Can you use dot notation in JS object with special characters in the key name

Question

I am using the xml2js module to parse an xml file into a JS object. The xml document uses namespaces in all the nodes. A snippet of the file looks like this:

<resource identifier="604262" type="imsqti_item_xmlv2p1" href="604262.xml">
        <metadata>
            <imsqti:qtiMetadata>
                <imsqti:timeDependent>false</imsqti:timeDependent>
                <imsqti:interactionType>choiceInteraction</imsqti:interactionType>
                <imsqti:feedbackType>none</imsqti:feedbackType>
                <imsqti:solutionAvailable>true</imsqti:solutionAvailable>
            </imsqti:qtiMetadata>
            <imsmd:lom>
                <imsmd:general>
                    <imsmd:identifier>604262</imsmd:identifier>
                    <imsmd:parentId>627617</imsmd:parentId>
                    <imsmd:classicId>16211</imsmd:classicId>
                    <imsmd:classicParentId>238933</imsmd:classicParentId>
                    <imsmd:passageId>650453</imsmd:passageId>
                    <imsmd:classicPassageId>16203</imsmd:classicPassageId>
                    <imsmd:depthOfKnowledge></imsmd:depthOfKnowledge>
                    <imsmd:bloomsLevel></imsmd:bloomsLevel>
                    <imsmd:omit>false</imsmd:omit>
                    <imsmd:replaceWith></imsmd:replaceWith>
                    <imsmd:allowCalculator>0</imsmd:allowCalculator>
                    <imsmd:allowGrammarTools>0</imsmd:allowGrammarTools>
                    <imsmd:displayFormatId></imsmd:displayFormatId>
                    <imsmd:forceFullPage>0</imsmd:forceFullPage>
                    <imsmd:itemTypeId>3</imsmd:itemTypeId>
                    <imsmd:mediaTypeId>1</imsmd:mediaTypeId>
                    <imsmd:consortiumId>1</imsmd:consortiumId>
                    <imsmd:useTwoPointScoring></imsmd:useTwoPointScoring>
                    <imsmd:parccTwoPointScoring></imsmd:parccTwoPointScoring>
                </imsmd:general>

When this is converted to JSON I end of with object keys of "imsmd:lom" and "imsmd:general" so when I try to use dot notation to access parts of the object like result.imsmd:lom.imsmd:general I get an error saying unexpected token where the colon is.

I've used the stripPrefix method of the xml2js parser but it's not removing these prefixes. Is there another way to remove the prefixes or is there a different way to traverse the JS object to avoid the error?

score 1 · Accepted Answer · answered Dec 23 '15 at 15:14

1

object.property

is syntax sugar for

object["property"]

So, because object.imsmd:lom isn't a valid identifier, you must use object["imsmd:lom"].

answered Dec 23 '15 at 15:14

Jacob Krall

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how do you access a sub-property though of object["umsmd:lom"] – Jon Luzader Dec 22 '17 at 03:25
@JonLuzader any expression in JavaScript can be subscripted, so you can keep writing property names until you get to the depth you want: `object["imsmd:lom"]["imsmd:general"]["imsmd:consortiumId"]` – Jacob Krall Dec 22 '17 at 13:31
Thanks Jacob! I was able to access the sub properties using your advice – Jon Luzader Dec 23 '17 at 16:02

Can you use dot notation in JS object with special characters in the key name

1 Answers1