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Hi,
I have been trying to style a layer using filter functions if_then_else and greaterEqualThan and have found that greaterEqualThan is behaving very strangely.
To replicate the issue, I have created a simple SLD with the following TextSymbolizer whose labelling can be changed through variable substitution.
<sld:TextSymbolizer>
<sld:Label>
<ogc:Function name="Concatenate">
<ogc:Function name="greaterEqualThan">
<ogc:Function name="env">
<ogc:Literal>myvar</ogc:Literal>
<ogc:Literal>0</ogc:Literal>
</ogc:Function>
<ogc:Literal>0</ogc:Literal>
</ogc:Function>
<ogc:Literal>:</ogc:Literal>
<ogc:Function name="env">
<ogc:Literal>myvar</ogc:Literal>
<ogc:Literal>0</ogc:Literal>
</ogc:Function>
</ogc:Function>
</sld:Label>
<!-- Font, LabelPlacement as appropriate -->
</sld:TextSymbolizer>
I have applied the style to a simple shapefile and checked the labelling with different “myvar” values.
The general finding was
- greaterEqualThan determines 1 and 2 as “>= 0”
- greaterEqualThan determines 0 and 3 to 9 as “< 0”
- Negative numbers are determined as “< 0”
- For numbers larger than 9, the results seem to be depending on the first (leftmost) digit. So
- 10 - 29, 100 - 299 and 1000 - 2999 are determined as “>= 0”
- 30 - 99, 300 - 999 and 3000 - 9999 are determined as “< 0”
- The behaviour was the same with numbers with decimal places.
- With double numbers fed from Postgres instead of variable substitute, the behaviour was the same
- With numbers starting with zero, the behaviour was different
- If the total character length was 2 or 3, the results were true
eg. 00 - 09, 000 - 099 and 0.1 - 0.9 were “>= 0”
- If the length was one or longer than 3, the results were always false
eg. 0, 0000 - 0999 and 0.10 - 0.99 are “< 0”
I have not tried different threadsholds or other siblings (greaterThan, lessThan and lessEqualThan) but I supect either the SLD parser or GeoTools is not evaluating numeric strings appropriately at least for this function.
Kind regards,
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