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peterstadlerpeterstadler
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add geo module
with some basic functions to work with GeoJSON
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‎testing/geo-tests.xqm

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xquery version "3.1";
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module namespace geot="http://xquery.weber-gesamtausgabe.de/modules/geo-tests";
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declare namespace test="http://exist-db.org/xquery/xqsuite";
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import module namespace geo="http://xquery.weber-gesamtausgabe.de/modules/geo" at "../xquery/geo.xqm";
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declare
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%test:args(
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'{ "type": "Point", "coordinates": [3.5, 2.5] }',
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'[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]'
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)
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%test:assertTrue
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%test:args(
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'{ "type": "Point", "coordinates": [0.0, 5.0] }',
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'[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]'
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)
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%test:assertFalse
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%test:args(
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'{ "type": "Point", "coordinates": [5.0, 0.0] }',
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'[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]'
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)
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%test:assertFalse
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%test:args(
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'{ "type": "Point", "coordinates": [5.0, 2.5] }',
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'[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]'
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)
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%test:assertFalse
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%test:args(
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'{ "type": "Point", "coordinates": [3.5, 7.5] }',
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'[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]'
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)
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%test:assertFalse
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%test:args(
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'{ "type": "Point", "coordinates": [5.0, 7.5] }',
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'[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]'
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)
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%test:assertFalse
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function geot:test-point-in-ring($point as xs:string, $ring as xs:string) as xs:boolean {
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geo:point-in-ring($point => parse-json(), $ring => parse-json())
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};
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declare
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%test:args(
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'{ "type": "Point", "coordinates": [3.5, 2.5] }',
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'[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]'
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)
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%test:assertFalse
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%test:args(
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'{ "type": "Point", "coordinates": [0.0, 5.0] }',
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'[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]'
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)
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%test:assertTrue
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%test:args(
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'{ "type": "Point", "coordinates": [5.0, 0.0] }',
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'[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]'
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)
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%test:assertTrue
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%test:args(
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'{ "type": "Point", "coordinates": [5.0, 2.5] }',
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'[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]'
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)
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%test:assertTrue
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%test:args(
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'{ "type": "Point", "coordinates": [3.5, 7.5] }',
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'[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]'
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)
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%test:assertFalse
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%test:args(
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'{ "type": "Point", "coordinates": [5.0, 7.5] }',
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'[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]'
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)
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%test:assertFalse
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function geot:test-point-on-edge($point as xs:string, $ring as xs:string) as xs:boolean {
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geo:point-on-edge($point => parse-json(), $ring => parse-json())
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};
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declare
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%test:args(
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'{ "type": "Point", "coordinates": [2.5, 2.5] }',
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'{ "type": "Polygon", "coordinates": [[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]] }'
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)
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%test:assertTrue
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%test:args(
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'{ "type": "Point", "coordinates": [2.5, 2.5] }',
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'{ "type": "Polygon", "coordinates": [[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ], [ [1.0, 1.0], [1.0, 4.0], [4.0, 4.0], [4.0, 1.0], [1.0, 1.0] ]]}'
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)
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%test:assertFalse
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%test:args(
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'{ "type": "Point", "coordinates": [4, 4.43832400000014] }',
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'{ "type": "Polygon", "coordinates": [[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ], [ [1.0, 1.0], [1.0, 4.0], [4.0, 4.0], [4.0, 1.0], [1.0, 1.0] ]]}'
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)
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%test:assertTrue
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%test:args(
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'{ "type": "Point", "coordinates": [4, 4.43832400000014] }',
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'{ "type": "Polygon", "coordinates": [[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]] }'
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)
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%test:assertTrue
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%test:args(
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'{ "type": "Point", "coordinates": [0.0, 5.0] }',
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'{ "type": "Polygon", "coordinates": [[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]] }'
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)
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%test:assertTrue
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%test:args(
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'{ "type": "Point", "coordinates": [5.0, 0.0] }',
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'{ "type": "Polygon", "coordinates": [[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]] }'
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)
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%test:assertTrue
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%test:args(
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'{ "type": "Point", "coordinates": [5.0, 2.5] }',
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'{ "type": "Polygon", "coordinates": [[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]] }'
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)
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%test:assertTrue
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%test:args(
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'{ "type": "Point", "coordinates": [3.5, 7.5] }',
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'{ "type": "Polygon", "coordinates": [[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]] }'
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)
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%test:assertFalse
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%test:args(
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'{ "type": "Point", "coordinates": [5.0, 7.5] }',
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'{ "type": "Polygon", "coordinates": [[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]] }'
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)
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%test:assertFalse
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%test:args(
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'{ "type": "Point", "coordinates": [2, 4] }',
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'{ "type": "Polygon", "coordinates": [[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ], [ [1.0, 1.0], [1.0, 4.0], [4.0, 4.0], [4.0, 1.0], [1.0, 1.0] ]]}'
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)
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%test:assertFalse
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%test:args(
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'{ "foo": "bar" }',
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'{ "bli": "baz" }'
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)
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%test:assertError("GeojsonFormatError")
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function geot:test-point-in-polygon($point as xs:string, $polygon as xs:string) as xs:boolean {
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geo:point-in-polygon($point => parse-json(), $polygon => parse-json())
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};

