refactor(app): move react components to react codebase [EE-3179] (#6971)

app/react/components/PaginationControls/generatePagesArray.ts

@@ -0,0 +1,55 @@
+import { calculatePageNumber } from './calculatePageNumber';
+
+export /**
+ * Generate an array of page numbers (or the '...' string) which is used in an ng-repeat to generate the
+ * links used in pagination
+ *
+ * @param currentPage
+ * @param rowsPerPage
+ * @param paginationRange
+ * @param collectionLength
+ * @returns {Array}
+ */
+function generatePagesArray(
+  currentPage: number,
+  collectionLength: number,
+  rowsPerPage: number,
+  paginationRange: number
+): (number | '...')[] {
+  const pages: (number | '...')[] = [];
+  const totalPages = Math.ceil(collectionLength / rowsPerPage);
+  const halfWay = Math.ceil(paginationRange / 2);
+
+  let position;
+  if (currentPage <= halfWay) {
+    position = 'start';
+  } else if (totalPages - halfWay < currentPage) {
+    position = 'end';
+  } else {
+    position = 'middle';
+  }
+
+  const ellipsesNeeded = paginationRange < totalPages;
+
+  for (let i = 1; i <= totalPages && i <= paginationRange; i += 1) {
+    const pageNumber = calculatePageNumber(
+      i,
+      currentPage,
+      paginationRange,
+      totalPages
+    );
+
+    const openingEllipsesNeeded =
+      i === 2 && (position === 'middle' || position === 'end');
+    const closingEllipsesNeeded =
+      i === paginationRange - 1 &&
+      (position === 'middle' || position === 'start');
+    if (ellipsesNeeded && (openingEllipsesNeeded || closingEllipsesNeeded)) {
+      pages.push('...');
+    } else {
+      pages.push(pageNumber);
+    }
+  }
+
+  return pages;
+}