@geogirafe/lib-geoportal/tools/wfs/wfsparser.js

GeoGirafe is a flexible application to build online geoportals.

import { WFS as OlWFS } from 'ol/format.js';
import GML32 from 'ol/format/GML32.js';
import { CompositeCurveGML3, CompositeCurveGML32 } from './compositecurvegml.js';
/**
 * WFS parser
 *
 * Extends ol.format.WFS to be able to read nested `FeatureCollections` in GML32,
 * which are present in WFS 2.0.0 responses from MapServer, GeoServer and QGIS Server.
 * This does not change behaviour for WFS 1.1.0 and 1.0.0.
 *
 * Can be removed later when the problem linked below is resolved in ol.
 *
 * Code copied and adapted from
 * https://github.com/openlayers/openlayers/issues/12389
 */
export default class WfsParser extends OlWFS {
    constructor(opt_options) {
        const options = {
            gmlFormat: opt_options?.gmlFormat,
            version: opt_options?.version,
            featureNS: opt_options?.featureNS,
            featureType: opt_options?.featureType,
            schemaLocation: opt_options?.schemaLocation
        };
        if (!options.gmlFormat) {
            if (options.version === '2.0.0') {
                options.gmlFormat = new CompositeCurveGML32(options);
            }
            else if (!options.version || options.version === '1.1.0') {
                options.gmlFormat = new CompositeCurveGML3(options);
            }
        }
        super(options);
    }
    readFeatures(source, opt_options) {
        // @ts-expect-error gmlFormat_ is private in super class
        if (this.gmlFormat_ instanceof GML32) {
            return this.readFeaturesGML32(source, opt_options);
        }
        return super.readFeatures(source, opt_options);
    }
    readFeaturesGML32(source, opt_options) {
        let doc;
        if (source instanceof Document) {
            doc = source;
        }
        else if (typeof source === 'string') {
            const domParser = new DOMParser();
            doc = domParser.parseFromString(source, 'application/xml');
        }
        else {
            console.warn('Source for GML3.2 not supported!');
            return [];
        }
        let features;
        if (this.hasNestedFeatureCollectionsGML32(doc)) {
            features = this.readNestedFeatureCollectionsGML32(doc, opt_options);
        }
        else {
            features = super.readFeatures(doc.documentElement, opt_options);
        }
        return features ?? [];
    }
    readNestedFeatureCollectionsGML32(doc, opt_options) {
        let features = [];
        const children = doc.documentElement.children;
        for (const child of children) {
            if (this.isNestedFeatureCollection(child)) {
                const collection = child.children.item(0);
                if (collection?.children?.length) {
                    features = features.concat(super.readFeatures(collection, opt_options));
                }
            }
        }
        return features;
    }
    hasNestedFeatureCollectionsGML32(doc) {
        const children = doc.documentElement.children;
        for (const child of children) {
            if (this.isNestedFeatureCollection(child)) {
                return true;
            }
        }
        return false;
    }
    isNestedFeatureCollection(element) {
        return (element?.localName === 'member' &&
            element.children?.length > 0 &&
            element.children.item(0)?.localName === 'FeatureCollection');
    }
}