‎testing/run-tests.xql

Lines changed: 3 additions & 1 deletion
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@@ -7,11 +7,13 @@ import module namespace wust="http://xquery.weber-gesamtausgabe.de/modules/wega-
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import module namespace dt="http://xquery.weber-gesamtausgabe.de/modules/date-tests" at "date-tests.xqm";
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import module namespace st="http://xquery.weber-gesamtausgabe.de/modules/str-tests" at "str-tests.xqm";
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import module namespace mt="http://xquery.weber-gesamtausgabe.de/modules/math-tests" at "math-tests.xqm";
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import module namespace geot="http://xquery.weber-gesamtausgabe.de/modules/geo-tests" at "geo-tests.xqm";
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(: the test:suite() function will run all the test-annotated functions in the module whose namespace URI you provide :)
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test:suite((
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util:list-functions("http://xquery.weber-gesamtausgabe.de/modules/date-tests"),
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util:list-functions("http://xquery.weber-gesamtausgabe.de/modules/str-tests"),
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util:list-functions("http://xquery.weber-gesamtausgabe.de/modules/wega-util-shared-tests"),
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util:list-functions("http://xquery.weber-gesamtausgabe.de/modules/math-tests")
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util:list-functions("http://xquery.weber-gesamtausgabe.de/modules/math-tests"),
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util:list-functions("http://xquery.weber-gesamtausgabe.de/modules/geo-tests")
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))

