expression builder for XML - c#

In my program I get passed some XML. If values in this XML fulfil a user defined criteria I store the xml otherwise it gets discarded. The problem I have is that I need to be able to allow the user to define the criteria (also combining multiple element with “OR” and “AND”) and then applying this when I get the XML. This is a C# application, can anyone recommend a library, tool or help in which way I should go about resolving this problem? Shown below is the XML that I will receive. The user may only want to store this if <unit> =1 AND (the first part of <data> = Z OR <data> has ABC after the second coma).
<interface>
<mac>12345</mac>
<device>DeviceTypeA</device>
<id>TestUnit</id>
<data>
<unit>1</unit>
<transaction>
<event>0</event>
<data>Z,0,ABC,1234</data>
<time>2010-06-29T11:33:44.0000000Z</time>
</transaction >
</data>
</interface>

Do your users get to see the XML at all? If so, you could simply allow the user to input an XPath expression, such as
/interface/data/unit=1
or
substring-before(',',/interface/data/transaction/data)='Z'
then simply do
if (xml.SelectNodes(xPathExpression) == null) /*discard*/
IMHO anyone who works with XML should be encouraged to learn XPath; you could provide a few simple examples next to the input to help.
If your users don't see the XML, you're probably better off having a few predefined conditions that the user can select from and then supply a value, otherwise you're going to have to create a whole expression parser, which is probably overkill for a task like this.

Related

How i Can Read XML Element and Attribute Values from Below Example

Below Example How can Get "Airtel" and "145" Values, because my Client Has given this type XML Response
So How Can I Get both Values
<item item="Campaign name" type="string">Airtel</item>
<item item="Daily Limit" type="number">145</item>
As per the comment, we would need to see the full XML to give you a more complete answer. But you have 3 real options :
XMLReader. Probably not what you want as it's forward only and involves a lot of manual parsing.
XMLDocument. Not a bad option if you only want limited amount of notes and want their values and don't want to deserialize the entire XML doc.
XMLSerializer. Good if you want to deserialize the entire object straight from XML to class without you having to do a heck of a lot.
If you edit your question to include the full XML doc, then I can give you a more complete answer or you can read about your options for parsing XML here : https://dotnetcoretutorials.com/2020/04/23/how-to-parse-xml-in-net-core/

How to parse an xml that has non-xml data in it

I am working with some xml in C# and am having some issues parsing an xml file due to the format it is in. It has non xml data in the file and I have no control over the format of this file. The file is "test.xml"(see below). I am only concerned with the xml portion of the data, but am unsure the best way to go about accessing it. Any thoughts or recommendations would be greatly appreciated.
Test data -1
Smith, 2234
##*j
Random--
#<?xml version="1.0" encoding="utf-16"?>
<ConfigMessage xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://www.Test.com/schemas/Test.test.Config">
<Config>
<Version>10</Version>
<Build>00520</Build>
<EnableV>false</EnableV>
<BuildL>22</BuildL>
<BuildP>\\testpath\test</BuildP>
</Config>
</ConfigMessage>
#
Put the whole file into a string that contains anything within the first '<' and the last '>' characters detected on the file. Then you can treat it as normal XML from there. If there's random non-XML elements throughout it though you will need to add additional logic to detect starting/stopping XML "blocks".
I can suggest you such solution: open your pseudo-xml like simple text-file, read whole text, after that, with using regex you ought to take xml document (part of primordial document that is able to be converted to XML [|startTag|any symbols|/endTag|]), put it into XDocument (in memory) and now parse it like XML-file.

Get all attributes with the same name

I'm using XDocument and I need to parse my XML file to retrieve all attribute with the same name event if its node's name is different from the other.
For example, for this XML :
<document>
<person name='jame'/>
<animals>
<dog name='robert'/>
</animals>
</document>
I want to retrieve all attributes named 'name'.
Can I do that with one request XPath or do I need to parse every node to find thos attributes ?
Thanks for your help !
The XPath expression
//#name
will select all attributes called name, regardless of where they appear.
By the way, 'parsing' is something that happens to the XML document before XPath ever enters the picture. So when you say "do I need to parse every node", I think this isn't really what you mean. The entire document is typically already parsed before you run an XPath query. However, I'm not sure what you do mean instead of 'parse'. Probably something like "do I need to visit every element" to find those attributes? In which case the answer is no, unless in some vague implementation-dependent sense that doesn't make any difference to you.

How would I parse an entire XML file that is possibly malformed?

