heli-agri
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HeliAgri is a high-performance, feature-packed library for creating interactive maps on the web. It can display map tiles, vector data and markers loaded from any source on any web page. OpenLayers has been developed to further the use of geographic infor
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JavaScript
/**
* @module ol/format/Feature
*/
import { abstract } from '../util.js';
import { equivalent as equivalentProjection, get as getProjection, transformExtent, } from '../proj.js';
/**
* @typedef {Object} ReadOptions
* @property {import("../proj.js").ProjectionLike} [dataProjection] Projection of the data we are reading.
* If not provided, the projection will be derived from the data (where possible) or
* the `dataProjection` of the format is assigned (where set). If the projection
* can not be derived from the data and if no `dataProjection` is set for a format,
* the features will not be reprojected.
* @property {import("../extent.js").Extent} [extent] Tile extent in map units of the tile being read.
* This is only required when reading data with tile pixels as geometry units. When configured,
* a `dataProjection` with `TILE_PIXELS` as `units` and the tile's pixel extent as `extent` needs to be
* provided.
* @property {import("../proj.js").ProjectionLike} [featureProjection] Projection of the feature geometries
* created by the format reader. If not provided, features will be returned in the
* `dataProjection`.
*/
/**
* @typedef {Object} WriteOptions
* @property {import("../proj.js").ProjectionLike} [dataProjection] Projection of the data we are writing.
* If not provided, the `dataProjection` of the format is assigned (where set).
* If no `dataProjection` is set for a format, the features will be returned
* in the `featureProjection`.
* @property {import("../proj.js").ProjectionLike} [featureProjection] 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.
* @property {boolean} [rightHanded] 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.
* @property {number} [decimals] 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.
*/
/**
* @typedef {'arraybuffer' | 'json' | 'text' | 'xml'} Type
*/
/**
* @classdesc
* Abstract base class; normally only used for creating subclasses and not
* instantiated in apps.
* Base class for feature formats.
* {@link module:ol/format/Feature~FeatureFormat} subclasses provide the ability to decode and encode
* {@link module:ol/Feature~Feature} objects from a variety of commonly used geospatial
* file formats. See the documentation for each format for more details.
*
* @abstract
* @api
*/
class FeatureFormat {
constructor() {
/**
* @protected
* @type {import("../proj/Projection.js").default|undefined}
*/
this.dataProjection = undefined;
/**
* @protected
* @type {import("../proj/Projection.js").default|undefined}
*/
this.defaultFeatureProjection = undefined;
/**
* A list media types supported by the format in descending order of preference.
* @type {Array<string>}
*/
this.supportedMediaTypes = null;
}
/**
* Adds the data projection to the read options.
* @param {Document|Element|Object|string} source Source.
* @param {ReadOptions} [options] Options.
* @return {ReadOptions|undefined} Options.
* @protected
*/
getReadOptions(source, options) {
if (options) {
let dataProjection = options.dataProjection
? getProjection(options.dataProjection)
: this.readProjection(source);
if (options.extent &&
dataProjection &&
dataProjection.getUnits() === 'tile-pixels') {
dataProjection = getProjection(dataProjection);
dataProjection.setWorldExtent(options.extent);
}
options = {
dataProjection: dataProjection,
featureProjection: options.featureProjection,
};
}
return this.adaptOptions(options);
}
/**
* Sets the `dataProjection` on the options, if no `dataProjection`
* is set.
* @param {WriteOptions|ReadOptions|undefined} options
* Options.
* @protected
* @return {WriteOptions|ReadOptions|undefined}
* Updated options.
*/
adaptOptions(options) {
return Object.assign({
dataProjection: this.dataProjection,
featureProjection: this.defaultFeatureProjection,
}, options);
}
/**
* @abstract
* @return {Type} The format type.
*/
getType() {
return abstract();
}
/**
* Read a single feature from a source.