‎xquery/geo.xqm

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xquery version "3.1" encoding "UTF-8";
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(:~
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: XQuery module for geospatial functions
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~:)
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module namespace geo = "http://xquery.weber-gesamtausgabe.de/modules/geo";
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declare namespace array="http://www.w3.org/2005/xpath-functions/array";
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declare variable $geo:GEOJSON_FORMAT_ERROR := QName("http://xquery.weber-gesamtausgabe.de/modules/geo", "GeojsonFormatError");
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(:~
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: Function to check if a point is inside a GeoJSON polygon, considering holes.
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: A point is considered inside the polygon if it is inside the exterior ring
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: and outside all interior rings.
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:
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: @param $point The GeoJSON point to check, e.g. map { "type": "Point", "coordinates": [3.5, 2.5] }
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: @param $polygon The GeoJSON polygon with possible holes, e.g. map { "type": "Polygon", "coordinates": [[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]] }
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: @return xs:boolean True if the point is inside the polygon or on one of the edges, false otherwise.
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:)
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declare function geo:point-in-polygon($point as map(*), $polygon as map(*)) as xs:boolean {
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if(geo:is-valid-point($point) and geo:is-valid-polygon($polygon))
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then
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let $exterior as array(*) := $polygon("coordinates")(1)
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let $interiors as array(*)? :=
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if(array:size($polygon("coordinates")) gt 1)
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then array:tail($polygon("coordinates"))
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else ()
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let $inExterior as xs:boolean := geo:point-in-ring($point, $exterior)
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let $onExteriorEdge as xs:boolean := geo:point-on-edge($point, $exterior)
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let $inAnyInterior as xs:boolean :=
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if(exists($interiors))
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then some $interior in $interiors?* satisfies geo:point-in-ring($point, $interior)
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else false()
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let $onAnyInteriorEdge as xs:boolean :=
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if(exists($interiors))
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then some $interior in $interiors?* satisfies geo:point-on-edge($point, $interior)
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else false()
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return ($inExterior or $onExteriorEdge) and not ($inAnyInterior or $onAnyInteriorEdge)
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else error($geo:GEOJSON_FORMAT_ERROR, 'invalid geojson format')
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};
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(:~
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: Function to check if a point is inside a ring (exterior or interior).
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: Uses the ray-casting algorithm to count the number of intersections of a ray
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: starting from the point.
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:
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: @param $point The GeoJSON point to check, e.g. map { "type": "Point", "coordinates": [3.5, 2.5] }.
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: @param $ring The coordinates of the ring (array of arrays), e.g. [[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]].
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: @return xs:boolean True if the point is inside the ring, false otherwise.
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:)
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declare function geo:point-in-ring($point as map(*), $ring as array(*)) as xs:boolean {
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if(geo:is-valid-point($point) and geo:is-valid-ring($ring))
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then
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let $px as xs:double := $point("coordinates")(1)
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let $py as xs:double := $point("coordinates")(2)
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let $n as xs:integer := array:size($ring)
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let $intersections :=
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for $i in 1 to $n
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let $xi as xs:double := $ring($i)(1)
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let $yi as xs:double := $ring($i)(2)
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(: $j = Index of the previous vertex, which helps in forming edges :)
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let $j as xs:integer :=
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if ($i = 1)
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then $n
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else $i - 1
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let $xj as xs:double := $ring($j)(1)
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let $yj as xs:double := $ring($j)(2)
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return
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if (
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(($yi > $py) != ($yj > $py)) and
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($px < (($xj - $xi) * ($py - $yi) div ($yj - $yi) + $xi))
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)
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then 1
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else 0
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return
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(sum($intersections) mod 2) = 1
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else error($geo:GEOJSON_FORMAT_ERROR, 'invalid geojson format')
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};
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(:~
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: XQuery function that checks whether a point is on the edge of a polygon ring (exterior or interior).
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:
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: @param $point The GeoJSON point to check, e.g. map { "type": "Point", "coordinates": [3.5, 2.5] }.
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: @param $ring The coordinates of the ring (array of arrays), e.g. [[ [0.0, 0.0], [0.0, 5.0], [5.0, 5.0], [5.0, 0.0], [0.0, 0.0] ]].
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: @return True if the point is on one of the edges, false otherwise.
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:)
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declare function geo:point-on-edge($point as map(*), $ring as array(*)) as xs:boolean {
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if(geo:is-valid-point($point) and geo:is-valid-ring($ring))
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then
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let $px as xs:double := $point("coordinates")(1)
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let $py as xs:double := $point("coordinates")(2)
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let $n as xs:integer := array:size($ring)
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let $onEdge :=
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for $i in 1 to $n
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let $xi as xs:double := $ring($i)(1)
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let $yi as xs:double := $ring($i)(2)
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let $j as xs:integer :=
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if ($i = 1)
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then $n
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else $i - 1
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let $xj as xs:double := $ring($j)(1)
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let $yj as xs:double := $ring($j)(2)
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return
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if (
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($px - $xi) * ($yj - $yi) = ($py - $yi) * ($xj - $xi) and
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min(($xi, $xj)) <= $px and
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$px <= max(($xi, $xj)) and
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min(($yi, $yj)) <= $py and
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$py <= max(($yi, $yj))
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)
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then true() else false()
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return some $x in $onEdge satisfies $x
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else error($geo:GEOJSON_FORMAT_ERROR, 'invalid geojson format')
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};
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(:~
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: Function to validate a GeoJSON point.
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:
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: @param $point The GeoJSON point to validate.
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: @return xs:boolean True if the point is valid, false otherwise.
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:)
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declare function geo:is-valid-point($point as map(*)) as xs:boolean {
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($point?type = "Point") and
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exists($point?coordinates) and
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(array:size($point?coordinates) = 2) and
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(every $coord in $point?coordinates?* satisfies $coord instance of xs:double)
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};
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(:~
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: Function to validate a GeoJSON ring (array of coordinates).
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:
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: @param $ring The ring to validate.
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: @return xs:boolean True if the ring is valid, false otherwise.
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:)
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declare function geo:is-valid-ring($ring as array(*)) as xs:boolean {
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array:size($ring) >= 4 and
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$ring(1) = $ring(array:size($ring)) and
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(every $coordinate in $ring?* satisfies (
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array:size($coordinate) = 2 and
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$coordinate(1) instance of xs:double and
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$coordinate(2) instance of xs:double
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))
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};
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(:~
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: Function to validate a GeoJSON polygon.
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:
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: @param $polygon The GeoJSON polygon to validate.
150+
: @return xs:boolean True if the polygon is valid, false otherwise.
151+
:)
152+
declare function geo:is-valid-polygon($polygon as map(*)) as xs:boolean {
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$polygon?type = "Polygon" and
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exists($polygon?coordinates) and
155+
(every $ring in $polygon?coordinates?* satisfies geo:is-valid-ring($ring))
156+
};
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(:~
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: Function to validate GeoJSON input (either Point or Polygon).
160+
:
161+
: @param $geojson The GeoJSON data to validate.
162+
: @return xs:boolean True if the GeoJSON data is valid, false otherwise.
163+
:)
164+
declare function local:is-valid-geojson($geojson as map(*)) as xs:boolean {
165+
($geojson?type = "Point" and geo:is-valid-point($geojson)) or
166+
($geojson?type = "Polygon" and geo:is-valid-polygon($geojson))
167+
};

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