Check XML node exists by Value using JQuery

Question

Hi,

I'm trying to check if a value in an xml node exists using Jquery. The xml string is:

  <SectionAnswers>
   <SectionAnswer>
    <detailID>2216</detailID>
    <SourceAnswerID>979</SourceAnswerID>
   </SectionAnswer>
   <SectionAnswer>
    <detailID>2218</detailID>
    <SourceAnswerID>981</SourceAnswerID>
   </SectionAnswer>
   <SectionAnswer>
    <detailID>2219</detailID>
    <SourceAnswerID>977</SourceAnswerID>
   </SectionAnswer>
   <SectionAnswer>
    <detailID>2221</detailID>
    <SourceAnswerID>980</SourceAnswerID>
   </SectionAnswer>
   <SectionAnswer>
    <detailID>2282</detailID>
    <SourceAnswerID>64</SourceAnswerID>
   </SectionAnswer>
   <SectionAnswer>
    <detailID>2283</detailID>
    <SourceAnswerID>978</SourceAnswerID>
   </SectionAnswer>
   <SectionAnswer>
    <detailID>2596</detailID>
    <SourceAnswerID>73</SourceAnswerID>
   </SectionAnswer>
  </SectionAnswers>

When I try to query it for a value by using the following:

$("SectionAnswers", Section).find("64") //Section is the jquery context

I get the following response:

Expression does not return a DOM node.

.//-->64<--

Any ideas where I'm going wrong with this? I really don't want to loop through them checking the value each time as in $("SectionAnswers", Section).each()

Thanks

Answer 1

I'm leaving this here for reference, since it could be useful in slightly different circumstances, but, like karim79 mentioned, it matches anything that has 64 as a substring.

---

You should be able to use the ":contains(text)" pseudo-selector:

$("SectionAnswers SourceAnswerID:contains('64')", Section)

That will select the SourceAnswerID elements, so you might need to use the parent() or closest() function to move up the hierarchy.

Answer 2

Try traversing the XML using a simple $.each:

$('SectionAnswers > SectionAnswer').each(function() {
    if($(this).find('SourceAnswerID').text() == '64') {
        alert('Found 64 at detailID: ' + $(this).find('detailID').text());
    }
});

or using filter:

var $sa = $('SectionAnswers > SectionAnswer').filter(function() {
    return $(this).find('SourceAnswerID').text() == '64'; 
});
alert($sa.find('SourceAnswerID').text());
alert($sa.find('detailID').text());

Answer 3

Thanks guys.

I'll play around with both of those and see what I can come up with. I want to avoid a loop if possible because it will already be running inside of a loop and I just have a button about nested loops...

But now that I think about it... Both the filter and contains calls are loops internally anyways... So it might actually perform better it just simply get the collection and iterate through it.

Answer 4

OK got a fix. I ended up changing the xml to make the IDs attributes so it is

  <SectionAnswers>
   <SectionAnswer SourceAnswerID="1487"
         detailID="1420" />
   <SectionAnswer SourceAnswerID="1488"
         detailID="2039" />
  </SectionAnswers>

And I can now find it via

find("SectionAnswer[SourceAnswerID=1487]")

It's a better solution anyway as putting the info in attributes cuts down on the size of the return value.