I just came across with a problem using XmlDocument.LoadXml.
The application was crashing, giving the following error:
"Data at the root level is invalid. Line 1, position 1"
After inspecting the XML and finding nothing wrong with it, I googled a bit and found a tip to use XmlDocument.Load instead of XmlDocument.LoadXml.
I have tried it and it works perfectly.
My question is: What is the difference between the 2 methods and what could have cause one to work and the other to fail?
XmlDocument.Load is used to load XML either from a stream, TextReader, path/URL, or XmlReader.
XmlDocument.LoadXml is used to load the XML contained within a string.
They're fundamentally different ways of loading XML, depending on where the XML is actually stored. So it sounds like you were using the wrong method for where your XML is.
Were you trying to use XmlDocument.LoadXml and passing in the name of a file? It doesn't do that - it assumes that the string you pass in is the XML. So you might use:
doc.LoadXml("<root><child /><root>");
or
doc.Load("myfile.xml");
If that doesn't help, could you show your failing and working code? There are different ways you could have changed from using LoadXml to Load...
Load() loads from a certain source, whereas LoadXml() loads directly from a string
Assuming your using XmlDocument.Load and XmlDocument.LoadXml in the right way this problem may be caused by Byte Order Mark.
This other question might be useful.
The application was crashing with the following error: "Data at the root level is invalid. Line 1, position 1"
I suspect you xml data does not have a root level:
for example:
<area id="1">
<candidate id="0">dataata</candidate>
</area>
<area id="2">
<candidate id="0">dataataa</candidate>
</area>
you need have at least one root level on top of the bottom levels.
for example:
<areas>
<area id="1">
<candidate id="0">dataata</candidate>
</area>
<area id="2">
<candidate id="0">dataataa</candidate>
</area>
</areas>
so please put one mother on the top of your level, make it grand grand mother of all children
Related
Probably another easy one but I cant find the answer and cant work it out.
I have a outerxml packet for example
<field1 id="abc" passed="False">
<field2 id="BCD" reason="yada"/>
</field1>
in asp.net (c#) how can I retrieve the value of "reason"?
You can use LINQ to XML:
string reason = (string)xml.Element("field1").Element("field2").Attribute("reason");
supposing O have these two equivalent (at least they are supposed to be) XML schemas. The actual XML will eventually be parsed by C#. I think the second way is 'more correct' since I will get attributes as actual attrbutes, instead of child elements, correct?
<?xml version="1.0" encoding="ISO-8859-1"?>
<switch>
<switch_name>switch1</switch_name>
<software_version>1</software_version>
<vendor>Cisco</vendor>
<ip_address>1.1.1.1</ipaddress>
<linecard>
<model_type>12345</model_type>
<fcport>
<slot> 1</slot>
<port> 1</port>
<speed>4</speed>
</fcport>
</linecard>
</switch>
<switch>
<switch name="switch1" version="1" vendor="Cisco" ip_address="1.1.1.1">
<linecard model="12345">
<fcport slot="1" port="1" speed="4">
</fcport>
<linecard>
</switch>
</xml>
Neither one is strictly more "correct" than the other, both will work for your example. Neither breaks any rules.
That said, I think I agree with W3Schools on this one, in that data should go inside child elements rather than attributes. Especially things like IP addresses just FEEL like data that should be a child element rather than an attribute. Attributes I typically use for metadata, such as auto generated IDs.
This is especially true if you later want to account for expansion -- for example, what if you want to associate multiple IPs? With child elements you can just add another element, but with attributes you have to come up with a new attribute name for each addition (ip1, ip2, ip3...).
There are no "right" way of representing data in XML when choosing between using elements or attributes for properties of an entity. Choose whatever works for you.
Generally elements give more freedom as you may have sub-elements eventually. I.e. if property is list of some sort representing it as comma-separated value in attribute looks very non-XML.
Side note: "XML schema" usually means different thing - structured schema for XML... what you have I'd call "representation of data in XML".
The classic article on how to choose between elements and attributes is here:
http://xml.coverpages.org/elementsAndAttrs.html
I note that at the end of the page it quotes John Cowan quoting me: "Beginnners always ask this question. Those with a little experience express their opinions passionately. Experts tell you there is no right answer'."
I'm stuck on a subtle problem. I try to build a C# 4.0 console application to read an XML file with.
The XML file is as follow:
<?xml version="1.0" encoding="UTF-8"?>
<?xml:stylesheet type='text/xsl' href='report.xsl' version='1.0'?>
...
<logs>
...
</logs>
And this is my code:
...
var root = XDocument.Load(xmlStream);
IEnumerable<XElement> address =
from el in root.Descendants("formated-text")
select el;
...
This gives me the following error at the Load method:
The ':' character, hexadecimal value 0x3A, cannot be included in a name. Line 2, position 6.
