Make CesiumGeohash compatible with new methods +

Other minor fixes and improvements:
- Add configurable collection-wide min and max precision values in Geohashes (set max to 9 rather than 6)
- Always validate precisions and bounds in methods that use them in Geohashes collection
- Account for bounding boxes that cross the antimeridian or have north < south when calculating area
- Fix issue where the search results remained in "loading" state when the search was cancelled (e.g. the request URL didn't change, happens when the Cesium camera view has not changed sufficiently)
- Decrease limit of number of geohashes in spatial filter to respect Solr's boolean clauses limit
- Fix issue where pager was hidden when there were 25-50 results
- Remove old CesiumGeohashes view
- Remove unused methods from CesiumGeohash model & Geohashes collection

Issues: #2119, #1720

src/js/models/connectors/Filters-Map.js

@@ -33,6 +33,9 @@ define(["backbone", "collections/Filters", "models/maps/Map"], function (
        * @property {boolean} isConnected Whether the connector is currently
        * listening to the Map model for changes. Set automatically when the
        * connector is started or stopped.
+       * @property {function} onMoveEnd A function to call when the map is
+       * finished moving. This function will be called with the connector as
+       * 'this'.
        * @since x.x.x
        */
       defaults: function () {
@@ -41,6 +44,7 @@ define(["backbone", "collections/Filters", "models/maps/Map"], function (
           spatialFilters: [],
           map: new Map(),
           isConnected: false,
+          onMoveEnd: this.updateSpatialFilters,
         };
       },
 
@@ -187,7 +191,12 @@ define(["backbone", "collections/Filters", "models/maps/Map"], function (
           this.listenTo(map, "moveStart", function () {
             this.get("filters").trigger("changing");
           });
-          this.listenTo(map, "moveEnd", this.updateSpatialFilters);
+          this.listenTo(map, "moveEnd", function () {
+            const moveEndFunc = this.get("onMoveEnd");
+            if (typeof moveEndFunc === "function") {
+              moveEndFunc.call(this);
+            }
+          });
           this.set("isConnected", true);
         } catch (e) {
           console.log("Error starting Filter-Map listeners: ", e);

src/js/models/connectors/Filters-Search.js

@@ -144,6 +144,9 @@ define([
         // do anything. This function may have been triggered by a change event
         // on a filter that doesn't affect the query at all
         if (!searchResults.hasChanged()) {
+          // Trigger a reset event to indicate the search is complete (e.g. for
+          // the UI)
+          searchResults.trigger("reset");
           return;
         }
 

src/js/models/connectors/Map-Search-Filters.js

@@ -214,6 +214,7 @@ define([
        * so that they work together.
        */
       connect: function () {
+        this.coordinateMoveEndSearch();
         this.getConnectors().forEach((connector) => connector.connect());
       },
 
@@ -227,6 +228,54 @@ define([
         this.get("filtersMapConnector").disconnect(resetSpatialFilter);
         this.get("filtersSearchConnector").disconnect();
         this.get("mapSearchConnector").disconnect();
+        this.resetMoveEndSearch();
+      },
+
+      /**
+       * Coordinate behaviour between the two map related sub-connectors when
+       * the map extent changes. This is necessary to reduce the number of
+       * search queries. We keep the moveEnd behaviour within the sub-connectors
+       * so that each sub-connector still functions independently from this
+       * coordinating connector.
+       */
+      coordinateMoveEndSearch: function () {
+        // Undo any previous coordination, if any
+        this.resetMoveEndSearch();
+
+        const map = this.get("map");
+        const mapConnectors = this.getMapConnectors();
+
+        // Stop the sub-connectors from doing anything on moveEnd by setting
+        // their method they call on moveEnd to null
+        mapConnectors.forEach((connector) => {
+          connector.set("onMoveEnd", null);
+        });
+
+        // Set the single moveEnd listener here, and run the default moveEnd
+        // behaviour for each sub-connector. This effectively triggers only one
+        // search per moveEnd.
+        this.listenTo(map, "moveEnd", function () {
+          mapConnectors.forEach((connector) => {
+            const moveEndFunc = connector.defaults().onMoveEnd;
+            if (typeof moveEndFunc === "function") {
+              moveEndFunc.call(connector);
+            }
+          });
+        });
+      },
+
+      /**
+       * Undo the coordination of the two map related sub-connectors when the
+       * map extent changes. Reset the moveEnd behaviour of the sub-connectors
+       * to their defaults.
+       * @see coordinateMoveEndSearch
+       */
+      resetMoveEndSearch: function () {
+        this.stopListening(this.get("map"), "moveEnd");
+        const mapConnectors = this.getMapConnectors();
+        mapConnectors.forEach((connector) => {
+          connector.set("onMoveEnd", connector.defaults().onMoveEnd);
+        });
       },
 