So far, what I'm doing is:
try
{
XmlDocument xmldoc = loadXml(orderFilePath);
}
catch (XmlException exception)
{
//... blah blah - there was an error, let the user know
}
But I would really like to be able to attempt to parse the file anyway. When I say "malformed" I don't necessarily mean that there will be an unclosed tag or element, but that there might be something like one of the following included in an element's value: '<', '>', '&'
I've seen mentioned around that I would probably have to use XmlReader - but would that still throw an exception on that element, or allow me to fix the problem in some way?
I know fixing the XML at the source is the best solution, but I do not control where the XML is coming from.
Thanks!
EDIT:
Super simple example of the XML:
<Order>
<Customer_ID>555-555-5555</Customer_ID>
<ShipToAddress>
<Customer_Name>Some Guy</Customer_Name>
<Street>123 Fake Dr.</Street>
<Street2></Street2>
<City>West Palm Beach</City>
<State>FL</State>
<ZipCode>33417</ZipCode>
<Country>United States</Country>
</ShipToAddress>
<BillToAddress>
<Customer_Name>Some Guy</Customer_Name>
<Street>123 Fake Dr.</Street>
<Street2></Street2>
<City>West Palm Beach</City>
<State>FL</State>
<ZipCode>33417</ZipCode>
<Country>United States</Country>
</BillToAddress>
<items>
<item>
<Product_ID>25101</Product_ID>
<Product_Name></Product_Name>
<Quantity>1</Quantity>
<USPrice>26.95000</USPrice>
</item>
</items>
<!-- bad stuff here -->
<How_did_you_hear_about_us>Coffee & Tea magazine</How_did_you_hear_about_us>
<!-- bad stuff here -->
</Order>
The thing is - I don't necessarily know if it will always be in the same place.
One approach could be to validate a few things before parsing it. You could use a regex to validate the XML tags, but perhaps more easier could be a Stack where you add every < and > symbol on. Afterwards just loop trough it and assert that you don't get the same symbol twice in a row.
This raises the question: how do you distinguish between <MyElement>> and <MyEl>ement>?
This is all pretty vague though: what do you want to happen when the XML turns out to be invalid? How far do you want to take this pre-processing validation?
I believe that the best option here is to not proceed. You can't fix every issue with malformed XML thrown at you and it might just be better to inform the user and make that the end.
If the source is consistently sending malformed XML at you, you'll have to contact the maintainers or look for alternatives.
As others have mentioned - there are a couple of things to do here:
Step 1 - Find out whether XML is malformed on not. For both Element and Value (or Attribute)
Solution: Use Regex or load through String Builder and parse/look for characters (Regex is always better)
Step 2: You can also form an XSD if you want to validate that certain elements have always come (bare minimum). Based on workflow - if those dont appear - you can throw error - depends on your workflow
Step 3: Once you have parsed/fixed the XML - you then need to consume the values
Solution: LINQ to XML is really a good approach here to pull values for what you are interested and not malformed

XSLT: transfer xml with the closed tags

I'm using XSLT transfer an XML to a different format XML. If there is empty data with the element, it will display as a self-closing, eg. <data />, but I want output it with the closing tag like this <data></data>.
If I change the output method from "xml" to "html" then I can get the <data></data>, but I will lose the <?xml version="1.0" encoding="UTF-8"?> on the top of the document. Is this the correct way of doing this?
Many thanks.
Daoming
If you want this because you think that self closing tags are ugly, then get over it.
If you want to pass the output to some non-conformant XML Parser that is under control, then use a better parser, or fix the one you are using.
If it is out of your control, and you must send it to an inadequate XML Parser, then do you really need the prolog? If not, then html output method is fine.
If you do need the XML prolog, then you could use the html output method, and prepend the prolog after transformation, but before sending it to the deficient parser.
Alternatively, you could output it as XML with self-closing tags, and preprocess before sending it to your deficient parser with some kind of custom serialisation, using the DOM. If it can't handle self-closing tags, then I'm sure that isn't the only way in which it fails to parse XML. You might need to do something about namespaces, for example.
You could try adding an empty text node to any empty elements that you are outputting. That might do the trick.
Self-closed and explicitly closed elements are exactly the same thing in any regard whatsoever.
Only if somewhere along your processing chain there is a tool that is not XML aware (code that does XML processing with regex, for example), it might make a difference. At which point you should think about changing that part of the processing, instead of the XML generation/serialization part.

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