On Aug 24, 2010, at 15:15 , Marc Jansen wrote: > Hi Andreas, > > first of all, sorry for cross-posting in the past. I thought it was > useful in this case. > > I'd disagree about the not handling of the layeradd/layerremove event > for the Permalink-control -- but can easily live without this addition > to OpenLayers :-) > > Your suggestions of alternative ways of handling application "state" are > valid and often better suited, yet I think the addition of two > additional listeners to the control would be very intuitive.
This is where I have to disagree. Let's say you have a map with two pre-configured layers. Now user A, who uses the Permalink control as is, adds a layer, resulting in a permalink with "&layers=BT". User B has the same map, adds a completely different layer, but uses your add/removelayer aware Permalink control, resulting in a permalink with "&layers=BTT". Now the interesting part comes when both users send this permalink to someone who opens the permalink. That person will see exactly the same layers with both permalinks - because the map will load only the two pre-configured layers. This is why I wouldn't consider adding add/removelayer handlers to the Permalink control useful or intuitive at all. Regards, Andreas. > > Best regards, > > Marc > > > > On 24.08.2010 14:49, Andreas Hocevar wrote: >> Hi, >> >> first of all, please don't cross-post dev and users. >> >> I am not sure if a permalink as provided by OpenLayers is what you really >> want for applications where the user can add or remove layers. The permalink >> only stores the visible/invisible state of the available layers in their >> order. It does not know anything about what these layers are. So a permalink >> will look exactly the same for any map with the same extent with let's say 3 >> layers that are all visible. >> >> If you want to store information on what layers are actually configured, you >> should look into Format.WMC, Format.OWS or solutions like the OpenGeo >> Suite's GeoExplorer (http://suite.opengeo.org/geoexplorer), which stores >> layer configurations in a database and provides a permalink with a map id. >> >> Regards, >> Andreas. >> >> On Aug 24, 2010, at 14:31 , Marc Jansen wrote: >> >> >>> Hi Slawomir, >>> >>> I'd consider this a bug with a (on first sight) reasonable easy fix: >>> >>> In the Permalinks draw-method: >>> >>> this.map.events.on({ >>> 'moveend': this.updateLink, >>> 'changelayer': this.updateLink, >>> 'changebaselayer': this.updateLink, >>> 'addlayer': this.updateLink, >>> 'removelayer': this.updateLink, >>> scope: this >>> }); >>> >>> Or one could think of triggering a changelayer event when a layer has >>> been added/removed in Map.js. >>> >>> I am unsure which design is better, so I'd suggest opening up a ticket >>> (I cc'ed the developer list so the core developers notice this discussion). >>> >>> Regards, >>> Marc >>> >>> >>> >>> >>> On 24.08.2010 13:53, Slawomir Messner wrote: >>> >>>> Hello, >>>> Does anyone know why Permalink doesn't listen to addlayer/removelayer? >>>> Every time I add a new layer I have to change a property(i.e. >>>> visibility) to refresh the link. It's a bug or a feature? >>>> Regards, >>>> Slawomir >>>> >>>> >>> _______________________________________________ >>> Dev mailing list >>> d...@openlayers.org >>> http://openlayers.org/mailman/listinfo/dev >>> >> > > > -- > > ................................................................. > Karten im (Inter|Intra)net? > > OpenLayers - Webentwicklung mit dynamischen Karten und Geodaten > von M. Jansen und T. Adams, OpenSourcePress, München. > > ISBN: 978-3-937514-92-5 > URL: http://openlayers-buch.de > ................................................................. > > > Dipl.-Geogr. Marc Jansen > - Anwendungsentwickler - > > terrestris GmbH& Co. KG > Irmintrudisstraße 17 > 53111 Bonn > > Tel: ++49 (0)228 / 96 28 99 -53 > Fax: ++49 (0)228 / 96 28 99 -57 > > Email: jan...@terrestris.de > Web: http://www.terrestris.de > > Amtsgericht Bonn, HRA 6835 > Komplementärin: terrestris Verwaltungsgesellschaft mbH > vertreten durch: Hinrich Paulsen, Till Adams > > > _______________________________________________ > Users mailing list > Users@openlayers.org > http://openlayers.org/mailman/listinfo/users -- Andreas Hocevar OpenGeo - http://opengeo.org/ Expert service straight from the developers. _______________________________________________ Users mailing list Users@openlayers.org http://openlayers.org/mailman/listinfo/users
