Polygon.parse constructor
Polygon.parse(
- String text, {
- TextReaderFormat<
SimpleGeometryContent> format = GeoJSON.geometry, - CoordRefSys? crs,
- Map<
String, dynamic> ? options,
Parses a polygon geometry from text
conforming to format
.
When format
is not given, then the geometry format of GeoJSON is used
as a default.
Use crs
to give hints (like axis order, and whether x and y must
be swapped when read in) about coordinate reference system in text input.
When data itself have CRS information it overrides this value.
Format or decoder implementation specific options can be set by options
.
Examples:
// a polygon (with an exterior ring only) from 2D positions
Polygon.parse(
format: GeoJSON.geometry,
'''
{
"type": "Polygon",
"coordinates": [
[
[10.0,20.0],
[12.5,22.5],
[15.0,25.0],
[11.5,27.5],
[10.0,20.0]
]
]
}
''',
);
Polygon.parse(
format: WKT.geometry,
'POLYGON ((10.0 20.0,12.5 22.5,15.0 25.0,11.5 27.5,10.0 20.0))',
);
// a polygon (with an exterior ring only) from 3D positions
Polygon.parse(
format: GeoJSON.geometry,
'''
{
"type": "Polygon",
"coordinates": [
[
[10.0,20.0,30.0],
[12.5,22.5,32.5],
[15.0,25.0,35.0],
[11.5,27.5,37.5],
[10.0,20.0,30.0]
]
]
}
''',
);
Polygon.parse(
format: WKT.geometry,
'''
POLYGON Z (
(
10.0 20.0 30.0,
12.5 22.5 32.5,
15.0 25.0 35.0,
11.5 27.5 37.5,
10.0 20.0 30.0
)
)
''',
);
// a polygon (with an exterior ring only) from measured 2D positions
Polygon.parse(
format: WKT.geometry,
'''
POLYGON M (
(
10.0 20.0 40.0,
12.5 22.5 42.5,
15.0 25.0 45.0,
11.5 27.5 47.5,
10.0 20.0 40.0
)
)
''',
);
// a polygon (with an exterior ring only) from measured 3D positions
Polygon.parse(
format: GeoJSON.geometry,
'''
{
"type": "Polygon",
"coordinates": [
[
[10.0,20.0,30.0,40.0],
[12.5,22.5,32.5,42.5],
[15.0,25.0,35.0,45.0],
[11.5,27.5,37.5,47.5],
[10.0,20.0,30.0,40.0]
]
]
}
''',
);
Polygon.parse(
format: WKT.geometry,
'''
POLYGON ZM (
(
10.0 20.0 30.0 40.0,
12.5 22.5 32.5 42.5,
15.0 25.0 35.0 45.0,
11.5 27.5 37.5 47.5,
10.0 20.0 30.0 40.0
)
)
''',
);
Implementation
factory Polygon.parse(
String text, {
TextReaderFormat<SimpleGeometryContent> format = GeoJSON.geometry,
CoordRefSys? crs,
Map<String, dynamic>? options,
}) =>
GeometryBuilder.parse<Polygon>(
text,
format: format,
crs: crs,
options: options,
);