What causes this inconsistency in xml parsing?

Question

Nathan Jessurun 2018-7-9

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/409506-what-causes-this-inconsistency-in-xml-parsing

回答： Nathan Jessurun 2018-7-17

I have the following XML file:

<?xml version="1.0" encoding="utf-8"?>
<AddressBook>
 <Entry>
    <Name>Friendly J. Mathworker</Name>
    <PhoneNumber>(508) 647-7000</PhoneNumber>
    <Address hasZip="no" type="work">3 Apple Hill Dr, Natick MA</Address>
 </Entry>
 <Entry>
    <Name>Joe P. Surname</Name>
    <PhoneNumber>(334) 647-8898</PhoneNumber>
    <Address hasZip="no" type="work">123 Addr Lane, Chicago NY</Address>
 </Entry>
 <Entry>
    <Name>Mary Sue Lastname</Name>
    <PhoneNumber>(508) 552-5698</PhoneNumber>
    <Address hasZip="no" type="home">456 Another Addr, Boston OR</Address>
 </Entry>
</AddressBook>

Which I capture in DOM form with

dom = xmlread(file)
xmlEl = dom.getDocumentElement();

There should be 3 first-level children, correct? But when I call

xmlEl.getLength();

the answer is 7!

It gets better: I then call

xmlwrite(dom);

After which xmlEl.getLength returns 3! What is happening here? Any help would be appreciated

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Guillaume 2018-7-9

xml2struct seems to be able to handle that properly. From reading the code, it would appear that it just discards these #text empty children.

Nathan Jessurun 2018-7-9

Thanks for the suggestion! It seems to work fine. Though, it is a shame that a wrapper file has to be used for very simple information extraction. Would it be worth contacting Mathworks, or do they not guarantee any reliable performance for Java-based functions?

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Answer 1

Nathan Jessurun 2018-7-17

0
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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/409506-what-causes-this-inconsistency-in-xml-parsing#answer_329072

Per Guillaume's answer in the a comment above (https://www.mathworks.com/matlabcentral/answers/409506-what-causes-this-inconsistency-in-xml-parsing#comment_587489) - these extra children are text nodes, which represent the literal space in the DOM tree. Undocumented behavior in xmlwrite removes these spaces when printing, which alters the tree and yields the correct number of children.