I have an XML file that can be one-line:
<webshop><item></item><item></item></webshop>
or multiline:
<webshop>
<item>
</item>
<item>
</item>
</webshop>
or mixed:
<webshop>
<item></item>
<item></item>
</webshop>
Each tag also has a short variant like <webshop/> and <item/> where the tag is opened and closed in one pair of < > brackets.
each tag can appaer any amount of times, but the <item></item> or <item/> tag will only appaer inside <webshop> ... </webshop>. Also, the entire xml tag hierarchy is much larger then just these two tags (but I kept it simple for this question), and each tag can have attributes.
I'm trying to parse such an xmlfile using an xmlreader in c#, but I always run into a problem.
If I try:
while(reader.ReadToFollowing("webshop"))
{
Console.WriteLine("webshop");
//get attributes of webshop tag and do something...
while(reader.ReadToFollowing("item"))
{
Console.WriteLine("Item");
//get attributes of item tag and do something...
}
}
I never get all the data when the xml is singleline, mixed or the tags close themself (<item/> instead of <item></item>). Most of the time, the reader just stops after one instance of <webshop> or <item>
Is there a robust way to parse this xml, even if the exact lining is not known beforehand? I want to loop over all webshops, and for each webshop loop all over items, and then do something with this data.
Here's a very simple Linq to XML way to read your xml file:
var xml = #"<webshop><item></item><item></item></webshop>";
var reader = XDocument.Parse(xml);
var webshops = from w in reader.Elements("webshop")
select w;
foreach(var shop in webshops)
{
var items = from i in shop.Elements("item")
select i;
//can now grab any attributes of the items
}
Without more details on the attributes in these elements, I can't provide much more detail in an example, but I think this is enough to show you how it can be done.
If you aren't going to do any filtering and just want all of the webshop elements and then their constituent item subelements, you can simplify what I have above like so:
var webshops = reader.Elements("webshop");
foreach(var shop in webshops)
{
var items = shop.Elements("item");
//can now grab any attributes of the items
}
I originally included the more verbose way of structuring the queries in case you wanted to do any filtering or wanted to do something more complex then simply selecting the given elements. This simplified method will produce the same results as my first example.
Please take a look at the answer in this stack overflow discussion.
binding xml elements to model in MVC4
Basically, there are many ways to read xml files in you c# code. It all depend on what you are trying to achieve and how flexible it has to be. I personally prefer to XmlSeriealizer as it translate the xml into c# objects. the only downside is that you have to define classes for the xml to translate into.
Related
I'm using C# in reading an XML file and counting how many "elements" there are in an XML tag, like this for example...
<Languages>English, Deutsche, Francais</Languages>
there are 3 "elements" inside the Languages tag: English, Deutsche, and Francais . I need to know how to count them and return the value of how much elements there are. The contents of the tag have the possibility of changing over time, because the XML file has to expand/accommodate additional languages (whenever needed).
IF this is not possible, please do suggest workarounds for the problem. Thank you.
EDIT: I haven't come up with the code to read the XML file, but I'm also interested in learning how to.
EDIT 2: revisions made to question
string xml = #"<Languages>English, Deutsche, Francais</Languages>";
var doc = XDocument.Parse(xml);
string languages = doc.Elements("Languages").FirstOrDefault().Value;
int count = languages.Split(',').Count();
In response to your edits which indicate that you're not simply trying to pull out comma separated strings from an XML element, then your approach to storing the XML in the first place is incorrect. As another poster commented, it should be:
<Languages>
<Language>English</Language>
<Language>Deutsche</Language>
<Language>Francais</Language>
</Languages>
Then, to get the count of languages:
string xml = #"<Languages>
<Language>English</Language>
<Language>Deutsche</Language>
<Language>Francais</Language>
</Languages>";
var doc = XDocument.Parse(xml);
int count = doc.Element("Languages").Elements().Count();
First, an "ideal" solution: do not put more than one piece of information in a single tag. Rather, put each language in its own tag, like this:
<Languages>
<Language>English</Language>
<Language>Deutsche</Language>
<Language>Francais</Language>
</Languages>
If this is not possible, retrieve the content of the tag with multiple languages, split using allLanguages.Split(',', ' '), and obtain the count by checking the length of the resultant array.
Ok, but just to be clear, an XML Element has a very specific meaning. In fact, the entire codeblock you have is an XML Element.
