[OpenLayers-Users] Highlighting the selected geometry
Lehtonen, Mika
mika at digikartta.net
Thu Sep 11 09:34:16 EDT 2008
I got it working. Not the highlighting, but GetFeature. Those of you who
don't know what I have been up to, I've been trying to do what is done
in http://www.openlayers.org/dev/examples/getfeatureinfo.html , but with
GetFeature. With this code I get feature's data by clicking it like in
that example. You can decode the filter e.g. in
http://meyerweb.com/eric/tools/dencoder/ . What was wrong with other
browsers than FF3, was that I forgot apostrophes off around the filter
declaration. In FF3, I noticed that it doesn't care about URL encoding,
just stick your staff into it as it is.
cheers,
mika
map.events.register('click', null, function (e) {
OpenLayers.Util.getElement('nodelist').innerHTML = "Please wait...";
var hiiri = wfs.map.getLonLatFromPixel(e.xy);
var hiirixy = (hiiri.lat+','+hiiri.lon);
var url = wfs.getFullRequestString({
SERVICE: 'WFS',
VERSION: '1.1.0',
REQUEST: 'GetFeature',
OUTPUTFORMAT: 'json',
PROPERTYNAME: 'the_geom,LAYER',
MAXFEATURES: 5,
TYPENAME: 'dikanet:karsa_region',
SRSNAME: 'EPSG:2393',
FILTER:
'%3Cwfs%3AFeatureCollection%20xmlns%3Awfs%3D%22http%3A//www.opengis.net/wfs%22%3E%3Cgml%3AfeatureMember%20xmlns%3Agml%3D%22http%3A//www.opengis.net/gml%22%3E%3CFilter%3E%3CContains%3E%3CPropertyName%3Ethe_geom%3C/PropertyName%3E%3Cgml%3APoint%3E%3Cgml%3Acoordinates%3E%7Bhiirixy%7D%3C/gml%3Acoordinates%3E%3C/gml%3APoint%3E%3C/Contains%3E%3C/Filter%3E%3C/gml%3AfeatureMember%3E%3C/wfs%3AFeatureCollection%3E'
},"http://karsamaki.digikartta.net/asemakaavat/wfs"
);
OpenLayers.loadURL(url,'',this,yourFunction);
Event.stop(e);
});
function yourFunction(response) { // this will only zoom into selected feature..
// alert(response.responseText);
g = new OpenLayers.Format.JSON();
jsonni = g.read(response.responseText);
var rajat = new OpenLayers.Bounds(jsonni.bbox[0],jsonni.bbox[1],jsonni.bbox[2],jsonni.bbox[3]);
map.zoomToExtent(rajat);
};
Lehtonen, Mika kirjoitti:
> Hi Brad,
>
> cool site you have!
>
> You know, I went on with my own style, as stubborn is my middle name.. I
> got my code working so far; to get JSON out of the selected polygon
> (nice thing to move on .. ;-) ), but...
> you don't happen to know how I'll get this working also in IE. Here is
> the snippet. I guess it got something to do with the URL encoding ...?
> Debugger blames the filter, which obviously is the guilty one. (IE excl.
> :-) ).
>
> map.events.register('click', null, function (e) {
> OpenLayers.Util.getElement('nodelist').innerHTML = "Odota hetki...";
> var hiiri = wfs.map.getLonLatFromPixel(e.xy);
> var hiirixy = (hiiri.lat+','+hiiri.lon);
>
> var url = wfs.getFullRequestString({
> SERVICE: 'WFS',
> VERSION: '1.1.0',
> REQUEST: 'GetFeature',
> OUTPUTFORMAT: 'json',
> PROPERTYNAME: 'the_geom,LAYER',
> MAXFEATURES: 5,
> TYPENAME: 'dikanet:karsa_region',
> SRSNAME: 'EPSG:2393',
> FILTER: <wfs:FeatureCollection
> xmlns:wfs="http://www.opengis.net/wfs"><gml:featureMember
> xmlns:gml="http://www.opengis.net/gml"><Filter>
>
> <Contains><PropertyName>the_geom</PropertyName><gml:Point><gml:coordinates>{hiirixy}</gml:coordinates></gml:Point></Contains>
> </Filter></gml:featureMember></wfs:FeatureCollection>
> },
> "http://karsamaki.digikartta.net/asemakaavat/wfs"
> );
> ..............................................
>
> OpenLayers.loadURL(url,'',this,testJSON);
> Event.stop(e);
> });
>
> ............................................
> function testJSON (response) {
> // alert(response.responseText);
> g = new OpenLayers.Format.JSON();
> jsonni = g.read(response.responseText);
> var rajat = new
> OpenLayers.Bounds(jsonni.bbox[0],jsonni.bbox[1],jsonni.bbox[2],jsonni.bbox[3]);
> map.zoomToExtent(rajat);
> };
> ..........................................................
> Doesn't do anything else so far than zooms into the selected polygon.
>
> - mika -
>
>
> Brad Spencer kirjoitti:
>
>> Mika,
>>
>> I typically use getFeature when I need the geometry as well and one way to
>> reduce the number of polygons returned is to set up a Shift-drag event that
>> can be used to reduce the BBox of the GetFeature request to be limited to
>> the user's discretion. However, this will be a rectangle and will probably
>> still return more or less polygons than you need. The request I use
>> typically looks something like this:
>>
>> &typename=MESHBLOCKS&datastore=ABS&service=wfs&request=GetFeature&filter=<Fi
>> lter><BBOX><Box><coordinates>151.042611,-33.947448%20151.043,-33.9</coordina
>> tes></Box></BBOX></Filter>&outputformat=BXFS
>>
>> This returns an GML file into DOM that I can parse to get all the
>> coordinates of the polygons returned.
