Inserting "raw" XML string into a XElement - c#

I'm trying to load a node (in string format) into a XElement.
Although this should be easy enough i'm finding some problems:
The node I'm trying to load contains namespace references in some sub-nodes
When I try to use XElement.Load() or Xelement.Parse() I get the expected not defined namespace error
I know the solution is to create a surrounding node with the namespace definitions and then load the whole thing, but I was wondering if there is a more elegant solution that doesn't involve string operations.
Here's my failed attempt :(
I have a collection of namespace attributes:
private readonly List<XAttribute> _namespaces;
This is already populated and contains all the necesary namespaces.
So, to embed my XML string into another node I was doing this:
var temp = new XElement("root", (from ns in _namespaces select ns), MyXMLString);
But as I expected as well, the content of MyXMLString gets escaped and becomes a text node.
The result I get is something like:
<root xmlns:mynamespace="http://mynamespace.com"><mynamespace:node>node text</node></root>
And the result I'm looking for is:
<root xmlns:mynamespace="http://mynamespace.com">
<mynamespace:node>node text</node>
</root>
Is there a neat way to do this?
Thanks in advance

Presumably your XML text is actually well formed (note the namespace qualifier on the closing tag):
var xml = "<mynamespace:node>node text</mynamespace:node>";
In which case you can use this to manually specify the namespaces:
var mngr = new XmlNamespaceManager( new NameTable() );
mngr.AddNamespace( "mynamespace", "urn:ignore" ); // or proper URL
var parserContext = new XmlParserContext(null, mngr, null, XmlSpace.None, null);
Now read and load:
var txtReader = new XmlTextReader( xml, XmlNodeType.Element, parserContext );
var ele = XElement.Load( txtReader );
Works as expected. And you don't need a wrapper 'root' node. Now this can be inserted into any as an XElement anywhere.

Related

Get schemalocation in root Node using XmlDocument using c#

i have to fill up an XML file from a DATA TABLE ,my problem is that i have to get the schemaLocation in the root node ,for this i use the code below ,then i have this result,and i dont know where is p1 coming from
In your resulting XML, p1 is a namespace. The code you have posted (in a screenshot) is defining the namespace "xsi", I'm not sure why your result is generating p1 unless you are renaming xsi somewhere that is not shown.
XmlDocument doc = new XmlDocument();
XmlDeclaration declaire = doc.CreateXmlDeclaration("1.0", "utf-8", null);
XmlElement rootnode = doc.CreateElement("BMECAT");
doc.InsertBefore(declaire, doc.DocumentElement);
doc.AppendChild(rootnode);
rootnode.SetAttribute("version", "2005");
XmlAttribute atr = doc.CreateAttribute("xsi", "schemaLocation", "http://www.w3.org/2001/XMLSchema-instance");
atr.Value = "http://www.adlnet.org/xsd/adlcp.vlp3";
rootnode.SetAttributeNode(atr);
rootnode.Attributes.Append(atr);
In your code:
XmlAttribute atr = doc.CreateAttribute("xsi", "schemaLocation", "http://www.w3.org/2001/XMLSchema-instance");
"xsi" is the name of the namespace it generates, you can control it there. This results in:
<?xml version="1.0" encoding="utf-8"?>
<BMECAT version="2005" xsi:schemaLocation="http://www.adlnet.org/xsd/adlcp.vlp3" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" />
I'm not sure your code matches the result file you provided. When I ran the code, I get "xsi" as expected. If I set "xsi" to null there, it uses a default name, which in my case was d1p1. All instances of "xsi" were replaced with "d1p1". This makes me believe that code might be slightly different from what generated your result. I don't know where "d1p1" came from, it's likely a generated default namespace. This seems like a common default (Remove "d1p1" namespace prefix in DataContractSerializer XML output). In your provided code, if you change "xsi" to "p1" you would get your result.
I might suggest using this method instead:
How to Add schemaLocation attribute to an XML document
Here you would use the accepted answer against your XmlElement rootnode.
XmlElement.SetAttributeValue (localname, prefix, namespace, value)
Please try this code and let me know whether this helped you or not.
Particularly in this code i parse XML file and get the root element:
Then use it to select all attributes named schemaLocation. There is only one, so you can use SelectSingleNode:
The variable
schemaLocationAttribute
Contanins Value attribute through which you can get actual value.
XmlReader xmlReader = XmlReader.Create("MyXML.xml");
XmlDocument xmlDocument = new XmlDocument();
xmlDocument.Load(xmlReader);
XmlElement root = xmlDocument.DocumentElement;
XmlNode schemaLocationAttribute = root.SelectSingleNode("//#*[local-name()='schemaLocation']");
//Single schema value
string schemaValue = schemaLocationAttribute.Value;
//If you have multiple values in your schema
//you have to store it inside of array
string[] multipleShcemavalues = schemaLocationAttribute.Value.Split(null);
//And you have to choose whuickelement you want to use
string chooosendShcema = multipleShcemavalues[1]; //For example