Changing the colon on the second line to a '-' solves the error ... duh
What can I do in my code to read the source XML without having to replace that 'stupid' colon first?
Thank you!
It looks to me like you simply have an invalid XML document. The colon should be a hyphen (as per W3C). I doubt that you'll be able to make LINQ to XML parse an invalid document - and you shouldn't try. You should fix the document instead.
The colon is wrong, you should be using the dash
See http://www.w3.org/Style/styling-XML.en.html
Nothing. That "stupid colon" is simply invalid at that position.
You XSL-Stylesheet element is incorrect.
It should be:
<?xml-stylesheet type='text/xsl' href='report.xsl' version='1.0'?>
Try validating your XML against any number of online validators.
You can try loading the XML as a string and fixing this issue using string parsing, or you could read the original file line by line and fix any occurences of xml:stylsheet before saving it like the text file in this example, but it would be better to get whomever created the XML to fix it at source.
I found out that the origin of these 'malformed' XML files dates back to the mid 1990's ... yes, such an old system is today still in use and still produces this output. I can live with a workaround in my code.
Thank you for taking time to provide some usefull clues at what was/is going on with these XML elements.
I needed this confirmation that the creator of the source XML did a mistake with that colon.
I already have implemented a plan B, until I can convince a really big department (not mine) to make the change in their application ... :o(
Plan B is to read the XML file first and replace all 'xml:' occurences. Then feed this corrected file into my process.
I have a xml file that looks like this :
<?xml version="1.0" encoding="utf-8"?>
<config>
<node id="1" />
</config>
Now I try to deserialize it, but always get the error :
<config xmlns=''> was not expected
Anyone how to fix this ? I dont have any control over the xml.
Thanx
Why not just load it in as a DOM (e.g. using XmlDocument or XDocument) and extract the data yourself? Assuming it wasn't saved with XmlSerializer, there's no point in trying to deserialize it that way.
EDIT: It would help if you'd give us some background here. If this isn't a valid XmlSerializer output, what is it? Was it originally a valid file, but something has stripped out the namespaces? If so, what else has it done?
You may well be able to get away with just reapplying the namespace everywhere yourself (to every element) although that may be annoying do. Currently we can't really tell though.
I am creating an XML file in C# using a XSD Schema of an InfoPath form.
When I save the IP form without using the code, I get an XML file with the following header:
<?xml version="1.0" encoding="UTF-8"?>
<?mso-infoPathSolution solutionVersion="1.0.0.113" productVersion="14.0.0" PIVersion="1.0.0.0" href="file:///\\Hmfp\mcs-shared\PMU\PMU-shared\Tests\QF%207.5%20PMU%20Project%20Outline%20Form%20F1.0.xsn" name="urn:schemas-microsoft-com:office:infopath:QF-7-5-PMU-Project-Outline-Form-F1-0:-myXSD-2010-07-22T07-48-32" ?>
<?mso-application progid="InfoPath.Document"?>
<my:myFields...
And this file is recognized by InfoPath and uses the correct XSD, thus displaying the XML data in the correct form.
But when I use the code, I get this:
<?xml version="1.0"?>
<myFields...
And this is not recognized nor opened directly by InfoPath; so I would like to insert the two tags in order to keep that functionality, so that the users do not see the difference.
My line of thought is to modify the XML file after it has already been created, saved and closed.
It would be very nice if you could help :D. Thanks in advance..
EDIT: I've finally been able to achieve what I wanted. I made use of both MainMa's and dahlbyk's answers and came up with something that works:
I let the file get saved like before
I created an XmlReader object from the file
I loaded the XmlReader into an XmlDocument object
I created an XmlProcessingInstruction object using XmlDocument.CreateProcessingInstruction
I inserted that PI in the XmlDoc using xmlDoc.InsertAfter(thePI, XmlDoc.FirstChild)
I then created a second PI object
Which I inserted using xmlDoc.InsertAfter(thePI, XmlDoc.FirstChild.NextSibling)
Then I saved the XmlDoc in the file, overwriting it
Anyway, your answers helped me understand many things, which made me find the answer, so thank you very much!!
I would try making an XmlWriter for your FileStream, use WriteProcessingInstruction() to add your headers, then pass the writer into the appropriate overload of Serialize() to capture the rest of the output.
The first three lines of your first code sample are called XML processing instructions (PI). So if you are creating your output XML with XmlDocument, you can use XmlDocument.CreateProcessingInstruction method to add the required PI.
If you are serializing into XML, you can also use XmlTextWriter.WriteProcessingInstruction just before serializing the object.
If for some reasons, you cannot do that, you can also save the file, open it and insert two PI after the first line break, but I highly discourage you to do that, since it will make your code difficult to maintain in future, and slow things down.