XElement xElm = new XElement("Languages", "English, Deutsche, Francais");
string[] elements = xElm.Value.Split(",".ToCharArray(), StringSplitOptions.RemoveEmptyEntries);
<?xml version='1.0' encoding='utf-8' standalone='yes'?>
<stock-items>
<stock-item>
<name>Loader 34</name>
<sku>45GH6</sku>
<vendor>HITINANY</vendor>
<useage>Lifter 45 models B to C</useage>
<typeid>01</typeid>
<version>01</version>
<reference>33</reference>
<comments>EOL item. No Re-order</comments>
<traits>
<header>56765</header>
<site>H4</site>
<site>A6</site>
<site>V1</site>
</traits>
<type-validators>
<actions>
<endurance-tester>bake/shake</endurance-tester>
</actions>
<rules>
<results-file>Test-Results.txt</results-file>
<file-must-contain file-name="Test-Results.xml">
<search>
<term>[<![CDATA[<"TEST TYPES 23 & 49 PASSED"/>]]></term>
<search-type>exactMatch</search-type>
</search>
</file-must-contain>
</rules>
</type-validators>
</stock-item>
</stock-items>
Im trying to get the rules fragment from the xml above into a string so it can be added to a database. Currently the search element and its contents are added twice. I know why this is happing but cant figure out how to prevent it.
Heres my code
var Rules = from rules in Type.Descendants("rules")
select rules.Descendants();
StringBuilder RulesString = new StringBuilder();
foreach (var rule in Rules)
{
foreach (var item in rule)
{
RulesString.AppendLine(item.ToString());
}
}
Console.WriteLine(RulesString);
Finally any elements in rules are optional and some of these elements may or may not contain other child elements up to 4 or 5 levels deep. TIA
UPDATE:
To try and make it clearer what im trying to achieve.
From the xml above I should end up with a string containing everthing in the rules element, exactly like this:
<results-file>Test-Results.txt</results-file>
<file-must-contain file-name="Test-Results.xml">
<search>
<term>[<![CDATA[<"TEST TYPES 23 & 49 PASSED"/>]]></term>
<search-type>exactMatch</search-type>
</search>
</file-must-contain>
Objective is to extract the entire contents of the rules element as is while taking account that the rules element may or may not contains child elements several levels deep
If you just want the entirety of the rules element as a string (rather than caring about its contents as xml), you don't need to dig into its contents, you just need to get the element as an XNode and then call ToString() on it :
The following example uses this method to retrieve indented XML.
XElement xmlTree = new XElement("Root",
new XElement("Child1", 1)
);
Console.WriteLine(xmlTree);
This example produces the following output:
<Root>
<Child1>1</Child1>
</Root>
if you want to prevent duplicates than you will need to use Distinct() or GroupBy() after parsing the xml and before building the string.
I'm still not fully understanding exactly what the output should be, so I can't provide a clear solution on what exactly to use, or how, in terms of locating duplicates. If you can refine the original post that would help.
we need the structure of the xml as it would appear in your scenario. nesting and all.
we need an example of the final string.
saving it to a db doesn't really matter for this post so you only need to briefly mention that once, if at all.
Programming in C# I got an Xml.XpathNodeList object "ResultsPartRel.nodeList". Debugging it with Visual Studio I can read "Results View ; Expanding the Results View will enumerate the IEnumerable"
Questions:
1.- Which is the best way to read those nodes?
2.- I program the next code but I dont get the expected results. I get the same result twice. (ResultsPartRel.nodeList contains 2 nodes)
List<string> childrenName = new List<string>();
foreach (XmlElement node in ResultsPartRel.nodeList)
{
string nameChildren = node.SelectSingleNode("//related_id/Item/keyed_name").InnerText;
childrenName.Add(nameChildren);
}
Thank you in advance.
EDIT
<related_id>
<Item>
<classification>Component</classification>
<id></id>
<keyed_name>glass</keyed_name> <!-- I want to get this InnerText -->
</Item>
</related_id>
<source_id>968C45A47942454DA9B34245A9F72A8C</source_id>
<itemtype>5E9C5A12CC58413A8670CF4003C57848</itemtype>
Well we really need to see the XML sample and a verbal explanation of which data you want to extract. Currently you do a node.SelectSingleNode(...) so that looks as if you want to select a path relative to node but then you use an absolute path starting with //, that is why you get the same result twice.
So you want node.SelectSingleNode(".//related_id/Item/keyed_name") or perhaps even node.SelectSingleNode("related_id/Item/keyed_name"), depending on the XML you have.
You can get the first element. (With the "//" means search for all following tags, so you will probably get more results).When you want the first element write "//related_id/Item/keyed_name*1*".
Or you can write the exact path.(this is the safest way) To make it easy for yourself there is a Firefox extension xPath Checker load the document in firefox than right click the element and show Xpath. Then you get a exact path.
I have an XML file as follows:
I uploaded the XML file : http://dl.dropbox.com/u/10773282/2011/result.xml . It's a machine generated XML, so you might need some XML viewer/editor.
