[Mapserver-users] Q: Dynamic Legends

[Jean-Henry Berevoescu]

Yes and no. Actually in your scenario I still will have some unsolved 
issues.
For example: let's say that at a certain scale, all the layers are to be 
shown
so I can have Drives, Places, Streets, Roads, Highways and so on - but on
the actual map in the actual area it happens to be a wasteland with only a
Road in it. In this case what one would expect from a classical map would be
to only see that symbol - the symbol of the Road type of streets. See 
what I mean?
Maybe the Streets example is not the best for the problem we have here.
Say, a vegetation zones map. One can have, say, 25 types of vegetation. 
At a certain
point and at a certain scale, on the map will only be 3 types. No matter how
one will play with layering, this is not exactly a scale-related 
problem, but
data-related problem. "Does the map shows now forest and grassland now? Then
the legend should not present all the possible vegetation types".

Thanks for your answer,
Jean


Martin, Daniel A wrote:

>I do exactly the same thing.  The way I do it, I have two layers
>pointing at the same data.  One has only the highway class, and the
>other has all street types.  But, here's the trick.  Name both layers
>the SAME exact name.  Now, have the range set where the minscale of the
>highway layer is the maxscale of the detailed street layer.
>
>As the user zooms in and out, MapServer will naturally transition from
>highways to detailed streets.  However, the legend will show exactly
>what you are asking for.  And, by naming both layers the same name, the
>status (on/off) will carry over as the user zooms.  If the highway layer
>was on, the street layer will also be on when the user zooms in.
>
>I know it may sound strange, but I promise it works beautifully.
>
>-Dan
>
>  
>
>>-----Original Message-----
>>From: Jean-Henry Berevoescu [mailto:bjh at globexplorer.com] 
>>Sent: Thursday, January 29, 2004 2:51 PM
>>To: Martin, Daniel A
>>Cc: mapserver-users at lists.gis.umn.edu
>>Subject: Re: [Mapserver-users] Q: Dynamic Legends
>>
>>
>>
>>No. I have, for example, one of the layers with a number of classes 
>>(say, streets, with
>>each type of street having its own class). In a certain area, at a 
>>certain scale, one could
>>get, for example, only highways. What I want is to have the legend 
>>showing only the
>>symbols/definitions for what is actually in the map at a 
>>certain moment.
>>
>>Jean
>>
>>
>>Martin, Daniel A wrote:
>>
>>    
>>
>>>Do you mean layers that are on, and within range, but are 
>>>      
>>>
>>not visible 
>>    
>>
>>>because of your current location?  I don't believe that is possible. 
>>>However, the default is to hide layers that are not visible 
>>>      
>>>
>>or have a 
>>    
>>
>>>status of OFF.  However, if you have layers that have a status of 
>>>DEFAULT, then those are going to show no matter what.
>>>
>>>Am I misunderstanding you?
>>>
>>>-Dan
>>>
>>> 
>>>
>>>      
>>>
>>>>-----Original Message-----
>>>>From: mapserver-users-admin at lists.gis.umn.edu
>>>>[mailto:mapserver-users-admin at lists.gis.umn.edu] On Behalf Of 
>>>>Jean-Henry Berevoescu
>>>>Sent: Thursday, January 29, 2004 1:16 PM
>>>>To: mdoggett at coas.oregonstate.edu
>>>>Cc: mapserver-users at lists.gis.umn.edu
>>>>Subject: Re: [Mapserver-users] Q: Dynamic Legends
>>>>
>>>>
>>>>
>>>>I tried that one and all the possible combinations (and their
>>>>sum). Nothing works.
>>>>
>>>>Thanks,
>>>>Jean
>>>>
>>>>
>>>>Matt Doggett wrote:
>>>>
>>>>   
>>>>
>>>>        
>>>>
>>>>>I believe HTML legends will do the trick. In the
>>>>>     
>>>>>
>>>>>          
>>>>>
>>>>legend_template.html
>>>>   
>>>>
>>>>        
>>>>
>>>>>file you could specify [leg_class_html opt_flag=12] for 
>>>>>          
>>>>>
>>example. see
>>    
>>
>>>>>the HTML legend How-To for more details about the opt_flag 
>>>>>          
>>>>>
>>bit mask.
>>    
>>
>>>>>http://mapserver.gis.umn.edu/doc40/html-legend-howto.html
>>>>>
>>>>>MD
>>>>>
>>>>>
>>>>>
>>>>>     
>>>>>
>>>>>          
>>>>>
>>>>>>-----Original Message-----
>>>>>>From: mapserver-users-admin at lists.gis.umn.edu
>>>>>>       
>>>>>>
>>>>>>            
>>>>>>
>>>[mailto:mapserver-users-
>>> 
>>>
>>>      
>>>
>>>>>admin at lists.gis.umn.edu] On Behalf Of Jean-Henry Berevoescu
>>>>>Sent: Wednesday, January 28, 2004 8:12 PM
>>>>>To: mapserver-users at lists.gis.umn.edu
>>>>>Subject: [Mapserver-users] Q: Dynamic Legends
>>>>>
>>>>>
>>>>>Hi,
>>>>>Is there a way to have the legend dynamically show only 
>>>>>          
>>>>>
>>the classes 
>>    
>>
>>>>>of
>>>>>  
>>>>>
>>>>>     
>>>>>
>>>>>          
>>>>>
>>>>a
>>>>
>>>>
>>>>   
>>>>
>>>>        
>>>>
>>>>>layer actually
>>>>>shown in a map (not the whole defined set in the mapfile)?
>>>>>
>>>>>Jean
>>>>>
>>>>>_______________________________________________
>>>>>Mapserver-users mailing list Mapserver-users at lists.gis.umn.edu 
>>>>>http://lists.gis.umn.edu/mailman/listinfo/mapserver-users
>>>>>  
>>>>>
>>>>>     
>>>>>
>>>>>          
>>>>>
>>>>   
>>>>
>>>>        
>>>>
>>>_______________________________________________
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>>>
>>> 
>>>
>>>      
>>>
>
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