Puneet, I know that you are using php and not Python, but you may want to look at FeatureServer http://featureserver.org/.
David. On Mon, Oct 18, 2010 at 7:50 AM, P Kishor <[email protected]> wrote: > On Mon, Oct 18, 2010 at 7:35 AM, Richard Greenwood > <[email protected]> wrote: >> On Sun, Oct 17, 2010 at 7:17 PM, P Kishor <[email protected]> wrote: >>> I have created a control after the "OpenLayers Measure Example" >>> [http://openlayers.org/dev/examples/measure.html], and all is good. >>> The user can draw a poly in the browser, and measure the area. Now, I >>> want to save the drawn polygon on the server-side, so I can recreate >>> it later. I guess if I could convert the drawn poly to a geojson >>> object, I could save it on the server. Then, at the click of a button, >>> the saved map extent and the drawn feature could be recreated. Any >>> ideas how I could do this? >> >> Puneet, >> >> I send the object to a PHP script on the server and save it into a >> PostGIS database. > > Right, but what is the call for getting the object from the OL client? > I guess I should simplify my question by breaking it up into two parts > -- > > 1. Once I have drawn a poly on the map (using the measure control), > how do I get its geometry that I can then send to the server? All I > need to know here is the appropriate method that will give me the > geometry of the poly I drew. > > 2. What all are the essential params required to reconstruct the state > of a map view in OL? I guess I need to know the layers that are > visible, and the map extent that needs to be saved. In my use case, > since I also want to reconstruct the poly that was drawn, I need that > geometry. The last I can get via #1 above, but how do I get the > "current" map extent and the names of the layers that are currently > visible? Is there a method that can "dump" all the information > required to reconstruct the current state? > >> I don't use GeoJSON or any standard format, but >> probably should. > > What format do you use? > >> Do a POST not a GET as geometries can become quite >> big. And I always do an ST_ISVALID() before inserting it. If you're >> working with polygons it is not uncommon for the user to draw an >> invalid poly and there is nothing to stop that poly from being >> inserted. It is only when you query that invalid poly that the >> problems begin. If you're only working w/ lines and points then it's >> not a worry. >> >> Similarly, I query a PHP script for an object's extent using the >> PostGIS ST_EXTENT() function, and pass that to OpenLayers. ST_EXTENT() >> is an aggregate function, so you can pass a set of records and get the >> bounding box of the whole set, e.g. if you had a bunch of address >> points: >> SELECT ST_EXTENT(wkb_geometry) WHERE zipcode='83014'; >> Would return the bounding box of the whole set of matching points. >> >> In both cases (saving and retrieving) I'm using home grown AJAX calls >> to home grown PHP scripts. I'm sure others will suggest WFS-T which >> has it's strengths, but forces you into WFS. I'm doing everything with >> native MapServer layers. > > Simple is better. I am sticking to WMS with MapServer. For geographic > data I have a mix of shapefiles, images, and PostGIS. For everything > else, I am using SQLite (for now). > > Its all working quite well. > >> >> Regards, >> Rich >> >> >>> -- >>> Puneet Kishor http://www.punkish.org >>> Carbon Model http://carbonmodel.org >>> Charter Member, Open Source Geospatial Foundation http://www.osgeo.org >>> Science Commons Fellow, http://sciencecommons.org/about/whoweare/kishor >>> Nelson Institute, UW-Madison http://www.nelson.wisc.edu >>> ----------------------------------------------------------------------- >>> Assertions are politics; backing up assertions with evidence is science >>> ======================================================================= >>> _______________________________________________ >>> Users mailing list >>> [email protected] >>> http://lists.osgeo.org/mailman/listinfo/openlayers-users >>> >> >> >> >> -- >> Richard Greenwood >> [email protected] >> www.greenwoodmap.com >> > > > > -- > Puneet Kishor http://www.punkish.org > Carbon Model http://carbonmodel.org > Charter Member, Open Source Geospatial Foundation http://www.osgeo.org > Science Commons Fellow, http://sciencecommons.org/about/whoweare/kishor > Nelson Institute, UW-Madison http://www.nelson.wisc.edu > ----------------------------------------------------------------------- > Assertions are politics; backing up assertions with evidence is science > ======================================================================= > _______________________________________________ > Users mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/openlayers-users > _______________________________________________ Users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/openlayers-users
