TOBAGO-1633: TS refactoring
diff --git a/tobago-theme/tobago-theme-standard/src/main/npm/ts/tobago-sheet.ts b/tobago-theme/tobago-theme-standard/src/main/npm/ts/tobago-sheet.ts
index 392d3fc..0f36d8d 100644
--- a/tobago-theme/tobago-theme-standard/src/main/npm/ts/tobago-sheet.ts
+++ b/tobago-theme/tobago-theme-standard/src/main/npm/ts/tobago-sheet.ts
@@ -89,9 +89,9 @@
       const tokens = JSON.parse(element.dataset["tobagoLayout"]).columns;
       const columnRendered = this.isColumnRendered();
 
-      const headerCols = element.querySelectorAll(".tobago-sheet>header>table>colgroup>col");
-      const bodyTable = <HTMLElement>element.querySelector(".tobago-sheet>div>table");
-      const bodyCols = element.querySelectorAll(".tobago-sheet>div>table>colgroup>col");
+      const headerCols = this.getHeaderCols();
+      const bodyTable = this.getBodyTable();
+      const bodyCols = this.getBodyCols();
 
       console.assert(headerCols.length - 1 === bodyCols.length, "header and body column number doesn't match");
 
@@ -436,6 +436,22 @@
     });
   };
 
+  getHeaderTable():HTMLElement {
+    return this.getElement().querySelector(".tobago-sheet>header>table");
+  };
+
+  getHeaderCols():NodeListOf<HTMLElement> {
+    return this.getElement().querySelectorAll(".tobago-sheet>header>table>colgroup>col");
+  };
+
+  getBodyTable():HTMLElement {
+    return this.getElement().querySelector(".tobago-sheet>div>table");
+  };
+
+  getBodyCols():NodeListOf<HTMLElement> {
+    return this.getElement().querySelectorAll(".tobago-sheet>div>table>colgroup>col");
+  };
+
   static hideInputOrSubmit = function ($input) {
     let $output = $input.siblings(".tobago-sheet-pagingOutput");
     let changed = $output.html() !== $input.val();