[Mapserver-users] Setting the classindex of a shapeObj() has no effect

[Eric Bridger]

Bjoern,
Since I use the same method for drawing points I've run into the same issue.  I think the comments in my Wiki example mention this.  I never figured out exactly why this is so. Perhaps a layers features are drawn without respect to any Class attributes.

The solution  I use is to call $class = $layer->getClass($class_index); # class_index is based on some category
Then set the attrbutes, e.g. $class->{symbol} = $symbol_index;
$class->{size} = 20;
$class->{color} = .... etc.

Finally $pointDraw($map,  $layer, $point ...)

in ADDITION to calling $layer->addFeature($shape) which makes the points queryable.
This seems like something of a hack, i.e. drawing all the points twice.

I don't call $layer->draw()

In your case you may not need to set the class attributes. Perhaps just calling
$layer->getClass(0) or getClass(1) prior to $point->draw() will be enough.

Eric

At 12:36 AM 11/19/2003 +0100, Bjoern Platzen wrote:
>Hi folks,
>
>I'm still messing around with PythonMapScript...
>With a lot of help from the list, I am now able to create queryable 
>Features for a layer. Now I want to show my points with different 
>symbols. In my database-table, Ive got a field for a category. If the 
>category-field contains '1', the point should be drawn with the CLASS 
>0, otherwise with CLASS 1.
>
>Here's the layer-definition in the mapfile:
>LAYER
>  NAME 'baustellen'
>  TYPE POINT
>  STATUS on
>  CLASS
>    Symbol 'bau'
>  END#class
>  CLASS
>    Symbol 'db'
>  END#class
>  TEMPLATE 'rahmen2.html'
>  TOLERANCE 50
>END#LAYER
>END # Map File
>
>Here's the code-snippet, that produces the points:
>for l in r[1]:
>    #r[1] is the resultset[[pointx,pointy,date1,date2,category],[..],..]
>    newPoint = mapscript.pointObj()
>    newPoint.x = l[0]
>    newPoint.y = l[1]
>    newLine = mapscript.lineObj()
>    newLine.add(newPoint)
>    newShape = mapscript.shapeObj(mapscript.MS_SHAPE_POINT)
>    newShape.add(newLine)
>    newShape.index=l[6]
>    if l[4]=='1':#l[4] contains the category
>        newShape.classindex = 0
>    else:
>        newShape.classindex = 1
>    myLayer.addFeature(newShape)
>
>All features are displayed with the symbol defined in CLASS 0.
>
>I thought classindex would be an attribute of the shapeObj() that is 
>read- and writeable.
>
>What will I have to do to display my Points with different 
>symbols/classes??
>
>Thanks in advance for any help!
>
>Bye,
>
>Bjoern
>-- 
>small office solutions
>info at sosnetz.de  -  http://www.sosnetz.de
>
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