OpenLayers v4.6.5 API

Class: GML

ol .format.GML

import GML from 'ol/format/gml';

Feature format for reading and writing data in the GML format version 3.1.1. Currently only supports GML 3.1.1 Simple Features profile.

new ol.format.GML(opt_options)

src/ol/format/gml.js, line 18

Name Type Description

options

Optional configuration object.

Name	Type	Description
`featureNS`	Object.<string, string> \| string \| undefined	Feature namespace. If not defined will be derived from GML. If multiple feature types have been configured which come from different feature namespaces, this will be an object with the keys being the prefixes used in the entries of featureType array. The values of the object will be the feature namespaces themselves. So for instance there might be a featureType item `topp:states` in the `featureType` array and then there will be a key `topp` in the featureNS object with value `http://www.openplans.org/topp`.
`featureType`	Array.<string> \| string \| undefined	Feature type(s) to parse. If multiple feature types need to be configured which come from different feature namespaces, `featureNS` will be an object with the keys being the prefixes used in the entries of featureType array. The values of the object will be the feature namespaces themselves. So for instance there might be a featureType item `topp:states` and then there will be a key named `topp` in the featureNS object with value `http://www.openplans.org/topp`.
`srsName`	string	srsName to use when writing geometries. Required.
`surface`	boolean \| undefined	Write gml:Surface instead of gml:Polygon elements. This also affects the elements in multi-part geometries. Default is `false`.
`curve`	boolean \| undefined	Write gml:Curve instead of gml:LineString elements. This also affects the elements in multi-part geometries. Default is `false`.
`multiCurve`	boolean \| undefined	Write gml:MultiCurve instead of gml:MultiLineString. Since the latter is deprecated in GML 3, the default is `true`.
`multiSurface`	boolean \| undefined	Write gml:multiSurface instead of gml:MultiPolygon. Since the latter is deprecated in GML 3, the default is `true`.
`schemaLocation`	string \| undefined	Optional schemaLocation to use when writing out the GML, this will override the default provided.

Extends

ol.format.GMLBase

Methods

readFeatures(source, opt_options){Array.<ol.Feature>} inherited src/ol/format/gmlbase.js, line 570

Read all features from a GML FeatureCollection.

Name Type Description

source

Document | Node | Object | string

Source.

options

Options.

Name	Type	Description
`dataProjection`	ol.ProjectionLike	Projection of the data we are reading. If not provided, the projection will be derived from the data (where possible) or the `defaultDataProjection` of the format is assigned (where set). If the projection can not be derived from the data and if no `defaultDataProjection` is set for a format, the features will not be reprojected.
`extent`	ol.Extent	Tile extent of the tile being read. This is only used and required for `ol.format.MVT`. Required.
`featureProjection`	ol.ProjectionLike	Projection of the feature geometries created by the format reader. If not provided, features will be returned in the `dataProjection`.

Returns:

Features.

writeFeatures(features, opt_options){string} src/ol/format/gml.js, line 30

Encode an array of features in GML 3.1.1 Simple Features.

Name Type Description

features

Array.<ol.Feature>

Features.

options

Options.

Name	Type	Description
`dataProjection`	ol.ProjectionLike	Projection of the data we are writing. If not provided, the `defaultDataProjection` of the format is assigned (where set). If no `defaultDataProjection` is set for a format, the features will be returned in the `featureProjection`.
`featureProjection`	ol.ProjectionLike	Projection of the feature geometries that will be serialized by the format writer. If not provided, geometries are assumed to be in the `dataProjection` if that is set; in other words, they are not transformed.
`rightHanded`	boolean \| undefined	When writing geometries, follow the right-hand rule for linear ring orientation. This means that polygons will have counter-clockwise exterior rings and clockwise interior rings. By default, coordinates are serialized as they are provided at construction. If `true`, the right-hand rule will be applied. If `false`, the left-hand rule will be applied (clockwise for exterior and counter-clockwise for interior rings). Note that not all formats support this. The GeoJSON format does use this property when writing geometries.
`decimals`	number \| undefined	Maximum number of decimal places for coordinates. Coordinates are stored internally as floats, but floating-point arithmetic can create coordinates with a large number of decimal places, not generally wanted on output. Set a number here to round coordinates. Can also be used to ensure that coordinates read in can be written back out with the same number of decimals. Default is no rounding.

Returns:

Result.

writeFeaturesNode(features, opt_options){Node} src/ol/format/gml.js, line 42

Encode an array of features in the GML 3.1.1 format as an XML node.

Name Type Description

features

Array.<ol.Feature>

Features.

options

Options.

Name	Type	Description
`dataProjection`	ol.ProjectionLike	Projection of the data we are writing. If not provided, the `defaultDataProjection` of the format is assigned (where set). If no `defaultDataProjection` is set for a format, the features will be returned in the `featureProjection`.
`featureProjection`	ol.ProjectionLike	Projection of the feature geometries that will be serialized by the format writer. If not provided, geometries are assumed to be in the `dataProjection` if that is set; in other words, they are not transformed.
`rightHanded`	boolean \| undefined	When writing geometries, follow the right-hand rule for linear ring orientation. This means that polygons will have counter-clockwise exterior rings and clockwise interior rings. By default, coordinates are serialized as they are provided at construction. If `true`, the right-hand rule will be applied. If `false`, the left-hand rule will be applied (clockwise for exterior and counter-clockwise for interior rings). Note that not all formats support this. The GeoJSON format does use this property when writing geometries.
`decimals`	number \| undefined	Maximum number of decimal places for coordinates. Coordinates are stored internally as floats, but floating-point arithmetic can create coordinates with a large number of decimal places, not generally wanted on output. Set a number here to round coordinates. Can also be used to ensure that coordinates read in can be written back out with the same number of decimals. Default is no rounding.

Returns:

Node.