I use this C# code to get the elements in CoverageDSPriv/Module/*.
using System;
using System.Xml;
using System.Xml.Linq;
namespace HIR {
class Dummy {
static void Main(String[] argv) {
XDocument doc = XDocument.Load("result.xml");
var coveragePriv = doc.Descendants("CoverageDSPriv"); //.First();
var cons = coveragePriv.Elements("Module");
foreach (var con in cons)
{
var id = con.Value;
Console.WriteLine(id);
}
}
}
}
Running the code, I get this result.
hello.exe6144008016161810hello.exehello.exehello.exe81061hello.exehello.exe!17main_main40030170170010180180011190190012200200013hello.exe!107testfunctiontestfunction(int)40131505001460600158080216120120017140140018AA
I expect to get
hello.exe
61440
...
However, I get just one line of long string.
Q1 : What might be wrong?
Q2 : How to get the # of elements in cons? I tried cons.Count, but it doesn't work.
Q3 : If I need to get nested value of <CoverageDSPriv><Module><ModuleNmae> I use this code :
var coveragePriv = doc.Descendants("CoverageDSPriv"); //.First();
var cons = coveragePriv.Elements("Module").Elements("ModuleName");
I can live with this, but if the elements are deeply nested, I might be wanting to have direct way to get the elements. Are there any other ways to do that?
ADDED
var cons = coveragePriv.Elements("Module").Elements();
solves this issue, but for the NamespaceTable, it again prints out all the elements in one line.
hello.exe
61440
0
8
0
1
6
1
61810hello.exehello.exehello.exe81061hello.exehello.exe!17main_main40030170170010180180011190190012200200013hello.exe!107testfunctiontestfunction(int)40131505001460600158080216120120017140140018
Or, Linq to XML can be a better solution, as this post.
It looks to me like you only have one element named Module -- so .Value is simply returning you the InnerText of that entire element. Were you intending this instead?
coveragePriv.Element("Module").Elements();
This would return all the child elements of the Module element, which seems to be what your'e after.
Update:
<NamespaceTable> is a child of <Module> but you appear to want to handle it similarly to <Module> in that you want to write out each child element. Thus, one brute-force approach would be to add another loop for <NamespaceTable>:
foreach (var con in cons)
{
if (con.Name == "NamespaceTable")
{
foreach (var nsElement in con.Elements())
{
var nsId = nsElement.Value;
Console.WriteLine(nsId);
}
}
else
{
var id = con.Value;
Console.WriteLine(id);
}
}
Alternatively, perhaps you'd rather just denormalize them altogether via .Descendents():
var cons = coveragePriv.Element("Module").Descendents();
foreach (var con in cons)
{
var id = con.Value;
Console.WriteLine(id);
}
XMLElement.Value has unexpected results. In XML using .net you are really in charge of manually traversing the xml tree. If the element is text then value may return what you want but if its another element then not so much.
I have done a lot of xml parsing and I find there are way better ways to handle XML depending on what you are doing with the data.
1) You can look into XSLT transforms if you plan on outputting this data as text, more xml, or html. This is a great way to convert the data to some other readable format. We use this when we want to display our metadata on our website in html.
2) Look into XML Serialization. C# makes this very easy and it is amazing to use because then you can work with a regular C# object when consuming the data. MS even has tools to create the serlization class from the XML. I usually start with that, clean it up and add my own tweaks to make it work as I wish. The best way is to deserialize the object to XML and see if that matches what you have.
3) Try Linq to XML. It will allow you to query the XML as if it were a database. It is a little slower generally but unless you need absolute performance it works very well for minimizing your work.
Say I need to find a particular node in an XML file, using C#.
<node attribute="my-target-attribute">
"my-target-attribute" is a variable input at runtime.
The node is in no particular place in the XML file, I basically just need to scan the entire XML hierarchy until I find a node with the matching attribute.
Is there any way I can pre-process the XML so finding the node will be faster? I need to keep the original XML structure in place. The XML file could potentially have 10,000 nodes.
You can certainly preprocess the XML to make lookups faster:
Dictionary<string, XmlElement> elementMap = new Dictionary<string, XmlElement>();
AddElementToMap(doc.DocumentElement, elementMap);
...
private void AddElementToMap(XmlElement elm, Dictionary<string, XmlElement> elementMap)
{
elementMap[elm.GetAttribute("attribute")] = elm;
foreach (XmlElement child in elm.SelectNodes("node"))
{
AddElementToMap(child, elementMap);
}
}
Once you've done this, a lookup is simple:
XmlElement elm = elementMap[value];
That code assumes that every element in your document is named "node", that every one has an attribute named "attribute", and that all of the attribute values are unique. The code's more complicated if any of those conditions are untrue, but not exceptionally so.
You could use xslt to transform the xml so that the node is in a known depth. Then when you select with XPath, you can select accordingly without using the // operator.
With VTD-XML (http://vtd-xml.sf.net) you can index the XML document into VTD+XML,
which eliminate the overhead of parsing
http://www.codeproject.com/KB/XML/VTD-XML-indexing.aspx
similar to another answer, you can use xpath similar like selectNodes("//[#attribute='my-target-attribute']"). // will search nodes in all level depths.