Avoid creating unnecessary placeholders for full refresh.

Polymer · Nov 5, 2015 · 996289a · 996289a
1 parent c5e1135
commit 996289a
Showing 1 changed file with 8 additions and 5 deletions.
diff --git a/src/lib/template/dom-repeat.html b/src/lib/template/dom-repeat.html
@@ -415,12 +415,13 @@
       }
       this._keySplices = [];
       this._indexSplices = [];
-      // Update final _keyToInstIdx, instance indices, and replace placeholders
+      // Update final _keyToInstIdx and instance indices, and
+      // upgrade/downgrade placeholders
       var keyToIdx = this._keyToInstIdx = {};
       for (var i=this._instances.length-1; i>=0; i--) {
         var inst = this._instances[i];
         if (inst.isPlaceholder && i<this._limit) {
-          inst = this._upgradePlaceholder(i, inst.__key__);
+          inst = this._insertInstance(i, inst.__key__);
         } else if (!inst.isPlaceholder && i>=this._limit) {
           inst = this._downgradeInstance(i, inst.__key__);
         }
@@ -484,6 +485,8 @@
           if (!inst.isPlaceholder && i < this._limit) {
             inst.__setProperty(this.as, c.getItem(key), true);
           }
+        } else if (i < this._limit) {
+          this._insertInstance(i, key);
         } else {
           this._insertPlaceholder(i, key);
         }
@@ -646,7 +649,7 @@
       });
     },
 
-    _generateInstance: function(idx, key) {
+    _stampInstance: function(idx, key) {
       var model = {
         __key__: key
       };
@@ -655,15 +658,15 @@
       return this.stamp(model);
     },
 
-    _upgradePlaceholder: function(idx, key) {
+    _insertInstance: function(idx, key) {
       var inst = this._pool.pop();
       if (inst) {
         // TODO(kschaaf): If the pool is shared across turns, parentProps
         // need to be re-set to reused instances in addition to item/key
         inst.__setProperty(this.as, this.collection.getItem(key), true);
         inst.__setProperty('__key__', key, true);
       } else {
-        inst = this._generateInstance(idx, key);
+        inst = this._stampInstance(idx, key);
       }
       var beforeRow = this._instances[idx + 1 ];
       var beforeNode = beforeRow && !beforeRow.isPlaceholder ? beforeRow._children[0] : this;