kmap-ui/src/components/ol/format/GeoRSS.js

A components of zmap base on vue2.X

/*	Copyright (c) 2019 Jean-Marc VIGLINO, 
  released under the CeCILL-B license (French BSD license)
  (http://www.cecill.info/licences/Licence_CeCILL-B_V1-en.txt).
*/
import ol_ext_inherits from '../util/ext'
import ol_Object from 'ol/Object'
import ol_Feature from 'ol/Feature'
import ol_geom_Point from 'ol/geom/Point'
import ol_geom_Polygon from 'ol/geom/Polygon'

/** Feature format for reading data in the GeoRSS format.
 * @constructor ol_fromat_GeoRSS
 * @extends {ol_Object}
 * @param {*} options options.
 *  @param {ol.ProjectionLike} options.dataProjection Projection of the data we are reading. If not provided `EPSG:4326`
 *  @param {ol.ProjectionLike} options.featureProjection Projection of the feature geometries created by the format reader. If not provided, features will be returned in the dataProjection.
 */
var ol_format_GeoRSS = function(options) {
  options = options || {};
  ol_Object.call (this, options);
};
ol_ext_inherits(ol_format_GeoRSS, ol_Object);

/**
 * Read a feature.  Only works for a single feature. Use `readFeatures` to
 * read a feature collection.
 *
 * @param {Node|string} source Source.
 * @param {*} options Read options.
 *  @param {ol.ProjectionLike} options.dataProjection Projection of the data we are reading. If not provided `EPSG:4326`
 *  @param {ol.ProjectionLike} options.featureProjection Projection of the feature geometries created by the format reader. If not provided, features will be returned in the dataProjection.
 * @return {ol.Feature} Feature or null if no feature read
 * @api
 */
ol_format_GeoRSS.prototype.readFeature = function(source, options) {
  options = options || {};
  var att, atts = source.children;
  var f = new ol_Feature();
  // Get attributes
  for (var j=0; att = atts[j]; j++) {
    f.set(att.tagName, att.innerHTML);
  }
  var temp, g, coord=[];
  // Get geometry
  if (f.get('geo:long')) {
    // LonLat
    g = new ol_geom_Point([parseFloat(f.get('geo:long')), parseFloat(f.get('geo:lat'))]);
    f.unset('geo:long');
    f.unset('geo:lat');
  } else if (f.get('georss:point')) {
    // Point
    coord = f.get('georss:point').trim().split(' ');
    g = new ol_geom_Point([parseFloat(coord[1]), parseFloat(coord[0])]);
    f.unset('georss:point');
  } else if (f.get('georss:polygon')) {
    // Polygon
    temp = f.get('georss:polygon').trim().split(' ');
    for (var i=0; i<temp.length; i += 2) {
      coord.push([parseFloat(temp[i+1]), parseFloat(temp[i])]) 
    }
    g = new ol_geom_Polygon([coord]);
    f.unset('georss:polygon');
  } else if (f.get('georss:where')) {
    // GML
    console.warn('[GeoRSS] GML format not implemented')
    f.unset('georss:where');
    return null;
  } else {
    console.warn('[GeoRSS] unknown geometry')
    return null;
  }
  if (options.featureProjection || this.get('featureProjection')) {
    g.transform (options.dataProjection || this.get('dataProjection') || 'EPSG:4326', options.featureProjection || this.get('featureProjection'));
  }
  f.setGeometry(g);
  return f;
};

/**
 * Read all features.  Works with both a single feature and a feature
 * collection.
 *
 * @param {Document|Node|string} source Source.
 * @param {*} options Read options.
 *  @param {ol.ProjectionLike} options.dataProjection Projection of the data we are reading. If not provided `EPSG:4326`
 *  @param {ol.ProjectionLike} options.featureProjection Projection of the feature geometries created by the format reader. If not provided, features will be returned in the dataProjection.
 * @return {Array<ol.Feature>} Features.
 * @api
 */
ol_format_GeoRSS.prototype.readFeatures = function(source, options) {
  var items;
  if (typeof(source)==='string') {
    var parser = new DOMParser();
    var xmlDoc = parser.parseFromString(source,"text/xml");
    items = xmlDoc.getElementsByTagName(this.getDocumentItemsTagName(xmlDoc));
  } else if (source instanceof Document) {
    items = source.getElementsByTagName(this.getDocumentItemsTagName(source));
  } else if (source instanceof Node) {
    items = source;
  } else {
    return [];
  }

  var features = []
  for (var i=0, item; item = items[i]; i++) {
    var f = this.readFeature(item, options);
    if (f) features.push(f);
  }

  return features;
};

/**
 * Get the tag name for the items in the XML Document depending if we are
 * dealing with an atom base document or not.
 * @param {Document} xmlDoc document to extract the tag name for the items
 * @return {string} tag name
 * @private
 */
ol_format_GeoRSS.prototype.getDocumentItemsTagName = function(xmlDoc) {
  switch (xmlDoc.documentElement.tagName) {
    case 'feed':
      return 'entry';
    default:
      return 'item';
  }
}

export default ol_format_GeoRSS