@geogirafe/lib-geoportal/tools/utils/olutils.js

GeoGirafe is a flexible application to build online geoportals.

import { fromCircle } from 'ol/geom/Polygon.js';
import { get as getProjection } from 'ol/proj';
import { getDistance as getSphericalDistance, getArea as getSphericalArea } from 'ol/sphere';
import { unByKey } from 'ol/Observable';
import { LineString } from 'ol/geom';
import GeoConsts from '../geoconsts';
import StateManager from '../state/statemanager';
/**
 * Unsubscribe to all OpenLayer listeners.
 */
export const unByKeyAll = (eventKeys) => {
    eventKeys.forEach((eventKey) => unByKey(eventKey));
};
/**
 * @returns a layer in the map that match the given name (property name).
 */
export const getOlayerByName = (map, layerName) => {
    return map.getAllLayers().find((layer) => layer.get('name') === layerName);
};
/**
 * Clone the properties of the given feature and delete ol properties to keep only the feature "app" properties.
 * Handle map server values served as object and serve them as "simple" values.
 */
export const removeUnwantedOlParams = (feature, keepGeom = false) => {
    const properties = { ...feature.getProperties() };
    delete properties.boundedBy;
    if (!keepGeom) {
        delete properties[feature.getGeometryName()];
    }
    // Handle map server values served as object.
    Object.keys(properties).forEach((key) => {
        const value = properties[key];
        if (typeof value === 'object') {
            if (value['xsi:nil'] === 'true') {
                properties[key] = undefined;
            }
            else if (value['_content_']) {
                properties[key] = value['_content_'];
            }
        }
    });
    return properties;
};
/**
 * @returns A polygon generated from the circle.
 */
export const polygonFromCircle = (geometry) => {
    return fromCircle(geometry, GeoConsts.CIRCLE_TO_POLYGON_SIDES);
};
/**
 * @param coordinates ol Coordinate list
 * @returns the length between coordinates, considering the current map projection (projected or geographic)
 */
export const getDistance = (coordinates) => {
    if (isProjectionInDegrees()) {
        let totalLength = 0;
        coordinates.forEach((coordinate, idx) => {
            if (coordinates[idx + 1]) {
                totalLength += getSphericalDistance(coordinate, coordinates[idx + 1]);
            }
        });
        return totalLength;
    }
    return new LineString(coordinates).getLength();
};
/**
 * @param polygon ol Polygon
 * @returns the area of a polygon, considering the current map projection (projected or geographic)
 */
export const getArea = (polygon) => {
    if (isProjectionInDegrees()) {
        return getSphericalArea(polygon, { projection: getProjection(StateManager.getInstance().state.projection) });
    }
    return polygon.getArea();
};
export const isProjectionInDegrees = () => {
    const projection = getProjection(StateManager.getInstance().state.projection);
    return projection?.getUnits() === 'degrees';
};
export const isCoordinateInDegrees = (coordinate) => {
    return coordinate[0] > -90 && coordinate[0] < 90 && coordinate[1] > -180 && coordinate[1] < 180;
};