Re: [aprsfi] KML overlay capability

[Heikki Hannikainen]

On Fri, 12 Oct 2012, KE5STL wrote:

> aprs.fi is *such* a great web site and service.  Kudos to the creator/maintainers.

Thanks, I'm happy you like it.

> the *one thing* it really needs though, to make it *very* useful for tracking in support of events, is to be able to
> specify a KML file from which a KML layer is added to the map.

I googled "kml aprs.fi" and found this (quickest way to find it for
myself, too :):

http://blog.aprs.fi/2010/10/kml-overlay-support.html

Should add it to the user guide, it's missing from there.

- Hessu

[KE5STL]

hello Hessu,

 

Thank you for replying.

 

I have a bit of a problem getting this to work.

 

Based on the site you've pointed me towards, I am guessing that the below might be supposed to work?

 

I tried uploading to google drive a KML file (here) and tried using the URL of:

 

http://aprs.fi/#!lat=30.1754&lng=-95.3981&kml=http://docs.google.com/uc?authuser=0&id=0B5Jz2LFxTWyuQ1Y0Y0JFMU8zMXM&export=download

 

but alas, it does not seem to work.

 

can you help please?

 

all the best,

Peter

[Heikki Hannikainen]

On Sat, 13 Oct 2012, KE5STL wrote:

> Based on the site you've pointed me towards, I am guessing that the below might be supposed to work?
>
> I tried uploading to google drive a KML file (here) and tried using the URL of:
>  
> http://aprs.fi/#!lat=30.1754&lng=-95.3981&kml=http://docs.google.com/uc?authuser=0&id=0B5Jz2LFxTWyuQ1Y0Y0JFMU8zMXM&export=d
> ownload

You need to URL parameter encode the KML url, so that it doesn't contain
the same special characters as the aprs.fi URL (:/?&=). See closely the
example shown on the page:

http://blog.aprs.fi/2010/10/kml-overlay-support.html

kml=http://he.fi/misc/pentagon.kml

becomes

kml=http%3A%2F%2Fhe.fi%2Fmisc%2Fpentagon.kml

- Hessu

[KE5STL]

hmmmm.

 

well, some of what you've supplied may in fact be being done by the browser for me.

 

if I post the following into the web browser, I do get 'some' of the content of the kml drawn, but not 'all' of it.

 

http://aprs.fi/#!lat=30.1754&lng=-95.3981&kml=https://docs.google.com/uc?id=0B5Jz2LFxTWyuQ1Y0Y0JFMU8zMXM&export=download

 

if you try downloading the kml and viewing it in either google earth, or, importing the kml into google maps to create a custom map, this has no issues showing the entire content of the kml.

 

any ideas?

 

regards,

peter

 

[Heikki Hannikainen]

On Sat, 13 Oct 2012, KE5STL wrote:

> well, some of what you've supplied may in fact be being done by the browser for me.

Sorry, but no, it's not, it cannot be done by the browser at this point.

> if I post the following into the web browser, I do get 'some' of the
> content of the kml drawn, but not 'all' of it.  
> http://aprs.fi/#!lat=30.1754&lng=-95.3981&kml=https://docs.google.com/uc?id=0B5Jz2LFxTWyuQ1Y0Y0JFMU8zMXM&export=download

URL encode the parts after kml= and it works fine - I tried.

Here's a reference for the special characters:

http://www.w3schools.com/tags/ref_urlencode.asp


http://aprs.fi/#!lat=30.1754&lng=-95.3981&kml=https%3A%2F%2Fdocs.google.com%2Fuc%3Fid%3D0B5Jz2LFxTWyuQ1Y0Y0JFMU8zMXM%26export=download

- Hessu

[KE5STL]

ok.

 

lets say I use the URL that you've suggested I use.

 

now.

 

look at the map that is displayed.

 

notice the blue markers?

 

there is a gap between 9 and 30.  the course runs clockwise.

 

in the KML file, there is no gap.  every station is shown.

 

why are they missing from aprs.fi

 

?

 

if you download the kml, and view it directly in google earth (for example), all of the stations are shown.

 

(thank you very much for working with me on this - your help is appreciated!)

 

best regards,

peter

 

[KE5STL]

Heikki,

 

I posted a query about the incomplete display of the KML layer over on the google maps forums, and got a response that it's a known issue.

 

It appears that it's a manifestation of an issue with server-side rendering within google's functionality.

 

I asked whether it's possible to force client-side rendering instead of allowing the google api to send it off to the server for rendering, and, essentially, I got pointed towards this site, which offers what could be termed a predecessor to the now available kml markup support.

 

http://code.google.com/p/geoxml3/

 

essentially it's a 3rd party javascript library (well, multiple versions, in fact) that seem to totally do the drawing on the client.

 

I wonder if you could look into this as an option?

 

not perhaps so much as to completely replace / supplant the google supported (well, ahem, perhaps not) kml layer functionality, but, it could sit along side or be made available as an option so that users can choose which one gets used.

 

all the best,

peter

 

[KE5STL]

hello Heikki,

 

did you get to try the kml and observe the issue?

 

did you take a look at the geoxml3 javascript library?

 

best regards,

peter

[Heikki Hannikainen]

Hi,

On Thu, 25 Oct 2012, KE5STL wrote:

> did you get to try the kml and observe the issue?

Yes. Maybe some data is missing from it (I didn't load it in Google
Earth).

aprs.fi simply passes the KML URL to the Google Maps API code, so if some
KML features are not handled, that's a defect in Google Maps itself.

> did you take a look at the geoxml3 javascript library?

No, unfortunately I don't have time to look into that right now.

- Hessu

[KE5STL]

The point of having you try the KML in Google Earth is exactly so that you will see for yourself that Google Maps is messing up.  Google Maps is *not rendering all of the KML content*.

 

It's a problem that Google Maps evidently has, and has had for a while.

 

take a look at this google maps forum thread I started regarding this issue:

 

http://productforums.google.com/forum/#!mydiscussions/maps/kKJYMCLCM60

 

regards,

peter