*
* @abstract
* @param {Document|Element|Object|string} source Source.
* @param {ReadOptions} [options] Read options.
* @return {import("../Feature.js").FeatureLike} Feature.
*/
readFeature(source, options) {
return abstract();
}
/**
* Read all features from a source.
*
* @abstract
* @param {Document|Element|ArrayBuffer|Object|string} source Source.
* @param {ReadOptions} [options] Read options.
* @return {Array<import("../Feature.js").FeatureLike>} Features.
*/
readFeatures(source, options) {
return abstract();
}
/**
* Read a single geometry from a source.
*
* @abstract
* @param {Document|Element|Object|string} source Source.
* @param {ReadOptions} [options] Read options.
* @return {import("../geom/Geometry.js").default} Geometry.
*/
readGeometry(source, options) {
return abstract();
}
/**
* Read the projection from a source.
*
* @abstract
* @param {Document|Element|Object|string} source Source.
* @return {import("../proj/Projection.js").default|undefined} Projection.
*/
readProjection(source) {
return abstract();
}
/**
* Encode a feature in this format.
*
* @abstract
* @param {import("../Feature.js").default} feature Feature.
* @param {WriteOptions} [options] Write options.
* @return {string|ArrayBuffer} Result.
*/
writeFeature(feature, options) {
return abstract();
}
/**
* Encode an array of features in this format.
*
* @abstract
* @param {Array<import("../Feature.js").default>} features Features.
* @param {WriteOptions} [options] Write options.
* @return {string|ArrayBuffer} Result.
*/
writeFeatures(features, options) {
return abstract();
}
/**
* Write a single geometry in this format.
*
* @abstract
* @param {import("../geom/Geometry.js").default} geometry Geometry.
* @param {WriteOptions} [options] Write options.
* @return {string|ArrayBuffer} Result.
*/
writeGeometry(geometry, options) {
return abstract();
}
}
export default FeatureFormat;
/**
* @param {import("../geom/Geometry.js").default} geometry Geometry.
* @param {boolean} write Set to true for writing, false for reading.
* @param {WriteOptions|ReadOptions} [options] Options.
* @return {import("../geom/Geometry.js").default} Transformed geometry.
*/
export function transformGeometryWithOptions(geometry, write, options) {
const featureProjection = options
? getProjection(options.featureProjection)
: null;
const dataProjection = options ? getProjection(options.dataProjection) : null;
let transformed;
if (featureProjection &&
dataProjection &&
!equivalentProjection(featureProjection, dataProjection)) {
transformed = (write ? geometry.clone() : geometry).transform(write ? featureProjection : dataProjection, write ? dataProjection : featureProjection);
}
else {
transformed = geometry;
}
if (write &&
options &&
/** @type {WriteOptions} */ (options).decimals !== undefined) {
const power = Math.pow(10, /** @type {WriteOptions} */ (options).decimals);
// if decimals option on write, round each coordinate appropriately
/**
* @param {Array<number>} coordinates Coordinates.
* @return {Array<number>} Transformed coordinates.
*/
const transform = function (coordinates) {
for (let i = 0, ii = coordinates.length; i < ii; ++i) {
coordinates[i] = Math.round(coordinates[i] * power) / power;
}
return coordinates;
};
if (transformed === geometry) {
transformed = geometry.clone();
}
transformed.applyTransform(transform);
}
return transformed;
}
/**
* @param {import("../extent.js").Extent} extent Extent.
* @param {ReadOptions} [options] Read options.
* @return {import("../extent.js").Extent} Transformed extent.
*/
export function transformExtentWithOptions(extent, options) {
const featureProjection = options
? getProjection(options.featureProjection)
: null;
const dataProjection = options ? getProjection(options.dataProjection) : null;
if (featureProjection &&
dataProjection &&
!equivalentProjection(featureProjection, dataProjection)) {
return transformExtent(extent, dataProjection, featureProjection);
}
return extent;
}