feat(sort): sort on a value returned by the column

cypress/integration/column.js

@@ -35,6 +35,29 @@ describe('Column', function () {
         cy.clickDropdownItem(2, 'Reset sorting');
     });
 
+    it('sorts on the value returned by a column sortValue hook', function () {
+        // Sort the Name column by surname instead of the cell content.
+        cy.window().then(win => {
+            win.datatable.getColumn(2).sortValue = cell => String(cell.content).split(' ').pop();
+        });
+
+        cy.clickDropdown(2);
+        cy.clickDropdownItem(2, 'Sort Ascending');
+
+        cy.window().then(win => {
+            const datamanager = win.datatable.datamanager;
+            const surnames = datamanager.rowViewOrder
+                .map(rowIndex => String(datamanager.getCell(2, rowIndex).content).split(' ').pop());
+
+            expect(surnames).to.deep.equal([...surnames].sort());
+        });
+
+        cy.clickDropdownItem(2, 'Reset sorting');
+        cy.window().then(win => {
+            delete win.datatable.getColumn(2).sortValue;
+        });
+    });
+
     it('removes column using dropdown action', function () {
         cy.get('.dt-cell--header').should('have.length', 12);
 

src/datamanager.js

@@ -283,14 +283,18 @@ export default class DataManager {
             }
         }
 
+        const sortValue = cell => {
+            const hook = cell.column && cell.column.sortValue;
+            const value = hook ? hook(cell) : cell.content;
+            return value == null ? '' : value;
+        };
+
         this.rowViewOrder.sort((a, b) => {
             const aIndex = a;
             const bIndex = b;
 
-            let aContent = this.getCell(colIndex, a).content;
-            let bContent = this.getCell(colIndex, b).content;
-            aContent = aContent == null ? '' : aContent;
-            bContent = bContent == null ? '' : bContent;
+            const aContent = sortValue(this.getCell(colIndex, a));
+            const bContent = sortValue(this.getCell(colIndex, b));
 
             if (sortOrder === 'none') {
                 return aIndex - bIndex;