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<< Click to Display Table of Contents >> Navigation: Albion 6 GIS User Guide > Appendix > APPENDIX A: Scripting in Albion GIS > Sample Lua Text Scripts |
The following samples demonstrate how to write scripts in Lua. Such scripts are typically used to create GIS labels.
Format
All of the samples assume that the script is operating on a database record with the following fields and values:
distribution_zone |
original_diameter |
diameter |
material |
code |
|---|---|---|---|---|
983 |
0.200 |
0.150 |
PVC |
HC203 |
Examples
Show 'abc':
return "abc"
abc
Show 12 * 3:
return 12 * 3
36
Show 'abc ' joined to 12 * 3 (this will produce abc36):
return "abc" .. (12 * 3)
abc36
Show 'yes' if original_diameter equals 0.2, otherwise 'no':
if record.original_diameter == 0.2 then return "yes"
else return "no"
end
yes
Show A, B, C on 3 lines:
return "A" .. "\n" .. "B" .. "\n" .. "C"
A
B
C
If diameter is greater than 0.15, then show material, otherwise show 'narrow':
if record.diameter > 0.15 then return record.material
else return "narrow"
end
narrow
If current diameter is greater than original diameter, then show 'expanded', otherwise show nothing:
if record.diameter > record.original_diameter then return "expanded"
else return nil
end
(no text object is generated when you return nil or an otherwise empty result)
Use your own variables as temporary placeholders:
local x = record.material
if record.diameter >= 0.15 then
x = record.material .. '!'
end
x = x .. '\n' .. record.code
return x
PVC!
HC203
Format sin( 45° ) to 4 significant digits:
-- The trigonometric functions take parameters in radians, not degrees
local v = math.sin( math.rad(45) )
return string.format( "%.4g", v )
0.7071
Format log10( 1234 ) to 3 digits after the decimal point:
v = math.log10( 1001 )
return string.format( "%.3f", v )
3.091
Show material -- code:
return record.material .. "--" .. record.code
PVC -- HC203
Show average of original and current diameters:
return (record.original_diameter + record.diameter) / 2.0
0.175
Text with double quotes in it:
return 'this is "quoted"'
this is "quoted"
Text with single quotes in it:
return "this is 'quoted'"
this is 'quoted'