I have following XElement:
<title>
<bold>Foo</bold>
<italic>Bar</italic>
</title>
When I get Value property it returns FooBar without space. How to fix it?
By definition, the Value of the <title> element is the concatenation of all text in this element. By default whitespace between elements and their contents is ignored, so it gives "FooBar". You can specify that you want to preserve whitespace:
var element = XElement.Parse(xml, LoadOptions.PreserveWhitespace);
However it will preserve all whitespace, including the line feeds and indentation. In your XML, there is a line feed and two spaces between "Foo" and "Bar"; how is it supposed to guess that you only want to keep one space?
From the documentation for the Value property of the XElement class:
Gets or sets the concatenated text contents of this element.
Given your example, this behavior is expected. If you want spaces, you will have to provide the logic to do it.
Related
I have occasionally run across XML with some junk characters tossed in between the elements, which appears to be confusing whatever internal XNode/XElement method handles prettifying the Element.
The following...
var badNode = XElement.Parse(#"<b>+
<inner1/>
<inner2/>
</b>"
prints out
<b>+
<inner1 /><inner2 /></b>
while this...
var badNode = XElement.Parse(#"<b>
<inner1/>
<inner2/>
</b>"
gives the expected
<b>
<inner1 />
<inner2 />
</b>
According to the debugger, the junk character gets parsed in as the XElement's "NextNode" property, which then apparently assigns the remaining XML as its "NextNode", causing the single line prettifying.
Is there any way to prevent/ignore this behavior, short of pre-screening the XML for any errant characters in between tag markers?
You getting awkward indentation for badNode because, by adding the non-whitespace + character into the <b> element value, the element now contains mixed content, which is defined by the W3C as follows:
3.2.2 Mixed Content
[Definition: An element type has mixed content when elements of that type may contain character data, optionally interspersed with child elements.]
The presence of mixed content inside an element triggers special formatting rules for XmlWriter (which is used internally by XElement.ToString() to actually write itself to an XML string) that are explained in the documentation remarks for XmlWriterSettings.Indent:
This property only applies to XmlWriter instances that output text content; otherwise, this setting is ignored.
The elements are indented as long as the element does not contain mixed content. Once the WriteString or WriteWhitespace method is called to write out a mixed element content, the XmlWriter stops indenting. The indenting resumes once the mixed content element is closed.
This explains the behavior you are seeing.
As a workaround, parsing your XML with LoadOptions.PreserveWhitespace, which preserves insignificant white space while parsing, might be what you want:
var badNode = XElement.Parse(#"<b>+
<inner1/>
<inner2/>
</b>",
LoadOptions.PreserveWhitespace);
Console.WriteLine(badNode);
Which outputs:
<b>+
<inner1 />
<inner2 />
</b>
Demo fiddle #1 here.
Alternatively, if you are sure that badNode should not have character data, you could strip it manually after parsing:
badNode.Nodes().OfType<XText>().Remove();
Now badNode will no longer contain mixed content and XmlWriter will indent it nicely.
Demo fiddle #2 here.
I am trying to figure out how to write a regex that will strip out the values enclosed in an xml tag. For example,
string xml = "<MyElement1 attribute="bla"><MyElement1>12345</MyElement1></MyElement1>"
I want to know how to do the following:
match on MyElement1 nodes that do not have an attribute
So specifically, using my example I would match <MyElement1>12345</MyElement1> and replace <MyElement1> and </MyElement1> so that my final node looks like this: <MyElement1 attribute="bla">12345</MyElement1>
I've tried: [<][^>]*[>] but this matches on all elements. I'm not sure how to specify specific elements I want to match on.
I have made edits to make the question more focused and clearer as suggested based on the downvotes. I understand that I can use parse and navigate my document tree, but I prefer to use a regex replace of some sort because I want to apply this logic to any number of xml files with different tree structures, elements, and attributes.
Well you really don't need to use regular expressions, you just need to parse your XML using an XML parser.
One of the options you have would be to use the XDocument.Parse( xml ) method and XElement, where the first would be to parse the string, and the second to read it's tag and it's value. An example for reading it would be the following one
string xml = "<MyElement1>12345</MyElement1><MyElement2>abcd</MyElement2><MyElement3>12345</MyElement3><MyElement4>12345</MyElement4>";
// wrap your element in a rootnode (you seem to be missing one in your example)
var document = XDocument.Parse( $"<root>{xml}</root>");
// get the root node and loop over it's children (cast XNode to XElement in the process)
foreach (var node in document.Root.Nodes().OfType<XElement>()) {
// name is tag, value is well, it's value
Console.WriteLine($"{node.Name}: {node.Value}");
}
Note that for the example to parse the document correctly, you must add a rootnode, as xml can have only one rootnode in the document. In my sample, I enclosed the rootnode during the parsing
This sample code uses the System.Xml.Linq namespace, so don't forget to import that one.
