initial commit

lib/utils.ts

@@ -0,0 +1,58 @@
+import { clsx, type ClassValue } from "clsx";
+import { twMerge } from "tailwind-merge";
+
+export function cn(...inputs: ClassValue[]) {
+  return twMerge(clsx(inputs));
+}
+
+/**
+ * The implementation for pagination queries in an array.
+ * @param array Array input
+ * @param pageSize Max elements count for every page.
+ * @param pageNumber The current page number.
+ * @returns A new array contains elements of specified page.
+ */
+export function paginateArray<T = any>(array: T[], pageSize: number, pageNumber: number) {
+  if (array.length === 0) return [];
+  if (pageSize < 1) return [];
+  if (pageNumber < 1) return [];
+
+  --pageNumber;
+
+  const startIndex = pageNumber * pageSize;
+  const endIndex = (pageNumber + 1) * pageSize;
+
+  if (startIndex >= array.length) return [];
+
+  return array.slice(startIndex, endIndex);
+}
+
+/**
+ * Nullify the empty string and convert them into `null`.
+ * @param value Possible string input.
+ * @returns return `null` if the input belongs to "", undefined and null.
+ */
+export function nullifyEmptyString(value: string | null | undefined): string | null {
+  if (value == null) {
+    return null;
+  }
+  if (value.trim() === "") {
+    return null;
+  }
+  return value;
+}
+
+/**
+ * Indicate whether a string is empty value.
+ * @param value Possible string input.
+ * @returns return `true` if the input belongs to "", undefined and null.
+ */
+export function isEmptyString(value: string | null | undefined): boolean {
+  if (value == null) {
+    return true;
+  }
+  if (value.trim() === "") {
+    return true;
+  }
+  return false;
+}