clicking on map without reaction produced error

when no results were returned for search by coordinates, there was exception thrown

Closes #149 (closed)

frontend-js/src/main/js/map/overlay/SearchDbOverlay.js

@@ -119,8 +119,9 @@ SearchDbOverlay.prototype.searchByCoordinates = function(params) {
     var searchResult = null;
     var maxDistance;
 
+    var model = self.getMap().getSubmapById(modelId).getModel();
     return ServerConnector.getMaxSearchDistance().then(function(distance) {
-      var maxZoom = self.getMap().getSubmapById(modelId).getModel().getMaxZoom();
+      var maxZoom = model.getMaxZoom();
       var zoomDiff = maxZoom - zoom;
       for (var i = 0; i < zoomDiff; i++) {
         distance = distance * 1.5;
@@ -131,33 +132,42 @@ SearchDbOverlay.prototype.searchByCoordinates = function(params) {
         coordinates : coordinates,
         count : 1
       });
-    }).then(
-        function(elements) {
-          var nestedOverlay = "Pathways and compartments";
-          if (self.getMap().getBackgroundDataOverlay().getName() === nestedOverlay) {
-            return self._getFirstVisibleParentOrObject(elements[0], zoom
-                - self.getMap().getSubmapById(modelId).getModel().getMinZoom());
-          } else {
-            return elements[0];
-          }
-        }).then(function(visibleObject) {
-      searchResult = [ visibleObject ];
-      if (searchResult[0].getType() === "REACTION") {
-        var model = self.getMap().getSubmapById(searchResult[0].getModelId()).getModel();
-        return model.getReactionById(searchResult[0].getId(), true).then(function(reaction) {
-          var i = 0;
-          var reactionElements = reaction.getElements();
-          for (i = 0; i < reactionElements.length; i++) {
-            searchResult.push(new IdentifiedElement(reactionElements[i]));
-          }
-        });
+    }).then(function(elements) {
+      var nestedOverlay = "Pathways and compartments";
+      if (elements.length === 0) {
+        return undefined;
+      } else {
+        if (self.getMap().getBackgroundDataOverlay().getName() === nestedOverlay) {
+          return self._getFirstVisibleParentOrObject(elements[0], zoom - model.getMinZoom());
+        } else {
+          return elements[0];
+        }
+      }
+    }).then(function(visibleObject) {
+      if (visibleObject !== undefined) {
+        searchResult = [ visibleObject ];
+        if (searchResult[0].getType() === "REACTION") {
+          return model.getReactionById(searchResult[0].getId(), true).then(function(reaction) {
+            var i = 0;
+            var reactionElements = reaction.getElements();
+            for (i = 0; i < reactionElements.length; i++) {
+              searchResult.push(new IdentifiedElement(reactionElements[i]));
+            }
+          });
+        }
+      } else {
+        searchResult = [];
       }
     }).then(function() {
-      return self.getMap().getDistance({
-        modelId : modelId,
-        coordinates : coordinates,
-        element : searchResult[0],
-      });
+      if (searchResult.length > 0) {
+        return self.getMap().getDistance({
+          modelId : modelId,
+          coordinates : coordinates,
+          element : searchResult[0],
+        });
+      } else {
+        return Number.POSITIVE_INFINITY;
+      }
     }).then(function(distance) {
       if (distance <= maxDistance) {
         self._elementsByQuery[query] = searchResult;