[OpenLayers-Users] Best option for visualizing JSON

[Lehtonen, Mika]

Hi again,
actually I might have been barking the wrong tree. This is what seem not 
to be working in IE7.

function selectAll()        {
                req = OpenLayers.Request.issue({
                method: 'GET', url:'http://mydomain/my.php',
                headers:{"Content-Type": 
"application/x-www-form-urlencoded"},
                callback: json
                 });
                }

It works at the start, but the second attempt in IE7 won't return 
anything. So that's why the newly inserted row won't update my map. Is 
there something wrong with that request?

- mika -

Lehtonen, Mika kirjoitti:
> Thanks Christopher,
> for your answer. However, beacuse there's not so many points and I have 
> to put this together quickly and because this is just a temporary 
> solution, I ended up adding points onto a vector layer one by one. So 
> here's the function that does that:
>
> function json(req) {
>     g =  new OpenLayers.Format.JSON();
>     vastaus = g.read(req.responseText);
>     vlayer.destroyFeatures();
>     for (i in vastaus) {
>     piste = new OpenLayers.Geometry.Point(vastaus[i].x, vastaus[i].y);
>     spot = new OpenLayers.Feature.Vector(piste,{id: vastaus[i].id});
>     vlayer.addFeatures(spot);
>     }
>      // vlayer.redraw(true);
>     }
>
> Behind this, is an OpenLayers.Request that requests the json from 
> database using php-script for that. I also have a function which adds 
> points to the database. This all works fine in FF3, but not in IE7. If I 
> add a point in IE, it won't appear until I restart the browser. Even 
> reloading the page won't help. Still if, after I have added the point in 
> IE, I reload the page in FF3, the newly added point appears in it.
> Any idea what's wrong?
>
> - mika -
>
> Christopher Schmidt kirjoitti:
>   
>> On Wed, Jan 07, 2009 at 11:28:37PM +0200, Lehtonen, Mika wrote:
>>   
>>     
>>> Hi,
>>> I have some JSON data produced from an "ordinary" database. Basically 
>>> it's an array having objects that include x-, y- and some attribute values.
>>>
>>> What would be the best way to render these x-, y-values as points or 
>>> markers in Openlayers. Should I use Marker or Vector or what layer? Any 
>>> Examples?
>>>     
>>>       
>> I'd recommend turning the data into GeoJSON on the server, then using a
>> Vector Layer with the HTTP Protocol and the GeoJSON format
>> (alternatively, a GML Layer with a GeoJSON format). If you really can't
>> do that, then you could write a custom subclass o the JSON format,
>> basing it of something like the GeoJSON format, and follow either of the
>> above options with your custom format.
>>
>> Regards,
>>   
>>     
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