XmlReader.Create(m);
while (r.Read())
{
switch (r.NodeType)
{
case XmlNodeType.Element:
xw.WriteStartElement(r.Name);
if (r.HasAttributes)
{
for (int i = 0; i < r.AttributeCount; i++)
{
r.MoveToAttribute(i);
xw.WriteAttributeString(r.Name, r.Value);
}
}
if (r.IsEmptyElement)
{
xw.WriteEndElement();
}
break;
case XmlNodeType.EndElement:
xw.WriteEndElement();
break;
case XmlNodeType.Text:
xw.WriteString(r.Value);
break;
default:
throw new Exception("Unrecognized node type: " + r.NodeType);
}
}
}
composing the answers above I have found this works:
private static string FormatXML(string unformattedXml) {
// first read the xml ignoring whitespace
XmlReaderSettings readeroptions= new XmlReaderSettings {IgnoreWhitespace = true};
XmlReader reader = XmlReader.Create(new StringReader(unformattedXml),readeroptions);
// then write it out with indentation
StringBuilder sb = new StringBuilder();
XmlWriterSettings xmlSettingsWithIndentation = new XmlWriterSettings { Indent = true};
using (XmlWriter writer = XmlWriter.Create(sb, xmlSettingsWithIndentation)) {
writer.WriteNode(reader, true);
}
return sb.ToString();
}
How about:
string xml = ExternalMethod();
var xd = XDocument.Parse(xml);
xd.WriteTo(xw);
I was looking for an answer to this issue but in VB.net.
Thanks to Colin Burnett, I solved it. I made two corrections: first, the XmlReader has to ignore white spaces (settings.IgnoreWhiteSpaces); second, the reader has to be back into the element after it reads attributes. Below you can see how the code looks like.
Also I tried the solution of GreyCloud, but in the generated XML there were some annoying empties attributes (xlmns).
Private Sub PipeXMLIntoWriter(xw As XmlWriter, xml As String)
Dim dat As Byte() = New System.Text.UTF8Encoding().GetBytes(xml)
Dim m As New MemoryStream()
m.Write(dat, 0, dat.Length)
m.Seek(0, SeekOrigin.Begin)
Dim settings As New XmlReaderSettings
settings.IgnoreWhitespace = True
settings.IgnoreComments = True
Dim r As XmlReader = XmlReader.Create(m, settings)
While r.Read()
Select Case r.NodeType
Case XmlNodeType.Element
xw.WriteStartElement(r.Name)
If r.HasAttributes Then
For i As Integer = 0 To r.AttributeCount - 1
r.MoveToAttribute(i)
xw.WriteAttributeString(r.Name, r.Value)
Next
r.MoveToElement()
End If
If r.IsEmptyElement Then
xw.WriteEndElement()
End If
Exit Select
Case XmlNodeType.EndElement
xw.WriteEndElement()
Exit Select
Case XmlNodeType.Text
xw.WriteString(r.Value)
Exit Select
Case Else
Throw New Exception("Unrecognized node type: " + r.NodeType)
End Select
End While
End Sub
Is there any way to take an xml string in .net and make it easyer to read?
what i mean is can i convert this:
<element1><element2>some data</element2></element1>
to this:
<element1>
<element2>
some data
</element2>
</element1>
is there any built in class for this? as sql server 2005 seems to remove all formatting on xml to save space or some thing...
If you're using .NET 3.5, you can load it as an XDocument and then just call ToString() which will indent it appropriately. For example:
using System;
using System.Xml.Linq;
public class Test
{
static void Main()
{
string xml = "<element1><element2>some data</element2></element1>";
XDocument doc = XDocument.Parse(xml);
xml = doc.ToString();
Console.WriteLine(xml);
}
}
Result:
<element1>
<element2>some data</element2>
</element1>
If you're writing it to a file or other stream, then XDocument.Save will (by default) indent it too.
(I believe XElement has all the same features, if you don't really need an XDocument.)
How do you save / write the XML back to a file ?
You can create an XmlWriter and pass it an XmlWriterSettings instance, where you set the Indent property to true:
XmlWriterSettings settings = new XmlWriterSettings();
settings.Indent = true;
XmlWriter writer = XmlWriter.Create (outputStream, settings);
You can load the string into an XDocument object and save it to a string again:
XDocument doc = XDocument.Load(new StringReader(xmlString));
StringWriter writer = new StringWriter();
doc.Save(writer);
string readable = writer.ToString();
That will give you the xml formatted this way:
<?xml version="1.0" encoding="utf-16"?>
<element1>
<element2>some data</element2>
</element1>
Have a look at
XmlWriterSettings
http://msdn.microsoft.com/en-us/library/system.xml.xmlwritersettings.aspx
you can define Indent and IndentChars
First of all, you have tagged C# and VB.NET both. So my answer will be for both of them.
You can define function which get XML string as a parameter in type of String.
Let's say;
You created a function as :
[VB]
Private Function PrettyXML(XMLString As String) As String
Dim sw As New StringWriter()
Dim xw As New XMLWriter(sw)
xw.Formatiing = Formatting.Indented
xw.Indentation = 4
Dim doc As New XMLDocument
doc.LoadXML(XMLString)
doc.Save(xw)
Return sw.ToString()
End Function
Then you can simpyl call this function as:
Dim myXML As String = "<element1><element2>some data</element2></element1>"
Dim myPrettyXML As String
myPrettyXML = PrettyXML(myPrettyXML)
[C#]
Private String PrettyXML(string XMLString)
{
StringWriter sw = new StringWriter();
XMLTextWriter xw = new XmlTextWriter(sw);
xw.Formatiing = Formatting.Indented;
xw.Indentation = 4;
XmlDocument doc = new XmlDocument();
doc.Save(xm);
return sw.ToString();
}
Then you can simply call this function as:
string myXML = "<element1><element2>some data</element2></element1>";
string myPrettyXML = "";
myPrettyXML = PrettyXML(myPrettyXML);
NOTE: I have not tried C# version, but it should work.
Hope this helps..