Set column captions when reading grid from a design file (#8770)

Fixes #8752

server/src/main/java/com/vaadin/ui/Grid.java

@@ -87,6 +87,7 @@ import com.vaadin.shared.ui.grid.GridConstants;
 import com.vaadin.shared.ui.grid.GridConstants.Section;
 import com.vaadin.shared.ui.grid.GridServerRpc;
 import com.vaadin.shared.ui.grid.GridState;
+import com.vaadin.shared.ui.grid.GridStaticCellType;
 import com.vaadin.shared.ui.grid.HeightMode;
 import com.vaadin.shared.ui.grid.ScrollDestination;
 import com.vaadin.shared.ui.grid.SectionState;
@@ -102,6 +103,7 @@ import com.vaadin.ui.components.grid.FooterRow;
 import com.vaadin.ui.components.grid.GridSelectionModel;
 import com.vaadin.ui.components.grid.Header;
 import com.vaadin.ui.components.grid.Header.Row;
+import com.vaadin.ui.components.grid.HeaderCell;
 import com.vaadin.ui.components.grid.HeaderRow;
 import com.vaadin.ui.components.grid.ItemClickListener;
 import com.vaadin.ui.components.grid.MultiSelectionModel;
@@ -3892,6 +3894,16 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
                 getFooter().readDesign(child, context);
             }
         }
+
+        // Sync default header captions to column captions
+        if (getDefaultHeaderRow() != null) {
+            for (Column<T, ?> c : getColumns()) {
+                HeaderCell headerCell = getDefaultHeaderRow().getCell(c);
+                if (headerCell.getCellType() == GridStaticCellType.TEXT) {
+                    c.setCaption(headerCell.getText());
+                }
+            }
+        }
     }
 
     protected void readData(Element body,

server/src/test/java/com/vaadin/tests/server/component/grid/GridDeclarativeTest.java

@@ -802,11 +802,9 @@ public class GridDeclarativeTest extends AbstractListingDeclarativeTest<Grid> {
 
             // Property mapping
             Assert.assertEquals(expectedColumn.getId(), column.getId());
-            // Not tested because of
-            // https://github.com/vaadin/framework/issues/8752
             // Header caption
-            // Assert.assertEquals(expectedColumn.getCaption(),
-            // column.getCaption());
+            Assert.assertEquals(expectedColumn.getCaption(),
+                    column.getCaption());
 
             // Value providers are not stored in the declarative file
             // so this only works for bean properties