[mapserver-users] HTML Legend with Status Checking...

[Mike Smith]

Gladly.  Here is my legend code:

[leg_group_html]
  <tr>
        <td colspan=3 bgcolor=#cccccc><b>[leg_group_name]</b></td>
  </tr>
[/leg_group_html]

[leg_layer_html]
[/leg_layer_html]

[leg_class_html]
  <tr>
        <td width=15>&nbsp;</td>
        <td>
          <img src="[leg_icon width=15 height=15]" width=15 height=15>
        </td>
        <td>
          [leg_class_name]
        </td>
  </tr>
[/leg_class_html]


However, it does not work as you say (and as the documentation on the 
web page says!).  Layers that are "off" do not show up (that's as 
expected and what I want), that's fine, but layers that are out of SCALE 
DO show up, and that's not as expected and that's not as the 
documentation states and that's NOT what I want.  For example, I have a 
layer called Ethiopia_Rivers...here's what it looks like:

LAYER
  NAME "Ethiopia_Rivers"
  TYPE LINE
  STATUS off
  GROUP Ethiopia
  DATA "ethiopia_rivers"
  HEADER 'ethiopia_rivers.shp_header.html'
      CLASS
        MAXSCALE 8710165
        Name 'Ethiopia Rivers'
        COLOR 102 204 255
        TEMPLATE ethiopia_rivers.shp_query.html
     END  # CLASS
END  # LAYER

Now, when I'm viewing my map at full extent, my scale factor is 1: 
20136789, therefore if I click on the Ethiopia_Rivers layer at that zoom 
level, nothing shows up in the map.  This is the exact behavior that I 
would expect...I'm out of scale for that layer, so it doesn't show up in 
the map until I zoom in.  The PROBLEM, however, is that the "Ethiopia 
Rivers" icon and label pop up in my legend...this is counter-intuitive, 
contrary to the documented behavior of Mapserver, and just flat-out 
frustrating!  If the layer is not showing up in my map (because it's out 
of scale), then it should NOT be in my legend either.  Grrrr!!!  Pardon 
me for sounding bitter...I'm not lashing out at you, I'm very grateful 
for your help, I'm just frustrated at Mapserver.

Thanks!

Martin, Daniel wrote:

>Perhaps I misunderstood.  By default (no opt_flag set) layers that are out
>of scale and layers that have a STATUS off will not show in an HTML legend.
>
>
>A legend exactly like this should do exactly what it sounds like you want:
>
>[leg_class_html]
><TR>
>  <TD>
>   <img src="[leg_icon]" border=0>
>  </TD>
>  <TD>	 
>    <font face="arial" size=2>[leg_class_name]</font>
>  </TD>
></TR>
>[/leg_class_html]
>
>I'm not sure why you are having trouble getting the default action.  Perhaps
>you could provide your current legend.
>
>-Dan
>
>-----Original Message-----
>From: Mike Smith [mailto:nospam at cnrit.tamu.edu]
>Sent: Tuesday, October 01, 2002 10:59 AM
>To: Martin, Daniel
>Cc: mapserver-users at lists.gis.umn.edu
>Subject: Re: [mapserver-users] HTML Legend with Status Checking...
>
>
>Thank you, but this didn't change a thing.  Actually, let me correct 
>that...it had a negative effect because now all my layers show up too, 
>even if they are not displayed in the map.  I want only active layers to 
>show in the legend and I want only IN-SCALE class symbols to show up in 
>the legend, I don't want 4 symbols to show up in the legend for every 
>layer that I have which has scale-specific classes...I just don't guess 
>I can do that without converting everything over to Mapscript.  X-(
>
>Any other ideas?
>
>Martin, Daniel wrote:
>
>>You probably want a bit mask of 2 in your opt_flag.  Layers with STATUS off
>>still show, but layers out of scale don't show.  
>>
>>[leg_layer_html opt_flag=2]
>>
>>
>>Per http://mapserver.gis.umn.edu/doc36/html-legend-howto.html :
>>
>>1: If set, show layer even if out of scale (default: hide layers out of
>>scale). 
>>
>>2: If set, show layer even if status is OFF (default: hide layers with
>>STATUS OFF). 
>>
>>4: If set, show layer even if type is QUERY (default: hide layers of TYPE
>>QUERY) 
>>
>>8: If set, show layer even if type is ANNOTATION (default: hide layers of
>>TYPE ANNOTATION) 
>>
>>
>>In my experience, opt_flag=2 is the most intuitive.
>>
>>-Dan
>>
>>
>>
>>-----Original Message-----
>>From: Mike Smith [mailto:nospam at cnrit.tamu.edu]
>>Sent: Monday, September 30, 2002 5:06 PM
>>To: mapserver-users at lists.gis.umn.edu
>>Subject: [mapserver-users] HTML Legend with Status Checking...
>>
>>
>>Hello,
>>
>>   I've seen how you can make legends using PHP Mapscript that check to 
>>see whether a layer or class is in scale before displaying it in the 
>>legend, but no mention of how to do this if I'm not using Mapscript.  I 
>>have sub-classed many of my layers so that symbols show up in different 
>>sizes depending on how far zoomed in you are.  In other words, I'm using 
>>"MINSCALE" and "MAXSCALE" in my classes, but all of my classes show up 
>>in the legend and that's really annoying!  I want ONLY the in-scale 
>>symbol to show up in the legend as it does in the map...any tips on how 
>>to do this without Mapscript?  I see the "if" conditional statements in 
>>the HTML Legend How-to, but there's no status of "SCALE" to check with 
>>those statements... if I could put an if statement in my legend template 
>>that checked whether or not a class or layer was in scale, then I'd be 
>>in business...any way to do this?
>>
>>Thanks!
>>
>>
>
>
>

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