Ben Nadel
On User Experience (UX) Design, JavaScript, ColdFusion, Node.js, Life, and Love.
I am the chief technical officer at InVision App, Inc - a prototyping and collaboration platform for designers, built by designers. I also rock out in JavaScript and ColdFusion 24x7.
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ColdFusion XmlParse() Error - Content Is Not Allowed In Prolog

By Ben Nadel on
Tags: ColdFusion

I was working on an XML database this weekend and was stuck for a bit on an error getting thrown during an XmlParse() call. The error was:

Content is not allowed in prolog.

The original code was trying to take an XML document object, convert it into a string and then parse it into a ColdFusion query object (for testing). That's where the XmlParse() method call came into play.

  • <!---
  • Try to convert the xml object to an xml string then
  • into a query object the using XmlToQuery() UDF.
  • --->
  • <cfset qData = XmlToQuery( xmlDoc.ToString() ) />

I thought it was a white space problem prior to the XML doctype. I have run into that problem before. I tried to Trim() the content before I sent it in, but that did not help. The issue, I finally worked out, was the "ToString()" method call. I was calling it incorrectly - I always do that! You can't call the method from the XML document object. You have to call it PASSING IN the Xml document:

  • <!---
  • Try to convert the xml object to an xml string then
  • into a query object using the XmlToQuery() UDF.
  • --->
  • <cfset qData = XmlToQuery( ToString( xmlDoc ) ) />

I finally figured this out because dumping out xmlDoc.ToString() resulted in:

#document: null

... which obviously was NOT a string representation of the XML document object.




Reader Comments

I am also having a problem with getting a [#document: null] when attempting to 'save' the xml document to disk -
When i cfdump the xml object it looks fine - (cfmx 7).
But after I do a xmldoc.ToString() on it - the text it saves is the [#document: null].

How can I convert the created XML doc to a String (I had to do some 'funky' things prior to saving this xml doc, like merging it etc - so maybe that would be the cause, but either way, it renders fine in cfdump but I can't get it back to it's String representation.

ideas?

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Ah - ok - I dind't realize toString() could be used like that -
so I did this toString(myxmldoc) and all is good now -

Thanks!

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I realize that this is a posting from a *long* time ago (I added myself to the "use it or lose it" e-mail), but I have run across this error before also. It turned out to be a problem within a webservice that I was writing, but had nothing to do with the "tostring" or with any whitespace before the XML...it just was throwing an error within the code itself, and, because the error was being thrown, was appearing to CF as if there was whitespace before the XML. I guess it makes sense, but it would have been nice if the actual error was thrown also :)

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That's good to know. I don't have much experience with Web Services, so it's good for me to know where possible errors are coming from. But I agree, some of the errors that ColdFusion throws are not exactly the most illuminating.

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Im not using toString, but am getting the same error, occasionally. Thats right occasionally! My webservice works 99% of the time, then I get these odd errors. At first I contributed it to the feed coming back in error, but then my isXML check would have caught that. So as of now, Im stumped.

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In my experiences working with XML, i find that every once in a while, no matter if we cdata nodes or not - some data we get from xml can have high ascii characters in them - which may bomb out at the parse level. The xml may parse just fine in Internet Explorer or Firefox, but when that same xml is given to cf to xmlparse, it will throw an error. Removing of the often hidden character or character that appears in notepad as a 'box' character often fixes the problem -

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Kevin has a good point. In addition to that, make sure that you are using XmlFormat() even for the content that is inside of CDATA[]. You might have to unescape somethings afterwards, though. However, it might help you to narrow down where the problem is.

If its a high-ascii value, I was just blogging on the topic of stripping out ascii values:

http://www.bennadel.com/index.cfm?dax=blog:1155.view

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trim(), extra #, blah blah blah... didn't work but the below works for me:

in CF Admin >> setting >> enable white space management

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take that back....not working my eyes cheated me, only partial better coz at least the xml showing properly now, but still getting that error.

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okay, fixed... if you are developing and can get hold of the xml try creating an empty file with notepad called test.txt. Copy and paste the xml into this .txt and change it into .xml.

You will notice there is an extra 1 byte of code that you can't see that is causing this error.

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I want to also add, that you can get this if you are doing a cfhttp request to a URL that you expect to return XML, but returns something like a 'Connection Failure' or some other invalid data.

I just ran into this - and depending on your environment, can be quite tricky to debug as it may be a network configuration thing and not a code issue at all.

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Hey guys,

I was getting this error today about the prolog. I was trying to do something like:

<cfhttp url="http://maps.google.com/maps/geo?q=#address#&output=xml&key=#GMAP_KEY#" />

<cfset myXml = XmlParse(cfhttp.FileContent)>

The problem was occurring because there was a "#" symbol in the street address.

If anybody does something like this, I would recommend replacing the "#" symbol like this:

<cfset address = '#Replace(address, "##", "", "ALL")#'>

The prolog error went away and now everything is back to normal.

Sincerely,
Travis Walters

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@Travis,

I am not sure I completely follow you; are you saying that the XmlParse() method call was throwing an error because there was a # symbol in the XML string?

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@Ben Nadel,

When the "#" symbol is included in a street address that get sent to the Google server, the cfhttp.FileContent comes back in a strange format that the XMLParse does not interpret correctly.

Error Example:

<cfhttp url="http://maps.google.com/maps/geo?q=2017 Mission Street ##303,San Francisco,California,94110,US&output=xml&key=#GMAP_KEY#" />

<cfset myXml = XmlParse(cfhttp.FileContent)>

Solution:

<cfhttp url="http://maps.google.com/maps/geo?q=2017 Mission Street 303,San Francisco,California,94110,US&output=xml&key=#GMAP_KEY#" />

The error given in the first example is the prolog error. Just thought I would warn people about this glitch I encountered that seemed to go well with your article.

Sincerely,

Travis Walters

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@Travis,

Thanks for clarifying. Looks like they might be sending back a corrupt result of some sort.

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I was having the same issue and this didn't work for me. What did work for me was to call in the xml using cffile:

<cffile action="read" file="#expandPath('pathto/my.xml')#" variable="myxml">
<cfset qData = xmlParse(myxml) />

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