PHP Mapscript should only update the parameters specified

[youknowho]

Extra undefined/unwanted parameters are being appended to a map file when using PHP MapScript. The additional information that is added is:

STYLE
    ANGLE 360
    OPACITY 100
    SYMBOL 0
END

As an example, a CLASS that originally looks like:

CLASS
   EXPRESSION ([pixel] >= 155 AND [pixel] < 164)
   COLOR 28 28 28
END

becomes:

CLASS
     EXPRESSION ([pixel] >= 155 AND [pixel] < 164)
     STYLE
       ANGLE 360
       COLOR 28 28 28
       OPACITY 100
       SYMBOL 0
     END
END

after using the following MapScript code to change ONLY the DATA parameter:

<?php

// Grab POST parameters
$mapFile = $_POST['mapFile'];
$layerString = $_POST['layers'];

// Separate layers on comma
$layers = explode(",", $layerString);

// Load MapServer .map file
$map = ms_newMapObj($mapFile);

// Update map file with each layer
for ($i = 0; $i < sizeof($layers); ++$i) {
 $layerPrefix = explode("_", $layers[$i]);
 $layer = $map->getLayerByName($layerPrefix[0]);
 // Change DATA parameter for layer
 $layer->set("data", 'path/to/data/' . $layers[$i]);
}

// Finished editing, save .map file
$map->save($mapFile);
?>

The expected behavior is that PHP MapScript will only update the specified DATA parameter and nothing else.

[youknowho]

Using the same PHP MapScript code originally posted, PHP MapScript is changing more than first noted. The following changes occur:

1. Alter OUTPUTFORMAT configuration (including deleting the FORMATOPTION "INTERLACE=OFF" parameter needed for TileCache)

2. Add UNITS METERS, STYLE ANGLE 360 OPACITY 100 END to each LAYER, as well as changing TRANSPARENCY ALPHA to OPACITY ALPHA for each LAYER in the map.

MAP configuration before script:

 OUTPUTFORMAT
         NAME PNG24
         DRIVER "GD/PNG"
         MIMETYPE "image/png"
         IMAGEMODE RGB
         EXTENSION "png"
         FORMATOPTION "INTERLACE=OFF"
 END

MAP configuration after script:

OUTPUTFORMAT
   NAME "png"
   MIMETYPE "image/png"
   DRIVER "GD/PNG"
   EXTENSION "png"
   IMAGEMODE "PC256"
   TRANSPARENT FALSE
 END

The layer that I am dynamically changing starts as:

LAYER
 NAME "arrow"
 TYPE POLYGON
 PROJECTION
   "init=epsg:4326"
 END
 METADATA
   "wms_title" "arrow"
 END
 DATA shapefiles/arrow
 STATUS ON
 TRANSPARENCY ALPHA
 CLASS
   STYLE
     ANTIALIAS TRUE
     COLOR 255 0 0
     OUTLINECOLOR 0 0 0
   END ## Style
 END ## Class
END ## Layer

and after PHP MapScript runs looks like:

LAYER
   DATA "shapefiles/arrow"
   METADATA
     "wms_title"       "arrow"
   END
   NAME "arrow"
   PROJECTION
     "init=epsg:4326"
   END
   STATUS ON
   OPACITY ALPHA
   TYPE POLYGON
   UNITS METERS
   CLASS
     STYLE
       ANGLE 360
       ANTIALIAS TRUE
       COLOR 255 0 0
       OPACITY 100
       OUTLINECOLOR 0 0 0
       SYMBOL 0
     END
   END
 END

Through a flag, configuration, directive, etc for PHP MapScript, please enable it to ONLY change the parameters supplied in the script, and not alter/add/remove additional map parameters.