layer/layerRec/wmsFC.js

  1. 'use strict';
  3. const basicFC = require('./basicFC.js')();
  5. /**
  6.  * Searches for a layer title defined by a wms.
  7.  * @function getWMSLayerTitle
  8.  * @private
  9.  * @param  {Object} wmsLayer     esri layer object for the wms
  10.  * @param  {String} wmsLayerId   layers id as defined in the wms (i.e. not wmsLayer.id)
  11.  * @return {String}              layer title as defined on the service, '' if no title defined
  12.  */
  13. function getWMSLayerTitle(wmsLayer, wmsLayerId) {
  14.     // TODO move this to ogc.js module?
  16.     let targetEntry = null;
  18.     // crawl esri layerInfos (which is a nested structure),
  19.     // returns sublayer that has matching id or null if not found.
  20.     // written as function to allow recursion
  21.     const crawlSubLayers = (subLayerInfos, wmsLayerId) => {
  23.         // we use .some to allow the search to stop when we find something
  24.         subLayerInfos.some(layerInfo => {
  25.             // wms ids are stored in .name
  26.             if (layerInfo.name === wmsLayerId) {
  27.                 // found it. save it and exit the search
  28.                 targetEntry = layerInfo;
  29.                 return true;
  30.             } else if (layerInfo.subLayers) {
  31.                 // search children. if in children, will exit search, else will continue
  32.                 return crawlSubLayers(layerInfo.subLayers, wmsLayerId);
  33.             } else {
  34.                 // continue search
  35.                 return false;
  36.             }
  37.         });
  39.         return targetEntry;
  40.     };
  42.     // init search on root layerInfos, then process result
  43.     const match = crawlSubLayers(wmsLayer.layerInfos, wmsLayerId);
  44.     if (match && match.title) {
  45.         return match.title;
  46.     } else {
  47.         return ''; // falsy!
  48.     }
  49. }
  51. /**
  52.  * @class WmsFC
  53.  */
  54. class WmsFC extends basicFC.BasicFC {
  56.     /**
  57.      * Download or refresh the internal symbology for the FC.
  58.      *
  59.      * @function loadSymbology
  60.      * @returns {Promise}         resolves when symbology has been downloaded
  61.      */
  62.     loadSymbology () {
  63.         const configLayerEntries =  this._parent.config.layerEntries;
  64.         const gApi = this._parent._apiRef;
  65.         const legendArray = gApi.layer.ogc
  66.             .getLegendUrls(this._parent._layer, configLayerEntries.map(le => {
  67.                 return {
  68.                     id: le.id,
  69.                     styleToURL: le.styleToURL,
  70.                     currentStyle: le.currentStyle
  71.                 }
  72.             }))
  73.             .map((imageUri, idx) => {
  75.                 const symbologyItem = {
  76.                     name: null,
  77.                     svgcode: null
  78.                 };
  80.                 // config specified name || server specified name || config id
  81.                 const name = configLayerEntries[idx].name ||
  82.                     getWMSLayerTitle(this._parent._layer, configLayerEntries[idx].id) ||
  83.                     configLayerEntries[idx].id;
  85.                 gApi.symbology.generateWMSSymbology(name, imageUri).then(data => {
  86.                     symbologyItem.name = data.name;
  87.                     symbologyItem.svgcode = data.svgcode;
  88.                 });
  90.                 return symbologyItem;
  91.             });
  92.         this.symbology = legendArray;
  93.         return Promise.resolve();
  94.     }
  95. }
  97. module.exports = () => ({
  98.     WmsFC
  99. });