Changeset 33102 for main/trunk

Timestamp:

2019-05-22T16:58:53+12:00 (5 years ago)

Author:

wy59

Message:

In previous commits we weren't using the capabilities of the (hash)map. Now we finally make proper use of it to efficiently ensure the uniqueness of labels we put into the autocomplete list.

File:

• main/trunk/greenstone3/web/interfaces/default/js/map-scripts-editor.js (modified) (6 diffs)

main/trunk/greenstone3/web/interfaces/default/js/map-scripts-editor.js

@@ +1 @@
+// Global autocomplete labels list: one list for all the map editors' shape labels in a page
+// We use the global labels hashmap to more efficiently ensure uniqueness of labels in our autocomplete list
 var global_autocompleteLabelsList = [];
 var global_labels_hashmap = {};
@@ -183 +185 @@
 // Ensure only unique labels are added to our autocomplete list
 MapEditor.prototype.addToAutocompleteLabelsList = function (newLabel) {
-    if (newLabel !== "" && !global_autocompleteLabelsList.includes(newLabel)) {
+
+    // We use a hashmap to more efficiently ensure uniqueness of labels in our array
+    // https://stackoverflow.com/questions/11040472/how-to-check-if-object-property-exists-with-a-variable-holding-the-property-name
+    if (newLabel !== "" && !global_labels_hashmap.hasOwnProperty(newLabel)) { // label is not empty and unique, so
+        // add to hashmap now
+        global_labels_hashmap[newLabel] = 1;
         // add to autocomplete list and sort alphabetically
         global_autocompleteLabelsList.push(newLabel);
-        global_autocompleteLabelsList.sort();        
+        global_autocompleteLabelsList.sort();
     }
 }
@@ -500 +507 @@
             }
         }
-    ); // TODO: responseFunction in setMeta call
+    ); // responseFunctions are now in the setMeta calls
 }
 
@@ -801 +808 @@
     map_editor.overlays = new_overlays;
 
-    var local_labels_hashmap = {};
     for (var i=0; i<map_editor.overlays.length; i++) {
         var shape = map_editor.overlays[i];
 
         // set up the autocomplete list using saved labels/descriptions
-        //map_editor.addToAutocompleteLabelsList(shape.description); // inefficient in ensuring uniqueness of values, use (hash)map
-        if (shape.description !== "") {
-            local_labels_hashmap[shape.description] = 1;  // we just want the shape.description added to the map as key, don't care about value
-                                                    // so that we can maintain a list of unique descriptions
-        }
-
+        map_editor.addToAutocompleteLabelsList(shape.description); // now efficiently ensures uniqueness of values using (hash)map
+        
         // make the shapes selectable on load:
         if (ShapesUtil.overlayItemIsShape(shape)) {
@@ -822 +824 @@
 
     this.mapEditorHistory.presentOverlayPush();
-    
-    // DO NOT assign "this.autocompleteLabelsList = keys(local_labels_hashmap);"
-    // Because Javascript is like Java and (in this) like C, not like C++. JavaScript uses Call-By-Sharing for objects:
-    // when reference addresses that are overwritten inside functions,
-    // the new address local to the function is not remembered/visible back outside the function
-    // https://stackoverflow.com/questions/518000/is-javascript-a-pass-by-reference-or-pass-by-value-language
-    // Instead, push.apply=addAll elements of keys to our autocomplete list, see 
-    // https://stackoverflow.com/questions/35658464/what-is-the-equivalent-of-java-collection-addall-for-javascript-arrays/35658514
-
-    // Combining contents of one JavaScript Object/hashmap (or associative 'array') into another is also described as merging our JavaScript Objects, so see
-    // https://stackoverflow.com/questions/929776/merging-objects-associative-arrays
-    // We've decided to use the jQuery based suggested solution for merging hashmaps:
-    // $.extend(obj1, obj2); means obj1 = obj1 + obj2. Note: it additionally overwrites any existing properties in obj1 with new values in obj2.
-    $.extend(global_labels_hashmap, local_labels_hashmap);
-
-    // important to empty our global autocomplete labels list array
-    // See https://stackoverflow.com/questions/1232040/how-do-i-empty-an-array-in-javascript
-    // and https://www.jstips.co/en/javascript/two-ways-to-empty-an-array/
-    global_autocompleteLabelsList.length = 0;
-    
-    var keys = Object.keys(global_labels_hashmap);
-    global_autocompleteLabelsList.push.apply(global_autocompleteLabelsList, keys); // addAll keys to our global_autocompleteLabelsList (turns map's keys into array)
-    global_autocompleteLabelsList.sort();   
 }
 
@@ -888 +867 @@
 }
 
-// Having got our unique (set) of descriptions/labels, we're ready to set it up as the source for our autocomplete list
+// Global function that uses jquery to set the autocomplete list's data source to whatever's in our global autocomplete labels array
 $(function setupAutocompleteLabelsList() {
     // Overrides the default autocomplete filter function to