One additional comment would be that your supplied XML code had an error in it (MyElemen4 opening tag with MyElement4 closing tag)
I would recommend using a XML Parser but if you want, you can use a simple regex like <([\w]*)>(.*?)<\/[\w]*>, this would return the name of the tag and the value inside.
Output:
Match 1
Full match 0-30 <MyElement1>12345</MyElement1>
Group 1. 1-11 MyElement1
Group 2. 12-17 12345
Match 2
Full match 30-59 <MyElement2>abcd</MyElement2>
Group 1. 31-41 MyElement2
Group 2. 42-46 abcd
Match 3
Full match 59-89 <MyElement3>12345</MyElement3>
Group 1. 60-70 MyElement3
Group 2. 71-76 12345
Match 4
Full match 89-118 <MyElemen4>12345</MyElement4>
Group 1. 90-99 MyElemen4
Group 2. 100-105 12345
Keep in mind it doesn't take in consideration of tag attributes. If you want to fetch a specific tag you can replace [\w] with the tag name you want.
Does anybody know what is the difference between those two below statements :
xdoc.Root.Value;
and
xdoc.Root.ToString();
From my own research, I can see that the first line removes the root node and replaces the '\r\n' to '\n' whereas the second one keeps the content as original. Am I correct ? any documentation to back that up ?
As I want to use the first line but keep the original Windows new lines, is there a way to do that ?
Did you read the documentation?
Value:
A String that contains all of the text content of this element. If there are multiple text nodes, they will be concatenated.
ToString():
Returns the indented XML for this node.
The primary difference is:
ToString() includes the root element tags and the indentation/tabs.
For example:
<Root>
<Child1>1</Child1>
</Root>
Whereas, value doesn't; nor does it maintain the tabs, it just shows the content inside the root tag - it will show you the tags for the children, but not for the root itself:
For example:
<Child1>1</Child1>
XDocument.Parse is retaining unwanted white space when parsing my XML. It appears that my XML is "not indented," which means that white space is retained regardless of whether or not I send in the LoadOptions.PreserveWhitespace flag (http://msdn.microsoft.com/en-us/library/bb551294(v=vs.110).aspx).
This means that when I have XML like the following:
<?xml version="1.0" encoding="UTF-8"?>
<blah:Root xmlns:blah="example.blah.com">
<blah:Element>
value
</blah:Element>
</blah:Root>
and then look at
XDocument xDoc = XDocument.Parse(blahXml);
xElement xEl = xDoc.Root.Element("Element");
string value = xEl.Value;
print value;
it will print "\n value\n" instead of "value".
How do I make XDocument.Parse always ignore white space regardless of whether or not I give it indented or not-indented XML?
White space between elements can be ignored (e.g.
<root>
<foo>foo 1</foo>
<foo>foo 2</foo>
</root>
can be parsed into a root element nodes with two foo child elements node if white space is ignored or into a root element node with five child nodes: text node, foo element node, text node, foo element node, text node), but if an element contains some text data that includes white space then it is considered important. So your only option is indeed to use a method like Trim in the .NET framework or like normalize-space in XPath to have the white space removed when you process the element.
Im reading from a xml and my values seem to come all right except with \n\t\t wrapping them... presumably something to do with spacing and stuff... how do i tell C# to ignore this?
I'm assuming that your XML looks something like this:
<foo>
<bar>
baz
</bar>
</foo>
While that may look pretty for a person, the XML parser is required to preserve all whitespace. Nor is the parser permitted to combine whitespace that appears on either side of an element (so in this case the DOM representation of foo has three children: a Text node containing only whitespace, an Element node for bar, and another Text node containing only whitespace).
Bottom line is that Fredrik's answer is the correct one, but I figured that the rationale behind the behavior was important.
Did you try to call the Trim method on the returned string? That should strip off line feeds, tabs and spaces from the start and end of the string.
I faced this issue in my java program. But not in C#.
This suggestion will help someone.
Below steps I did.
1. Before parsing I read the complete XML as a String.
2. Trim the string
3. replace all "\n" to ""
4. replace all "\t" to ""
Then, I parsed perfectly.