Thursday, November 12, 2009

Data access/connection method











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Inline MapServer Features

Inline features refer to coordinates entered directly into the map file. They aren't a file or database format and don't require any DATA or CONNECTION parameters. Instead they use a FEATURE section to define the coordinates.

Inline features can be used to define points, lines, and polygons as if taken from an external file; this requires direct entry of coordinate pairs in the map file using a particular syntax.



Data access/connection method



This is a native MapServer option that doesn't use any external libraries to support it.





Map file example



Each FEATURE..END section defines a feature.





Points



Multiple points can be defined in a FEATURE section. If multiple points are defined in the same layer, they have the same CLASS settings; for example, for colors and styles.



Coordinates are entered in the units set in the layer's projection. In this case, it assumes the map file projection is using decimal degrees.





LAYER

NAME inline_stops

TYPE POINT

STATUS DEFAULT

FEATURE

POINTS

72.36 33.82

END

TEXT "My House"

END

FEATURE

POINTS

69.43 35.15

71.21 37.95

72.02 38.60

END

TEXT "My Stores"

END

CLASS

COLOR 0 0 250

SYMBOL 'circle'

SIZE 6

END

END










Lines



Lines are simply a list of points strung together, but the layer must be TYPE LINE instead of TYPE POINT.





LAYER

NAME inline_track

TYPE LINE

STATUS DEFAULT

MAXSCALE 10000000

FEATURE

POINTS

72.36 33.82

70.85 34.32

69.43 35.15

70.82 36.08

70.90 37.05

71.21 37.95

END

END

CLASS

COLOR 255 10 0

SYMBOL 'circle'

SIZE 2

END

END










Polygons



Polygons are the same as the line example, just a list of points.



They require the TYPE POLYGON parameter, and the final coordinate pair needs to be the same as the first, making it a closed polygon.

















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