       /**
@@ -238,7 +287,14 @@ define([
        * remove any spatial constraints from the search.
        */
       disconnectFiltersMap: function (resetSpatialFilter = false) {
-        this.get("filtersMapConnector").disconnect(resetSpatialFilter);
+        const [mapSearch, filtersMap] = this.getMapConnectors();
+
+        if (mapSearch.get("isConnected")) {
+          this.resetMoveEndSearch();
+          mapSearch.set("onMoveEnd", mapSearch.defaults().onMoveEnd);
+        }
+
+        filtersMap.disconnect(resetSpatialFilter);
       },
 
       /**
@@ -247,7 +303,12 @@ define([
        * the extent of the map view.
        */
       connectFiltersMap: function () {
-        this.get("filtersMapConnector").connect();
+        const [mapSearch, filtersMap] = this.getMapConnectors();
+
+        if (mapSearch.get("isConnected")) {
+          this.coordinateMoveEndSearch();
+        }
+        filtersMap.connect();
       },
 
       /**
@@ -265,7 +326,7 @@ define([
        */
       removeSpatialFilter: function () {
         this.get("filtersMapConnector").removeSpatialFilter();
-      }
+      },
     }
   );
 });

src/js/models/connectors/Map-Search.js

@@ -22,11 +22,15 @@ define([
        * @type {object}
        * @property {SolrResults} searchResults
        * @property {Map} map
+       * @property {function} onMoveEnd A function to call when the map is
+       * finished moving. This function will be called with the connector as
+       * 'this'.
        */
       defaults: function () {
         return {
           searchResults: null,
           map: null,
+          onMoveEnd: this.onMoveEnd
         };
       },
 
@@ -166,9 +170,10 @@ define([
         // layer again and update the search results (thereby updating the
         // facet counts on the GeoHash layer)
         this.listenTo(map, "moveEnd", function () {
-          this.showGeoHashLayer();
-          this.updateFacet();
-          searchResults.trigger("reset");
+          const moveEndFunc = this.get("onMoveEnd");
+          if (typeof moveEndFunc === "function") {
+            moveEndFunc.call(this);
+          }
         });
 
         // When a new search is being performed, hide the GeoHash layer to
@@ -181,6 +186,18 @@ define([
         this.set("isConnected", true);
       },
 
+      /**
+       * Functions to perform when the map has finished moving. This is separated into its own method
+       * so that external models can manipulate the behavior of this function.
+       * See {@link MapSearchFiltersConnector#onMoveEnd}
+       */
+      onMoveEnd: function () {
+        const searchResults = this.get("searchResults");
+        const map = this.get("map");
+        this.showGeoHashLayer();
+        this.updateFacet();
+      },
+
       /**
        * Make the geoHashLayer invisible.
        * @fires CesiumGeohash#change:visible

src/js/models/filters/SpatialFilter.js

@@ -50,7 +50,9 @@ define([
           operator: "OR",
           fieldsOperator: "OR",
           matchSubstring: false,
-          maxGeohashValues: 100,
+          // 1024 is the default limit in Solr for boolean clauses, limit even
+          // more to allow for other filters
+          maxGeohashValues: 900,
         });
       },
 
