Hi Josh,
it looks like $foo.find(":header") has a problem since there is no
single root element. Wrapping your data packet into <div> would help:
$foo = $("<div>"+foo+"</div>");
but since you are after a speed optimization I would suggest:
layerType = $(queryTarget[0]).text();
This gets the text of your first element, which is your header.
One remark to the speed measurement:
Do you get each packet from a different source type or do they came in
streams from one source?
If you have to do the layer look up for every packet, you have to
account this time to your speed measurement as well.
If you are really after high speed, you could use a pure JavaScript
variant, which is about 25x faster than the original approach in IE.
For that you would have to remove white spaces between your nodes, to
avoid browser quirks.
var $foo = $(foo.replace(/>\s+</g,"><"));
see: http://jsbin.com/ukewu
But be warned, with this optimization you are hard coded to the
current data packet layout and may not even change a point in it!
This is a general remark: optimization goes against readability and
flexibility in most cases.
So you have to decide for every project and optimization step, what's
worth more, speed vs. flexibility / scalability vs. readability /
simplicity
by(e)
Stephan
2009/3/2 Josh Rosenthal <maric...@gmail.com>:
> Hi Stephen,
> My apologies for not getting back to you sooner. I've been sick and my
> projects have gotten away from me.
> We now return to the email I'd started writing before I lost track of
> everything. ....
> Thank you! Trebly so!
> First, yes, the data is ordered based on a template in geoserver that
> produces the KMLs. Unfortunately, I'd simplified the issue in order to ask
> my question. There are actually two parcel sources, which each produce
> different sets of fields. The snippet I included above is from the low
> quality parcels. In the high quality parcels, MAP_ID becomes MAP_PAR_ID,
> (hence my use of MAP_ as my search term). Similarly, the indices change
> depending on the layer.
> However, I can detect which layer i'm using (listed in the header), so in
> theory I could detect and then use indices appropriate to the layer. Mind
> you, on trying this, I can't get $foo.find(":header").text(); to work, so
> I'm not quite sure how to get it to work. - http://jsbin.com/ujoco using
> queryTarget for the second index attempt.
> Given that the name of the fields change, I don't think I can use the hash
> solution in any way other than the if layername == check that I was trying
> before (which in any case requires a .find('header') to work).
> Second, my thanks for the very cool site link. Definitely great for sample
> snippets.
> Thirdly, the sample speed measurement code - one reason for the question in
> the first place was not knowing how to measure speed. The sample helps a
> lot.
> Thanks a lot, and sorry for the delay in responding,
> Josh
>
> On Thu, Feb 19, 2009 at 5:12 AM, Stephan Veigl <stephan.ve...@gmail.com>
> wrote:
>>
>> Hi Josh,
>>
>> are your data ordered? (e.g. MAP_ID is the first <li>, SITE_ADDRESS
>> the second, ...)
>>
>> If yes you can use a index based approach (from 4.8ms to 0.9ms on IE).
>> var $foo = $(foo);
>> var data = $foo.find(".atr-value");
>> var parcelOutput = 'Parcel ID: ' +
>> $(data[0]).text() +
>> '<br>' +
>> 'Address: ' +
>> $(data[1]).text();
>>
>>
>> Otherwise you can build a hash table of your name - value attributes
>> and du a hash lookup (from 4.8ms to 2.7ms on IE)
>> var $foo = $(foo);
>> var names = $foo.find(".atr-name");
>> var data = $foo.find(".atr-value");
>> var hash = {};
>> for (var j=0; j<names.length; j++) {
>> hash[$(names[j]).text()] = $(data[j]).text();
>> }
>> var parcelOutput = 'Parcel ID: ' +
>> hash['MAP_ID'] +
>> '<br>' +
>> 'Address: ' +
>> hash['SITE_ADDRESS'];
>>
>>
>> see my examples on the profiling test page:
>> http://jsbin.com/ifico/edit
>>
>> by(e)
>> Stephan
>>
>>
>> 2009/2/18 Josh Rosenthal <maric...@gmail.com>:
>> > So... a question regarding selector efficiency.
>> > The following snippet of HTML describes attributes associated with a
>> > polygon
>> > in an KML. Its basically a table of data, contained as <span>s in <li>s
>> > in
>> > a <ul>. Given this snippet, what would be the best (fastest) way to
>> > return
>> > the values of MAP_ID and SITE_ADDRESS
>> > foo = "<h4>GISDATA.ASSESSPARNC_POLY_PUBLIC</h4>
>> >
>> > <ul class="textattributes">
>> > <li><strong><span class="atr-name">MAP_ID</span>:</strong> <span
>> > class="atr-value">16-27</span></li>
>> > <li><strong><span class="atr-name">SITE_ADDRESS</span>:</strong> <span
>> > class="atr-value">396 Main St</span></li>
>> > <li><strong><span class="atr-name">SITE_OTHER_FIELD</span>:</strong>
>> > <span
>> > class="atr-value">Grat Data</span></li>
>> > <li><strong><span class="atr-name">USE_CODE</span>:</strong> <span
>> > class="atr-value">101</span></li>
>> > <li><strong><span class="atr-name">TOWN_ID</span>:</strong> <span
>> > class="atr-value">116</span></li>
>> > <li><strong><span
>> > class="atr-name">WARREN_GROUP_05_MAP_ID</span>:</strong>
>> > <span class="atr-value">M:0016 B:0000 L:0027</span></li>
>> > <li><strong><span class="atr-name">ACRES</span>:</strong> <span
>> > class="atr-value">0.67102373655</span></li>
>> >
>> > </ul>"
>> >
>> > The following works
>> > parcelOutput = 'Parcel ID: ' +
>> >
>> > jQuery(foo).find('li:contains("MAP_")').not('li:contains("WARREN_GROUP")').children('.atr-value').text()
>> > + '<br>' + 'Address: ' +
>> >
>> > jQuery(foo).find('li:contains("SITE_ADDRESS")').children('.atr-value').text();
>> > Is there a better/more efficient way to return these values?
>> > Thanks!
>
>
