dhis2-devs team mailing list archive

[Knut Staring <knutst@xxxxxxxxx>]

On Wed, Nov 11, 2009 at 6:14 PM, Knut Staring <knutst@xxxxxxxxx> wrote:

> Not too promising:
>
> "If you expect the number of your point to grow beyond ~100, you'll
> definitely be better off using WMS (especially if your users are on Internet
> Explorer)"



Actually, this 6 month old comment may be a bit outdated, seeing as the
newest browsers handle Javascript a hell of a lot better than a year or two
ago.

I just tried your file with Opera 10 and Firefox 3.5 using
http://openlayers.org/dev/examples/vector-formats.html, and it had no
problem handling it at all.

So in situations where you can tell people to use a modern browser (even IE6
could in fact handle your 1511 features, just takes forever to load... and
is very sluggish) we may be ok.

I still think having an alternative with either static or dynamically
generated SLDs is needed (but not in all situations).

Knut





>
> http://openlayers.org/pipermail/users/2009-March/010997.html
>
> On Wed, Nov 11, 2009 at 5:48 PM, Knut Staring <knutst@xxxxxxxxx> wrote:
>
>> Given that your json file is less than 600 k, it seems to me that it is
>> the number of objects in the DOM that are a problem rather than the file
>> size...which would not be the case with WMS of course, but then, less
>> immediate interaction
>>
>>
>> On Wed, Nov 11, 2009 at 5:38 PM, Knut Staring <knutst@xxxxxxxxx> wrote:
>>
>>> On Wed, Nov 11, 2009 at 5:21 PM, Jason Pickering <
>>> jason.p.pickering@xxxxxxxxx> wrote:
>>>
>>>> In my spare time sitting in a long meeting, I have been taking  a look
>>>> at the GIS module in a bit more detail. I have a few comments.
>>>>
>>>> My source data file is here..
>>>>
>>>>
>>>> http://zamdhis.dynalias.org/geoserver/wfs?request=GetFeature&typename=who:HFC_GPS_ZAMBIA&outputformat=json&srsname=EPSG:4326
>>>>
>>>> This is the GeoJSON output of facilities in Zambia (those that are
>>>> available).
>>>>
>>>> Now, because we are using the DHIS 1.4 naming convention, where a
>>>> prefix of the province has been added to the name of the facility. The
>>>> basic problem here is that there are differences between the names of
>>>> the facilities in the DB and the names in the GeoJSON files. Luckily,
>>>> there is a common code that would allow the data to be matched, but I
>>>> can only match the JSON file on the name of the facility. Possible
>>>> solutions? Change the source file is an option. Allowing matching on
>>>> another field in the database would be a better option perhaps.
>>>>
>>>> Also, since there are some 1500 points or so in the file, the browser
>>>> "greys out" sometimes, which seems really to be a performance issue.
>>>> Obviously, we cannot simplify point files, which can speed up the
>>>> performance of polygon layers in the client. Thoughts?
>>>>
>>>
>>> You can actually simplify even points by including fewer decimals for
>>> each coordinate. That may be acceptable in some situations, but probably
>>> quite undesirable in others - and I think it underscores that we need to
>>> bring the OpenHealth-FP solution of generating SLDs to feed to Geoserver
>>> back in as a supplement for cases where GeoJSON are not suitable. It would
>>> be great to avoid that, but not sure if it is possible when we deal with
>>> serious amounts of data.
>>>
>>> Knut
>>>
>>>
>>>> Regards,
>>>> jason
>>>>
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>>>>
>>>
>>>
>>>
>>> --
>>> Cheers,
>>> Knut Staring
>>>
>>
>>
>>
>> --
>> Cheers,
>> Knut Staring
>>
>
>
>
> --
> Cheers,
> Knut Staring
>



-- 
Cheers,
Knut Staring