javascript - Why is jquery's parseXML function failing when the XML looks ok? - Stack Overflow

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I have a pretty simple bit of javascript that attempt to parse the xml I've extracted from the metadata in a jpeg:

var xmlDoc;
try {
    xmlDoc = $.parseXML(xmlString);
} catch(e) {
    console.log(e);
}

Here is the exception that gets thrown:

Invalid XML: <x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="XMP Core 4.4.0">
   <rdf:RDF xmlns:rdf="">
      <rdf:Description rdf:about=""
            xmlns:photoshop=".0/">
         <photoshop:Instructions>C1DDZVs9Sr+DG5R9eSc%9w</photoshop:Instructions>
      </rdf:Description>
      <rdf:Description rdf:about=""
            xmlns:aux=".0/aux/">
         <aux:SerialNumber>1</aux:SerialNumber>
         <aux:Lens>AF-S DX VR Zoom-Nikkor 18-200mm f/3.5-5.6G IF-ED [II]</aux:Lens>
         <aux:LensID>1</aux:LensID>
         <aux:ImageNumber>6651</aux:ImageNumber>
         <aux:FlashCompensation>0/1</aux:FlashCompensation>
      </rdf:Description>
   </rdf:RDF>
</x:xmpmeta>

There doesn't seem to be anything wrong with that XML. In fact, if I cut and paste that xml in directly, no exception is thrown:

var xmlDoc;
try {
    xmlDoc = $.parseXML('<x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="XMP Core 4.4.0">       <rdf:RDF xmlns:rdf="">          <rdf:Description rdf:about=""                xmlns:photoshop=".0/">             <photoshop:Instructions>C1DDZVs9Sr+DG5R9eSc%9w</photoshop:Instructions>          </rdf:Description>          <rdf:Description rdf:about=""                xmlns:aux=".0/aux/">             <aux:SerialNumber>1</aux:SerialNumber>             <aux:Lens>AF-S DX VR Zoom-Nikkor 18-200mm f/3.5-5.6G IF-ED [II]</aux:Lens>             <aux:LensID>1</aux:LensID>             <aux:ImageNumber>6651</aux:ImageNumber>             <aux:FlashCompensation>0/1</aux:FlashCompensation>          </rdf:Description>       </rdf:RDF>    </x:xmpmeta>' );
} catch(e) {
    console.log("error parsing xml: " + e);
}

I can only assume that there must be some kind of unprintable special character in there somewhere that is causing the trouble. How can I test that assumption and fix it, or perhaps something else is wrong?

I have a pretty simple bit of javascript that attempt to parse the xml I've extracted from the metadata in a jpeg:

var xmlDoc;
try {
    xmlDoc = $.parseXML(xmlString);
} catch(e) {
    console.log(e);
}

Here is the exception that gets thrown:

Invalid XML: <x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="XMP Core 4.4.0">
   <rdf:RDF xmlns:rdf="http://www.w3/1999/02/22-rdf-syntax-ns#">
      <rdf:Description rdf:about=""
            xmlns:photoshop="http://ns.adobe./photoshop/1.0/">
         <photoshop:Instructions>C1DDZVs9Sr+DG5R9eSc%9w</photoshop:Instructions>
      </rdf:Description>
      <rdf:Description rdf:about=""
            xmlns:aux="http://ns.adobe./exif/1.0/aux/">
         <aux:SerialNumber>1</aux:SerialNumber>
         <aux:Lens>AF-S DX VR Zoom-Nikkor 18-200mm f/3.5-5.6G IF-ED [II]</aux:Lens>
         <aux:LensID>1</aux:LensID>
         <aux:ImageNumber>6651</aux:ImageNumber>
         <aux:FlashCompensation>0/1</aux:FlashCompensation>
      </rdf:Description>
   </rdf:RDF>
</x:xmpmeta>

