Added extra comments in code for changes #7031

src/core.js

@@ -1099,6 +1099,7 @@ export default function Core(rootElement, userSettings, rootInstanceSymbol = fal
  } else {
  const [row, prop, , newValue] = changes[i];
  const propToColResult = datamap.propToCol(prop);
+ // Populated data may contain indexes beyond current table boundaries.
  const col = propToColResult !== null ? propToColResult : prop;
  const cellProperties = instance.getCellMeta(row, col);
 
@@ -1188,7 +1189,8 @@ export default function Core(rootElement, userSettings, rootInstanceSymbol = fal
 
  while (column > instance.countCols() - 1) {
  const numberOfCreatedColumns = datamap.createCol(void 0, void 0, source);
- propToColResult = datamap.propToCol(changes[i][1]);
+ // Populated data may contain indexes beyond current table boundaries.
+ propToColResult = datamap.propToCol(prop);
  column = propToColResult !== null ? propToColResult : prop;
 
  if (numberOfCreatedColumns >= 1) {
@@ -2716,16 +2718,20 @@ export default function Core(rootElement, userSettings, rootInstanceSymbol = fal
  let physicalRow = this.toPhysicalRow(row);
  let physicalColumn = this.toPhysicalColumn(column);
 
+ // We can also get cell meta for indexes beyond current table boundaries.
  if (physicalRow === null) {
  physicalRow = row;
  }
 
+ // We can also get cell meta for indexes beyond current table boundaries.
  if (physicalColumn === null) {
  physicalColumn = column;
  }
 
  const colToPropResult = datamap.colToProp(column);
- const prop = colToPropResult !== null ? colToPropResult : column; // We can also get meta for columns beyond the table boundaries
+ // TODO: Should it be possible to get cell meta for index beyond the table boundaries when data is defined as
+ // array of objects? Will a column index represent properly the property (integer instead of string)?
+ const prop = colToPropResult !== null ? colToPropResult : column;
  const cellProperties = metaManager.getCellMeta(physicalRow, physicalColumn);
 
  // TODO(perf): Add assigning this props and executing below code only once per table render cycle.

src/dataSource.js

@@ -252,7 +252,9 @@ class DataSource {
  const dataRow = this.modifyRowData(row);
  let prop = column;
 
+ // Please keep in mind that we may get data by physical index or by key when we store data as array of objects.
  if (Number.isInteger(column)) {
+ // When we store data as array of arrays a physical index is also a property.
  prop = this.colToProp(column);
  }
 

src/editors/dropdownEditor.js

@@ -21,9 +21,10 @@ class DropdownEditor extends AutocompleteEditor {
  }
 }
 
-Hooks.getSingleton().add('beforeValidate', function(value, row, col) {
- const propToColResult = this.propToCol(col);
- const column = propToColResult !== null ? propToColResult : col;
+Hooks.getSingleton().add('beforeValidate', function(value, row, prop) {
+ const propToColResult = this.propToCol(prop);
+ // Populated data may contain indexes beyond current table boundaries.
+ const column = propToColResult !== null ? propToColResult : prop;
  const cellMeta = this.getCellMeta(row, column);
 
  if (cellMeta.editor === DropdownEditor) {

src/pluginHooks.js

@@ -927,7 +927,7 @@ const REGISTERED_HOOKS = [
  * @event Hooks#beforeValidate
  * @param {*} value Value of the cell.
  * @param {number} row Visual row index.
- * @param {string|number} prop Property name / column index.
+ * @param {string|number} prop Property name / physical column index.
  * @param {string} [source] String that identifies source of hook call
  * ([list of all available sources]{@link https://handsontable.com/docs/tutorial-using-callbacks.html#page-source-definition}).
  */