How to Parse Nested XML Nodes in C#

I am very new to C#, but it seems as though this should be pretty straight forward. I am trying to parse an XML string returned from a web feed that looks like this:
<autnresponse xmlns:autn="http://schemas.autonomy.com/aci/">
<action>QUERY</action>
<response>SUCCESS</response>
<responsedata>
<autn:numhits>6</autn:numhits>
<autn:hit>
<autn:reference>http://something.what.com/index.php?title=DPM</autn:reference>
<autn:id>548166</autn:id>
<autn:section>0</autn:section>
<autn:weight>87.44</autn:weight>
<autn:links>Castlmania,POUCH</autn:links>
<autn:database>Postgres</autn:database>
<autn:title>A Pouch and Mail - Castlmania</autn:title>
<autn:content>
<DOCUMENT>
<DRETITLE>Castlmania Pouch and Mail - Castlmania</DRETITLE>
<DRECONTENT>A paragraph of sorts that would contain content</DRECONTENT>
</DOCUMENT>
</autn:content>
</autn:hit>
<autn:hit>...</autn:hit>
<autn:hit>...</autn:hit>
<autn:hit>...</autn:hit>
<autn:hit>...</autn:hit>
</autnresponse>
with no luck.
I am using this code to start:
XmlDocument xmlString = new XmlDocument();
xmlString.LoadXml(xmlUrl);
XmlElement root = xmlString.DocumentElement;
XmlNode GeneralInformationNode =
root.SelectSingleNode("//autnresponse/responsedata/autn:hit");
foreach (XmlNode node in GeneralInformationNode)
{
Console.Write("reference: "+node["autn:reference"]+" Title:"+node["DRETITLE"]+"<br />);
}
And I would like to print the DRETITLE and autn:reference element of within each of the autn:hit elements. Is that even doable with my approach?
I have tried looking and several example on the good old web like this to no avail.
The error that comes back is:
System.Xml.XPath.XpathEception {NameSpace Manager or XsltContext
needed. ...}
Thanks in advance.
UPDATE:
In trying to use XmlNamespaceManager, one has to give it a url to the schema definition like so:
XmlNamespaceManager namespmng = new XmlNamespaceManager (xmlString.NameTable);
namespmng.AddNamespace("autn","http://someURL.com/XMLschema");
The problem seems to be that now the error is gone, but the data is not displaying. I should mention that I am working off of a machine that does not have internet connectivity. The other thing is the schema seems to be unavailable. I am guessing that XmlNamespaceManager would work once able to connect to the internet right?
Using System.Xml.Linq it could be something like this:
var doc = XElement.Load(xmlUrl);
var ns = doc.GetNamespaceOfPrefix("autn");
foreach (var hit in doc.Descendants(ns + "hit"))
{
var reference = hit.Element(ns + "reference").Value;
var dretitle = hit.Descendants("DRETITLE").Single().Value;
WriteLine($"ref: {reference} title: {dretitle}");
}
Firstly, the exception you're getting is because you haven't loaded the namespace using the XmlNamespaceManager for the xml you're parsing. Something like this:
XmlNamespaceManager namespaceManager = new XmlNamespaceManager(xmlString.NameTable);
if (root.Attributes["xmlns:autn"] != null)
{
uri = root.Attributes["xmlns:autn"].Value;
namespaceManager.AddNamespace("autn", uri);
}
Secondly, what you're trying to do is possible. I'd suggest using root.SelectNodes(<your xpath here>) which will return a collection of autn:hit nodes that you can loop through instead of SelectSingleNode which will return one node. Within that you can drill down to the content/DOCUMENT/DRETITLE and pull the text for the DRETITLE node using either XmlNode.Value if you select the text specifically or XmlNode.InnerText on the DRETITLE node.

