I think you'd better try to call setBaseLayer instead of setVisibility on your layers.
Regards, Pierre On Tue, Oct 7, 2008 at 4:00 PM, Kimball, David (DCR) <[EMAIL PROTECTED]> wrote: > > Hi everyone, I looked into this a bit more and I have a little more info > on what's happening (although I still haven't solved the problem). > > If I create my map with both the layerswitcher control and my HTML > radiobuttons: > > http://maps.massgis.state.ma.us/dcr/forestry11.html > > it becomes clear that the HTML radiobuttons are making layers > visible/invisible, but the layerswitcher control is not updating to > match the chosen layer. > > If I look at the requests being sent to the server using FireBug, it > becomes clear that clicking an HTML radiobutton other than the > default/top choice causes the correct request to be sent (i.e. the > correct Layer with the correct STYLES is requested and the appropriate > image is returned and displayed). Then, when a pan or zoom operation is > performed on the map, an incorrect request is sent, with the > top/original layer (with STYLE of DCR.TOWNS_POLYM_FORESTRY::SUSTCOM_SC > for the main layer) being requested (probably because this is still the > selected layer in the layerswitcher control?). An image is returned > from the server showing the top/original layer instead of the user's > selected layer, and the map does not get refreshed (probably because the > top layer, in the returned image, is set to invisible). > > A few clarifications: > > 1) I want to have radiobuttons that are outside the map so that the user > can't miss seeing them. I've had trouble getting the layerswitcher to > appear where and how I want it when placing it outside the map, and I > think the standard layerswitcher tool inside the map is too "hidden" for > the likely users of this map. > > 2) Clicking a radiobutton needs to change the style that the towns layer > uses to symbolize itself, update the legend graphic, and add a title > above the legend. I'm not sure if the layerswitcher can trigger the > latter two. > > 3) The way I've implemented this is to have one Layer in the map for > each radiobutton. Clicking on a radiobutton makes all layers but that > one invisible. I'm open to different approaches if anyone can think of > one. > > 4) What's going wrong is that the radiobuttons don't properly change the > layer. Clicking on them works at first, but then if you pan or zoom > there is no redraw, because subsequent server requests are asking for > the top/original layer, not the user-selected layer. > > I would greatly appreciate any reply! > > Thanks! > > --David > > > -----Original Message----- > Subject: Toggling layers without LayerSwitcher > > > Hi everyone, > > I'm working on my first OpenLayers map and I'm having a problem with > toggling layer visibility. I want to use an HTML form with radiobuttons > to toggle the layers instead of the LayerSwitcher control. When I > choose a layer other than the first layer in the list, it draws fine > once but if you do any zooming or panning it will not redraw. If you > choose the first layer, it works fine. Here's the map: > > http://maps.massgis.state.ma.us/dcr/forestry09.html > > The function that chooses the new layer is called changeSymbolization > (it's called by the radiobuttons' change event). It loops through the > layers and makes all but one invisible. > > > function changeSymbolization(byField){ > var byFieldSplit = byField.toString().split(','); > lz = map.layers; > for (n=0; n < lz.length; n++) { > lz[n].setVisibility(lz[n].name == > byFieldSplit[0]); > } > document.getElementById("theLegendTitle").innerHTML = > byFieldSplit[1]; > document.getElementById("theLegend").src = > "http://giswebservices.massgis.state.ma.us/geoserver/wms?VERSION=1.1.0&R > EQUEST=GetLegendGraphic&LAYER=massgis:DCR.TOWNS_POLYM_FORESTRY&STYLE=DCR > .TOWNS_POLYM_FORESTRY::" + byFieldSplit[0] + > "&WIDTH=16&HEIGHT=16&FORMAT=image/png"; > > } > > > [this function is called by radiobuttons, for example]: > > > <input type="radio" name="chosenSymbology" > onclick="changeSymbolization(this.value)" value="FSCARS_SC,Towns > symbolized by<br/>National Forest Service<br/>CARS Score:" /> Federal > CARS score<br /> > > > After trying a few approaches, I set it up so there are 17 different > layers added to the map, each of which contains all the background > layers plus the foreground layer (which is symbolized by a different > attribute in each layer). This is done in the init() function. I'm not > sure this is the best way to do it, but when I tried having the > background and foreground layers in separate layers, the foreground > layer would block the background layers by drawing a white background on > the whole map before drawing the foreground layer. > > [Here is what each layer looks like (there are 17 of these, each with a > different name and different Style for one of the layers)]: > > > IMPERV_PCT_Layer = new OpenLayers.Layer.WMS( > "IMPERV_PCT", > "http://giswebservices.massgis.state.ma.us/geoserver/wms";, > { > width: '600', > srs: 'EPSG:26986', > layers: > 'massgis:DCR.TOWNS_POLYM_FORESTRY,massgis:GISDATA.OCEANMASK_POLY,massgis > :GISDATA.NEMASK_POLY,massgis:DCR.TOWNS_POLYM_FORESTRY,massgis:GISDATA.TO > WNS_POLY', > height: '358', > styles: > ',,GISDATA.NEMASK_POLY::Light_Yellow,DCR.TOWNS_POLYM_FORESTRY::IMPERV_PC > T,GISDATA.TOWNS_POLY::Labels_Med', > format: 'image/png' > }, > {singleTile: true, ratio: 1} > ); > IMPERV_PCT_Layer.setVisibility(0); > > > [Here is how they're added to the map]: > > > map.addLayers([SUSTCOM_SC_Layer,FSCARS_SC_Layer,ST_ASST_YN_Layer,MGTPLAN > _YN_Layer,ADV_GRP_YN_Layer,LOC_ORD_YN_Layer,PROSTAF_YN_Layer,TREEINV_YN_ > Layer,TREECITYYN_Layer,OSPLAN_YN_Layer,PDENSQMI00_Layer,BUDGET_P_C_Layer > ,UFORE_YN_Layer,STRATUM_YN_Layer,UCF_INDEX_Layer,CANOPY_COV_Layer,IMPERV > _PCT_Layer]); > > > I tried to find a similar example somewhere, but they seem to use the > layerswitcher control and be really simple (Examples) or be so complex > that I couldn't make heads of tails of them (Gallery). > > Does anyone have a suggestion for how to fix the redrawing problem, or a > better approach to dealing with the layer switching that would solve the > problem? Thank you for your help! > > --David > _______________________________________________ > Users mailing list > [email protected] > http://openlayers.org/mailman/listinfo/users > _______________________________________________ Users mailing list [email protected] http://openlayers.org/mailman/listinfo/users
