kmap-ui/src/components/ol/source/WikiCommons.js

A components of zmap base on vue2.X

/*	Copyright (c) 2016 Jean-Marc VIGLINO, 
  released under the CeCILL-B license (French BSD license)
  (http://www.cecill.info/licences/Licence_CeCILL-B_V1-en.txt).
  
  @classdesc
  ol_source_WikiCommons is a source that load Wikimedia Commons content in a vector layer.
  
  Inherits from:
  <ol.source.Vector>
*/
import ol_ext_inherits from '../util/ext'
import {bbox as ol_loadingstrategy_bbox} from 'ol/loadingstrategy'
import ol_source_Vector from 'ol/source/Vector'
import ol_Feature from 'ol/Feature'
import ol_geom_Point from 'ol/geom/Point'
import {transform as ol_proj_transform, transformExtent as ol_proj_transformExtent} from 'ol/proj'
import ol_ext_Ajax from '../util/Ajax';

/**
* @constructor ol_source_WikiCommons
* @extends {ol_source_Vector}
* @param {olx.source.WikiCommons=} options
*/
var ol_source_WikiCommons = function(opt_options) {
  var options = opt_options || {};

  options.loader = this._loaderFn;
  
  /** Max resolution to load features  */
  this._maxResolution = options.maxResolution || 100;
  
  /** Result language */
  this._lang = options.lang || "fr";

  /** Query limit */
  this._limit = options.limit || 100;
  
  /** Default attribution */
  if (!options.attributions) options.attributions = [ "&copy; <a href='https://commons.wikimedia.org/'>Wikimedia Commons</a>" ];

  // Bbox strategy : reload at each move
    if (!options.strategy) options.strategy = ol_loadingstrategy_bbox;

  ol_source_Vector.call (this, options);
};
ol_ext_inherits(ol_source_WikiCommons, ol_source_Vector);


/** Decode wiki attributes and choose to add feature to the layer
* @param {feature} the feature
* @param {attributes} wiki attributes
* @return {boolean} true: add the feature to the layer
* @API stable
*/
ol_source_WikiCommons.prototype.readFeature = function (feature, attributes){
  feature.set("descriptionurl", attributes.descriptionurl);
  feature.set("url", attributes.url);
  feature.set("title", attributes.title.replace(/^file:|.jpg$/ig,""));
  feature.set("thumbnail", attributes.url.replace(/^(.+wikipedia\/commons)\/([a-zA-Z0-9]\/[a-zA-Z0-9]{2})\/(.+)$/,"$1/thumb/$2/$3/200px-$3"));
  feature.set("user", attributes.user);
  if (attributes.extmetadata && attributes.extmetadata.LicenseShortName) feature.set("copy", attributes.extmetadata.LicenseShortName.value);
  return true;
};


/** Loader function used to load features.
* @private
*/
ol_source_WikiCommons.prototype._loaderFn = function(extent, resolution, projection){
  if (resolution > this._maxResolution) return;
  var self = this;
  var bbox = ol_proj_transformExtent(extent, projection, "EPSG:4326");
  // Commons API: for more info @see https://commons.wikimedia.org/wiki/Commons:API/MediaWiki
  var url = "https://commons.wikimedia.org/w/api.php?action=query&format=json&origin=*&prop=coordinates|imageinfo"
    + "&generator=geosearch&iiprop=timestamp|user|url|extmetadata|metadata|size&iiextmetadatafilter=LicenseShortName"
    + "&ggsbbox=" + bbox[3] + "|" + bbox[0] + "|" + bbox[1] + "|" + bbox[2]
    + "&ggslimit="+this._limit
    + "&iilimit="+(this._limit-1)
    + "&ggsnamespace=6";

  // Ajax request to get the tile
  ol_ext_Ajax.get({
    url: url,
    success: function(data) {
      //console.log(data);
      var features = [];
      var att, pt, feature;
      if (!data.query || !data.query.pages) return;
      for ( var i in data.query.pages){
        att = data.query.pages[i];
        if (att.coordinates && att.coordinates.length ) {
          pt = [att.coordinates[0].lon, att.coordinates[0].lat];
        } else {
          var meta = att.imageinfo[0].metadata;
          if (!meta) {
            //console.log(att);
            continue;
          }
          pt = [];
          var found=0;
          for (var k=0; k<meta.length; k++) {
            if (meta[k].name=="GPSLongitude") {
              pt[0] = meta[k].value;
              found++;
            }
            if (meta[k].name=="GPSLatitude") {
              pt[1] = meta[k].value;
              found++;
            }
          }
          if (found!=2) {
            //console.log(att);
            continue;
          }
        }
        feature = new ol_Feature(new ol_geom_Point(ol_proj_transform (pt,"EPSG:4326",projection)));
        att.imageinfo[0].title = att.title;
        if (self.readFeature(feature, att.imageinfo[0])) {
          features.push(feature);
        }
      }
      self.addFeatures(features);
  }});
};

export default ol_source_WikiCommons