Cannot parse xml from Yahoo! Fantasy Sports with c#

I did some searching around the web and could not find the cause of my problem so I apologize if that has already been asked in another form I just did not understand.
My problem is that I am trying to parse the XML retrieved from Yahoo! Fantasy Sports but nothing seems to be working.
I have converted the XML I received (using a GET request with my credentials) into a string. Here it is for evaluation.
<?xml version="1.0" encoding="UTF-8" ?>
- <fantasy_content xml:lang="en-US" yahoo:uri="http://fantasysports.yahooapis.com/fantasy/v2/game/223/players" xmlns:yahoo="http://www.yahooapis.com/v1/base.rng" time="5489.1560077667ms" copyright="Data provided by Yahoo! and STATS, LLC" refresh_rate="60" xmlns="http://fantasysports.yahooapis.com/fantasy/v2/base.rng">
- <game>
<game_key>223</game_key>
<game_id>223</game_id>
<name>Football PLUS</name>
<code>pnfl</code>
<type>full</type>
<url>http://football.fantasysports.yahoo.com/f2</url>
<season>2009</season>
- <players count="25">
- <player>
<player_key>223.p.8261</player_key>
<player_id>8261</player_id>
- <name>
<full>Adrian Peterson</full>
<first>Adrian</first>
<last>Peterson</last>
<ascii_first>Adrian</ascii_first>
<ascii_last>Peterson</ascii_last>
</name>
<editorial_player_key>nfl.p.8261</editorial_player_key>
<editorial_team_key>nfl.t.16</editorial_team_key>
<editorial_team_full_name>Minnesota Vikings</editorial_team_full_name>
<editorial_team_abbr>Min</editorial_team_abbr>
- <bye_weeks>
<week>9</week>
</bye_weeks>
<uniform_number>28</uniform_number>
<display_position>RB</display_position>
- <headshot>
<url>http://l.yimg.com/iu/api/res/1.2/7gLeB7TR77HalMeJv.iDVA--/YXBwaWQ9eXZpZGVvO2NoPTg2MDtjcj0xO2N3PTY1OTtkeD0xO2R5PTE7Zmk9dWxjcm9wO2g9NjA7cT0xMDA7dz00Ng--/http://l.yimg.com/j/assets/i/us/sp/v/nfl/players_l/20120913/8261.jpg</url>
<size>small</size>
</headshot>
<image_url>http://l.yimg.com/iu/api/res/1.2/7gLeB7TR77HalMeJv.iDVA--/YXBwaWQ9eXZpZGVvO2NoPTg2MDtjcj0xO2N3PTY1OTtkeD0xO2R5PTE7Zmk9dWxjcm9wO2g9NjA7cT0xMDA7dz00Ng--/http://l.yimg.com/j/assets/i/us/sp/v/nfl/players_l/20120913/8261.jpg</image_url>
<is_undroppable>1</is_undroppable>
<position_type>O</position_type>
- <eligible_positions>
<position>RB</position>
</eligible_positions>
<has_player_notes>1</has_player_notes>
</player>
- <player>
</players>
</game>
</fantasy_content>
The two methods I have tried are these (PLEASE NOTE: "xmlContent" is the string that contains the XML listed above):
1.)
XDocument chicken = XDocument.Parse(xmlContent);
var menus = from menu in chicken.Descendants("name")
select new
{
ID = menu.Element("name").Value,
};
and
2.)
byte[] encodedString = Encoding.UTF8.GetBytes(xmlContent);
MemoryStream ms = new MemoryStream(encodedString);
XmlDocument doc = new XmlDocument();
doc.Load(ms);
foreach (XmlNode row in doc).SelectNodes("//fantasy_content"))
{}
Basically, I get no results enumerated. I have a feeling I am missing some key steps here though. Any help is greatly appreciated. Thank you all.
UPDATE:
As per the awesome suggestions I received, I tried three more things. Since it is not working still, I did not listen very well. :) Actually, that is semi-accurate, please bear with my newbie attempt at working with XML here as I really am thankful for the responses. Here is how I am screwing up the great suggestions, can you offer another tip on what I missed? Thank you all again.
As per Jon Skeet's suggestion (this yields no results for me):
1.) XNamespace ns = "http://fantasysports.yahooapis.com/fantasy/v2/base.rng";
XDocument chicken = XDocument.Parse(xmlContent);
var menus = from menu in chicken.Descendants(ns + "fantasy_content")
select new
{
ID = menu.Element("name").Value,
};
As per the second suggestion (this throws me an error):
2.) var result = XElement.Load(xmlContent).Descendants().Where(x => x.Name.LocalName == "name");
As per the combinations of suggesting I need to identify the namespace and Yahoo! guide at: http://developer.yahoo.com/dotnet/howto-xml_cs.html
3.) xmlContent = oauth.AcquirePublicData(rtUrl, "GET");
byte[] encodedString = Encoding.UTF8.GetBytes(xmlContent);
MemoryStream ms = new MemoryStream(encodedString);
XmlDocument doc = new XmlDocument();
doc.Load(ms);
XmlNamespaceManager ns = new XmlNamespaceManager(doc.NameTable);
ns.AddNamespace("fantasy_content", "http://fantasysports.yahooapis.com/fantasy/v2/base.rng");
XmlNodeList nodes = doc.SelectNodes("/name", ns);
foreach (XmlNode node in nodes)
{
}
This is what's tripping you up:
xmlns="http://fantasysports.yahooapis.com/fantasy/v2/base.rng"
You're asking for elements in the unnamed namespace - but the elements default to the namespace shown above.
It's easy to fix that in LINQ to XML (and feasible but less simple in XmlDocument)
XNamespace ns = "http://fantasysports.yahooapis.com/fantasy/v2/base.rng";
var menus = chicken.Descendants(ns + "name")
...
Note that in your original method you're actually looking for name elements within the name elements - that's not going to work, but the namespace part is probably enough to get you going.
EDIT: It's not clear why you're using an anonymous type at all, but if you really want all the name element values from the document as ID properties in anonymous type instances, just use:
XNamespace ns = "http://fantasysports.yahooapis.com/fantasy/v2/base.rng";
var menus = chicken.Descendants(ns + "name")
.Select(x => new { ID = x.Value });
Note that there's no need to use Descendants(ns + "fantasy_content") as that's just selecting the root element.
Element name consists of two parts: xmlns(namespace) and localname. If xmlns is absent, name is equal to local name. So, you have to create name with namespace or ignore it
You can ignore namespace in your LINQ, just use LocalName
var result = XElement.Load(#"C:\fantasy_content.xml")
.Descendants()
.Where(x => x.Name.LocalName == "name")
.ToList();