@@ -125,6 +127,20 @@ define([
         };
       },
 
+      /**
+       * Returns true if the bounds set on the filter covers the entire earth
+       * @returns {boolean}
+       */
+      coversEarth: function () {
+        const bounds = this.getBounds();
+        return (
+          bounds.north === 90 &&
+          bounds.south === -90 &&
+          bounds.east === 180 &&
+          bounds.west === -180
+        );
+      },
+
       /**
        * Given the current coordinates and height set on the model, update the
        * fields and values to match the geohashes that cover the area. This will
@@ -136,8 +152,17 @@ define([
       updateFilterFromExtent: function () {
         try {
           this.validateCoordinates();
-          let geohashes = new Geohashes();
-          geohashes.addGeohashesByBounds(this.getBounds(), true, 5000, true);
+
+          // If the bounds are global there is no spatial constraint
+          if (this.coversEarth()) {
+            this.set({ fields: [], values: [] });
+            return;
+          }
+
+          const geohashes = new Geohashes();
+          const bounds = this.getBounds();
+          const limit = this.get("maxGeohashValues");
+          geohashes.addGeohashesByBounds(bounds, true, limit, true);
           this.set({
             fields: this.precisionsToFields(geohashes.getPrecisions()),
             values: geohashes.getAllHashStrings(),
@@ -192,10 +217,10 @@ define([
             return "";
           }
 
-          // Merge into the minimal num. of geohashes to reduce query size
           // TODO: we may still want this option for when spatial filters are
           // built other than with the current view extent from the map.
           // geohashes = geohashes.consolidate();
+
           const precisions = geohashes.getPrecisions();
 
           // Just use a regular Filter if there is only one level of geohash

src/js/models/maps/assets/CesiumGeohash.js

@@ -91,7 +91,7 @@ define([
             color: "#f3e227",
           }),
           showLabels: true,
-          maxGeoHashes: 1000,
+          maxGeoHashes: 4000,
         });
       },
 
@@ -151,13 +151,11 @@ define([
        * @returns {number} The precision level.
        */
       getPrecision: function () {
-        try {
-          const height = this.get("mapModel").get("currentViewExtent").height;
-          return this.get("geohashes").heightToPrecision(height);
-        } catch (e) {
-          const precisions = this.get("geohashes").getPrecisions();
-          return Math.min(...precisions);
-        }
+        const limit = this.get("maxGeoHashes");
+        const geohashes = this.get("geohashes")
+        const bounds = this.get("mapModel").get("currentViewExtent");
+        const area = geohashes.getBoundingBoxArea(bounds);
+        return this.get("geohashes").getMaxPrecision(area, limit);
       },
 
       /**
@@ -210,29 +208,6 @@ define([
         if (limitToExtent) {
           geohashes = this.getGeohashesForExtent();
         }
-        const limit = this.get("maxGeoHashes");
-        if(typeof limit === 'number' && geohashes.length > limit) {
-          geohashes = this.reduceGeohashes(geohashes, limit);
-        }
-        return geohashes;
-      },
-
-      /**
-       * Reduce the number of geohashes to no more than the specified number.
-       * @param {Geohashes} geohashes The geohashes to reduce.
-       * @param {number} limitToNum The maximum number of geohashes to return.
-       * @returns {Geohashes} The reduced geohashes.
-       */
-      reduceGeohashes: function (geohashes, limitToNum = 1000) {
-        // For now assume that we will want to summarize the combined property
-        // of interest by summing the values.
-        const propertySummaries = {};
-        propertySummaries[this.getPropertyOfInterest()] = function (vals) {
-          return vals.reduce((a, b) => a + b, 0);
-        }
-        while (geohashes.length > limitToNum) {
-          geohashes = geohashes.clone().reducePrecision(1, propertySummaries);
-        }
         return geohashes;
       },
 
@@ -296,12 +271,8 @@ define([
           model.set("cesiumOptions", cesiumOptions);
           // Create the model like a regular GeoJSON data source
           CesiumVectorData.prototype.createCesiumModel.call(this, recreate);
-        } catch (error) {
-          console.log(
-            "There was an error creating a CesiumGeohash model" +
-              ". Error details: ",
-            error
-          );
+        } catch (e) {
+          console.log("Error creating a CesiumGeohash model. ", e);
         }
       },