[mapserver-users] Label attribute bindings

[Tim Urwin]

Steve,

Thanks for that. Will certainly try it.

Tim

Stephen Woodbridge wrote:
> Tim,
>
> Well in that case you should be able to set CLASSITEM to your position 
> attribute. And then set up a CLASS for each position. This is UGLY in 
> the mapfile, but you should be able to do it now without code changes.
>
> -Steve
>
> Tim Urwin wrote:
>> Hi Steve,
>>
>> Unfortunatly not, it is a single digit 1-9 in an attribute field 
>> which we mapped to the two letter characters used by mapserver for 
>> text position, eg ll cc etc. We would just like to be able to look 
>> this up for each feature rather than apply a blanket approach for the 
>> layer. We would prefer not to edit the data as it changes get updated 
>> on a regular basis (we get updates every 6 to 8 weeks from ordnance 
>> suervey) and the database table has just under 22 and a half million 
>> entries.
>>
>> Thanks
>>
>> Tim
>>
>> Stephen Woodbridge wrote:
>>> Tim,
>>>
>>> When you say "OS has determined the best position for the label", 
>>> what form is this attribute in? Is the x-y position attribute 
>>> columns? or some offset x-y attribute? or what?
>>>
>>> If it is an x-y position that you would rather use that the default 
>>> the_geom geometry position of the feature then it would probably be 
>>> possible to create a view that makes that x-y appear as 
>>> setsrid(makepoint(x_col,y_col),27700) as the_geom in the view and 
>>> then add a record to the geometry_columns table for this view. for 
>>> performance you might want to add this column to the orginal table 
>>> and index it.
>>>
>>> Then you should be able to renter the annotation using the view or 
>>> the alternate column in the table.
>>>
>>> -Steve W
>>>
>>> Tim Urwin wrote:
>>>> Hi all,
>>>>
>>>> This is a questuion about label attribute bindings.
>>>>
>>>> We are about to migrate some of our Ordnance Survey MasterMap data 
>>>> from a propriety system to using mapserver serving the data from a 
>>>> PostGIS database for screen maps. We are currently using Mapserver 
>>>> 5.02 and are very happy with the results we have achieved so far, 
>>>> however, due to only being able to set a single value for the 
>>>> position of a label has caused much of the text to be badly 
>>>> misaligned with the underlying features.
>>>>
>>>> OS has determined the best position for the label and provide this 
>>>> as attribute data for each text label point and we would like to be 
>>>> able to utilise it. Is there anyway to make the position label 
>>>> attribute accept a binding as some of the other values do, e.g. 
>>>> angle which we also use. The problem we have is that no single 
>>>> value works with the data to provide a good map result, therefore 
>>>> we would like to be able to use each feature's value as opposed to 
>>>> a global value.
>>>>
>>>> Any help or insights in how to achieve this will be gratefully 
>>>> received. At the moment our applications access Mapserver via CGI 
>>>> mode directly without the use of mapscript although we could 
>>>> investigate that option.
>>>>
>>>> The following is an example of one of the entries in the mapfile 
>>>> for a label layer.
>>>>
>>>> LAYER
>>>>
>>>>   NAME "Heritage labels"
>>>>
>>>>   METADATA
>>>>      "wms_title" "Heritage labels"
>>>>      "wms_srs"   "EPSG:27700"
>>>>      "wms_extent"   "0.0 0.0 700000.0 1300000.0"
>>>>   END
>>>>
>>>>   STATUS OFF
>>>>
>>>>   CONNECTIONTYPE postgis
>>>>   CONNECTION "user=XXXX password=XXXX dbname=XXXX host=XXXX port=XXXX"
>>>>   DATA '"anchorpoint" from "cartographictext" using unique "fid" 
>>>> using SRID=27700'
>>>>
>>>>   PROCESSING    "CLOSE_CONNECTION=DEFER"
>>>>
>>>>   TYPE Annotation
>>>>
>>>>   LABELITEM 'textstring'
>>>>
>>>>   FILTER ("layer" = '59')
>>>>
>>>>   CLASS
>>>>      NAME 'Antiquity Text (82)'
>>>>         LABEL
>>>>           COLOR     0 0 0
>>>>           OUTLINECOLOR 255 255 255
>>>>           TYPE      TRUETYPE
>>>>           FONT      arial-italic
>>>>           SIZE      8
>>>>           ANGLE  [angle]
>>>>           ANTIALIAS TRUE
>>>>           POSITION  CC
>>>>           PARTIALS  TRUE
>>>>           ENCODING 'UTF-8'
>>>>         END
>>>>   END
>>>>
>>>>   MINSCALEDENOM 100.0
>>>>   MAXSCALEDENOM 5500.0
>>>>
>>>>   PROJECTION
>>>>   "init=epsg:27700"
>>>>   END
>>>> END
>>>>
>>>>
>>>> many thanks
>>>>
>>>> Tim
>>>>
>>>
>>>
>>>
>>
>>
>
>
>

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