slight efficiency to showRowsByKeyVals

Author: ddooley

lib/DataHarmonizer.js

@@ -754,17 +754,13 @@ class DataHarmonizer {
         afterSelection: (row, column, row2, column2) => {
           // A change in selected row
           if (self.current_selection[0] != row) {
-            // Possibly focused key has changed child table's filter.
-            // Issue: need to cascade this down immediately to any
-            // subordinate table, otherwise if doing on-demand from a table's 
-            // perspective, then if such a table depends on an intermediate that
-            // hasn't been refreshed, we'll get a wrong display.
-
+            // Row has changed so possibly values that make up some other 
+            // table's foreign key has changed, so that table's view should
+            // be refreshed.
             Object.entries(this.context.getDependents(this.template_name))
             .forEach(([child_name, child]) => {
               // Dependent tables determine what parent foreign key values they
               // need to filter view by
-              console.log("showing", child_name)
               this.showRowsByKeyVals(child_name);
             });
           };
@@ -881,12 +877,11 @@ class DataHarmonizer {
   }
 
 
-
-  // Here we deal with adding rows that need foreign keys.
-  // Locate each foreign key and fetch its focused value, and copy into new
-  // records below.  
-  // If missing key value(s), prompt user to focus appropriate tab(s) row
-  // and try again.
+  /* Here we deal with adding rows that need foreign keys.  Locate each foreign
+   * key and fetch its focused value, and copy into new records below.  
+   * If missing key value(s) encountered, prompt user to focus appropriate 
+   * tab(s) row and try again.
+   */
   getForeignKeyValues(parents) {
     let required_selections = {};
     let errors = '';
@@ -1088,32 +1083,36 @@ class DataHarmonizer {
   }
 
   /* For given template name, show only rows that conform to that class's
-   * foreign key-value constraints;
+   * foreign key-value constraints.
+   * (Could make a touch more efficient by skipping if we can tell that a 
+   * given table's foreign key values haven't changed.)
    */
   showRowsByKeyVals(template_name) {
     const hotInstance = this.context.dhs[template_name].hot;
     const hiddenRowsPlugin = hotInstance.getPlugin('hiddenRows');
 
     // Ensure all rows are visible
-    hiddenRowsPlugin.showRows(hiddenRowsPlugin.getHiddenRows()); 
+    let oldHiddenRows = hiddenRowsPlugin.getHiddenRows()
 
     //Fetch key-values to match
     let parents = this.context.getParents(template_name);
     let [required_selections, errors] = this.getForeignKeyValues(parents);
     // arrayRange() makes [0, ... n]
-    let rowsToHide = arrayRange(0,hotInstance.countRows()) 
+    let rowsToHide = arrayRange(0, hotInstance.countRows()) 
     .filter((row) => {
       for (let [slot_name, value] of Object.entries(required_selections)) {
         const col = this.context.dhs[template_name].getColumnIndexByFieldName(slot_name);
         const cellValue = hotInstance.getDataAtCell(row, col);
-        console.log(template_name,row,slot_name, col,cellValue,value)
         if (cellValue != value)
           return true;
       }
     });
 
-    hiddenRowsPlugin.hideRows(rowsToHide); // Hide the calculated rows
-    hotInstance.render(); // Render the table to apply changes
+    if (rowsToHide != oldHiddenRows) {
+      hiddenRowsPlugin.showRows(oldHiddenRows); 
+      hiddenRowsPlugin.hideRows(rowsToHide); // Hide the calculated rows
+      hotInstance.render(); // Render the table to apply changes
+    }
   }
 
   renderSemanticID(curieOrURI, as_markup = false) {