There doesn't seem to be anything wrong with that XML. In fact, if I cut and paste that xml in directly, no exception is thrown:

var xmlDoc;
try {
    xmlDoc = $.parseXML('<x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="XMP Core 4.4.0">       <rdf:RDF xmlns:rdf="http://www.w3/1999/02/22-rdf-syntax-ns#">          <rdf:Description rdf:about=""                xmlns:photoshop="http://ns.adobe./photoshop/1.0/">             <photoshop:Instructions>C1DDZVs9Sr+DG5R9eSc%9w</photoshop:Instructions>          </rdf:Description>          <rdf:Description rdf:about=""                xmlns:aux="http://ns.adobe./exif/1.0/aux/">             <aux:SerialNumber>1</aux:SerialNumber>             <aux:Lens>AF-S DX VR Zoom-Nikkor 18-200mm f/3.5-5.6G IF-ED [II]</aux:Lens>             <aux:LensID>1</aux:LensID>             <aux:ImageNumber>6651</aux:ImageNumber>             <aux:FlashCompensation>0/1</aux:FlashCompensation>          </rdf:Description>       </rdf:RDF>    </x:xmpmeta>' );
} catch(e) {
    console.log("error parsing xml: " + e);
}

I can only assume that there must be some kind of unprintable special character in there somewhere that is causing the trouble. How can I test that assumption and fix it, or perhaps something else is wrong?

• javascript
• jquery
• xml
• debugging
• parsing

Share Improve this question Follow asked Feb 16, 2012 at 16:39 matt burnsmatt burns 25.5k1313 gold badges111111 silver badges108108 bronze badges 2

• 1 Note that jQuery itself doesn't parse XML at all - the browser does. – Pointy Commented Feb 16, 2012 at 16:40
• @Pointy, good point. This was failing in Chrome. I tried in FireFox and it parses ok. Now what can I do?!! Arg! – matt burns Commented Feb 16, 2012 at 16:58

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3 Answers 3

Sorted by: Reset to default 5

I've found the problem. As I suspected, there was some nasty unprintable character lurking at the end of the string.

I was able to remove it with this dirty bit of hacking:

xmlString = xmlString.substr(xmlString.indexOf("<"), xmlString.lastIndexOf(">") + 1);

If it's not obvious, it simply trims away anything from the start and end of the string that isn't the expected angle brackets of an xml document. The jQuery function "trim()" was not effective at removing the rogue character as that only does whitespace.

I don't know what the character was, and I'm not particularly happy with my solution, but I'm too busy to spend more time on it. Sigh.

By using this website http://www.xmlvalidation., I got the following error message, make sure you check the box "Validate against external XML schema "

An error has been found! 

1:  62  cvc-elt.1: Cannot find the declaration of element 'x:xmpmeta'.

XML document: 
1   <x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="XMP Core 4.4.0">
2      <rdf:RDF xmlns:rdf="http://www.w3/1999/02/22-rdf-syntax-ns#">
3         <rdf:Description rdf:about=""
4               xmlns:photoshop="http://ns.adobe./photoshop/1.0/">
5            <photoshop:Instructions>C1DDZVs9Sr+DG5R9eSc%9w</photoshop:Instructions>
6         </rdf:Description>
7         <rdf:Description rdf:about=""
8               xmlns:aux="http://ns.adobe./exif/1.0/aux/">
9            <aux:SerialNumber>1</aux:SerialNumber>
10           <aux:Lens>AF-S DX VR Zoom-Nikkor 18-200mm f/3.5-5.6G IF-ED [II]</aux:Lens>
11           <aux:LensID>1</aux:LensID>
12           <aux:ImageNumber>6651</aux:ImageNumber>
13           <aux:FlashCompensation>0/1</aux:FlashCompensation>
14        </rdf:Description>
15     </rdf:RDF>
16  </x:xmpmeta>

Maybe your problem is:
you can't use XML functions (in JS) on file that have no XML header.
try to open the XML file/input in the browser (type the path in the address bar),
and see if it opened as xml file or like text file.

for emample, adding XML header with php:

header ("Content-Type: text/xml");

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