>>
>> However, if you are interacting via a single clicking process and do not
>> need the geometry then all you need is a getFeatureInfo request. I have
>> built an application that does this see
>> http://demos.numaps.com.au/polypika.html. Just doubleclick any red polygon
>> and what happens in the background is the click generates a getFeatureInfo
>> request which looks something like:
>>
>> REQUEST=GetFeatureInfo&VERSION=1.1.3&SERVICE=WMS&SRS=EPSG:900913&BBOX=128495
>> 99.340828,-3816959.290073,12980306.659172,-3708418.709927&X=474&Y=369&QUERY_
>> LAYERS=INDIGENOUS_LOC:ABS&WIDTH=855&HEIGHT=710&RADIUS=0&FEATURE_COUNT=1&INFO
>> _FORMAT=text/xml
>>
>> This returns a an XML file into the DOM which I can parse to get the Polygon
>> Id. Then I do the SLD thing.
>>
>> Hope these suggestions help you.
>>
>> Cheers, Brad Spencer....
>>
>>
>>
>> -----Original Message-----
>> From: users-bounces at openlayers.org [mailto:users-bounces at openlayers.org] On
>> Behalf Of Lehtonen, Mika
>> Sent: Tuesday, September 09, 2008 10:43 PM
>> To: Openlayers Users List
>> Subject: Re: [OpenLayers-Users] Highlighting the selected geometry
>>
>> Yep,
>> thanks. I am using Geoserver so SLD approach is ok. One stupid question.
>> I started to play around with GetFeature, but how can you get just the
>> feature you clicked. I tried something similar like in OL example [1],
>> but with GetFeature and WFS. So the following is what I tried:
>>
>> map.events.register('click', null, function (e) {
>> OpenLayers.Util.getElement('nodelist').innerHTML = "Odota hetki...";
>> var url = wfs.getFullRequestString({
>> SERVICE: 'WFS',
>> VERSION: '1.0.0',
>> REQUEST: 'GetFeature',
>> OUTPUTFORMAT: 'text/xml; subtype=gml/2.1.2',
>> PROPERTYNAME: 'LAYER',
>> MAXFEATURES: 3,
>> TYPENAME: 'dikanet:karsa_region',
>> SRSNAME: 'EPSG:2393',
>> BBOX: wfs.map.getExtent().toBBOX()},
>> "http://karsamaki.digikartta.net/asemakaavat/wfs"
>> );
>> OpenLayers.loadURL(url,'',this,setHTML);
>> Event.stop(e);
>> });
>>
>> function setHTML(response) {
>> OpenLayers.Util.getElement('nodelist').innerHTML =
>> response.responseText;
>> };
>>
>> But this gives me all the feautures in the current viewport. How can I
>> filter out the rest and just take the one I clicked?
>>
>> - mika -
>>
>> [1] http://www.openlayers.org/dev/examples/getfeatureinfo.html
>>
>> Brad Spencer kirjoitti:
>>
>>
>>> Mika,
>>>
>>> Does the map server support (style Layer descriptors) SLDs? If so this is
>>> the best way to highlight polygons in my experience. Vectors may misalign
>>> depending on browsers/projections. Also there are capacity limits on
>>>
>>>
>> vectors
>>
>>
>>> at the client which can be problematic. The easiest way to make sure this
>>> does not happen is to have the layer render again via a new SLD. What I do
>>> is run a GetFeatureinfo(WMS) or getfeaturte(WFS) bring back the list of
>>> polygons (must have unique identifiers) then I build an SLD on the fly via
>>>
>>>
>> a
>>
>>
>>> PHP script save it and then apply that to the current layer. Of course if
>>> you have the polygon names already accessible in the client (e.g. in a
>>> select box) then you can just jump to the SLD building part. Works a
>>>
>>>
>> treat.
>>
>>
>>> Cheers, Brad....
>>>
>>> -----Original Message-----
>>> From: users-bounces at openlayers.org [mailto:users-bounces at openlayers.org]
>>>
>>>
>> On
>>
>>
>>> Behalf Of Lehtonen, Mika
>>> Sent: Tuesday, September 09, 2008 5:02 PM
>>> To: Openlayers Users List
>>> Subject: [OpenLayers-Users] Highlighting the selected geometry
>>>
>>> Hi,
>>>
>>> is there any examples available which I could use with the following
>>> task? Tried to google, but didn't find any good ones.
>>>
>>> I have two wms-layers in my map. The another one includes some polygons.
>>> In order to get some info out when clicking the polygon, I built a
>>> system which does that. But I would also like to get the selected
>>> polygon to render with a different style, so that it'd be sort of
>>> highlighted. I thought I could copy it into vector layer having
>>> different style. But frankly said, I don't know how to do it. Just
>>> learning OL.
>>>
>>> - mika -
>>> _______________________________________________
>>> Users mailing list
>>> Users at openlayers.org
>>> http://openlayers.org/mailman/listinfo/users
>>>
>>>
>>>
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