Hi Andreas, your example convinced me. I think the proposed addition/change might indeed lead to more confusion instead of more clarity/intuitive behaviour.
Thanks for discussing this. Cheers, Marc On 24.08.2010 15:38, Andreas Hocevar wrote: > 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 >>>>> >>>>> >>>>> _______________________________________________ Users mailing list [email protected] http://openlayers.org/mailman/listinfo/users