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.

Using LINQ to XML to Process XML in Multiple Namespaces

I'm trying to parse results from the YouTube API. I'm getting the results correctly as a string, but am unable to parse it correctly.
I followed suggestions on a previous thread, but am not getting any results.
My sample code is:
string response = youtubeService.GetSearchResults(search.Term, "published", 1, 50);
XDocument xDoc = XDocument.Parse(response, LoadOptions.SetLineInfo);
var list = xDoc.Descendants("entry").ToList();
var entries = from entry in xDoc.Descendants("entry")
select new
{
Id = entry.Element("id").Value,
Categories = entry.Elements("category").Select(c => c.Value)
//Published = entry.Element("published").Value,
//Title = entry.Element("title").Value,
//AuthorName = entry.Element("author").Element("name").Value,
//Thumnail = entry.Element("media:group").Elements("media:thumnail").ToList().ElementAt(0)
};
foreach (var entry in entries)
{
// entry.Id and entry.Categories available here
}
The problem is that entries has a count of 0 even though the XDocument clearly has the valid values.
The value of the response variable (Sample XML) can be seen here: http://snipt.org/lWm
(FYI: The youTube schema is listed here: http://code.google.com/apis/youtube/2.0/developers_guide_protocol_understanding_video_feeds.html)
Can anyone tell me what I'm doing wrong here?
All the data is in the "http://www.w3.org/2005/Atom" namespace; you need to use this throughout:
XNamespace ns = XNamespace.Get("http://www.w3.org/2005/Atom");
...
from entry in xDoc.Descendants(ns + "entry")
select new
{
Id = entry.Element(ns + "id").Value,
Categories = entry.Elements(ns + "category").Select(c => c.Value)
...
};
etc (untested)
When you see prefix:name, it means that name is in the namespace whose prefix has been declared as prefix. If you look at the top of the document, you'll see an xmlns:media=something. The something is the namespace used for anything with the prefix media.
This means you need to create an XNamespace for each of the namespaces you need to reference:
XNamespace media = XNamespace.Get("http://search.yahoo.com/mrss/");
and then use media for the names in that namespace:
media + "group"
The namespaces in this document are:
xmlns="http://www.w3.org/2005/Atom"
xmlns:app="http://www.w3.org/2007/app"
xmlns:media="http://search.yahoo.com/mrss/"
xmlns:openSearch="http://a9.com/-/spec/opensearch/1.1/"
xmlns:gd="http://schemas.google.com/g/2005"
xmlns:gml="http://www.opengis.net/gml"
xmlns:yt="http://gdata.youtube.com/schemas/2007"
xmlns:georss="http://www.georss.org/georss"
You need to set the namespace.
Creating an XName in a Namespace
As with XML, an XName can be in a namespace, or it can be in no namespace.
For C#, the recommended approach for creating an XName in a namespace is to declare the XNamespace object, then use the override of the addition operator.
http://msdn.microsoft.com/en-us/library/system.xml.linq.xname.aspx

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