Merge pull request #18 from integration-os/feat/pagination-helper

feat: add pagination helper

generator/templates/index.handlebars

@@ -4,6 +4,7 @@ import { convertFilterToQueryParams } from './utils';
 
 export * from './types/generic';
 export * from './types/models';
+export * from './paginate';
 
 import { 
   {{#each resources}}

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@integrationos/node",
-  "version": "4.1.9",
+  "version": "4.1.10",
   "description": "Node SDK for the IntegrationOS Unified API",
   "main": "dist/src/index.js",
   "types": "dist/src/index.d.ts",

src/index.ts

@@ -4,6 +4,7 @@ import { convertFilterToQueryParams } from './utils';
 
 export * from './types/generic';
 export * from './types/models';
+export * from './paginate';
 
 import { 
     Events, 

src/paginate.ts

@@ -0,0 +1,67 @@
+import { ListFilter, PaginationHelperFetch } from "./types";
+
+export class PaginationHelper<T> {
+    private currentBatch: T[] = [];
+    private nextBatch: T[] | null = null;
+    private currentCursor: string | undefined;
+    private nextCursor: string | undefined;
+    private isInitialized: boolean = false;
+
+    private defaultBatchSize: number = 25
+
+    constructor(
+        private fetchFunction: PaginationHelperFetch<T>,
+        private listParams: ListFilter = {
+            limit: this.defaultBatchSize
+        }
+    ) { }
+
+    async initialize(): Promise<void> {
+        if (this.isInitialized) return;
+
+        const firstResponse = await this.fetchFunction({ ...this.listParams });
+        this.currentBatch = firstResponse.unified;
+        this.currentCursor = firstResponse.pagination.nextCursor;
+
+        if (this.currentCursor) {
+            const secondResponse = await this.fetchFunction({
+                ...this.listParams,
+                cursor: this.currentCursor
+            });
+
+            this.nextBatch = secondResponse.unified;
+            this.nextCursor = secondResponse.pagination.nextCursor;
+        }
+
+        this.isInitialized = true;
+    }
+
+    async getNextBatch(): Promise<T[]> {
+        if (!this.isInitialized) {
+            await this.initialize();
+        }
+
+        const batchToReturn = this.currentBatch;
+        this.currentBatch = this.nextBatch || [];
+        this.currentCursor = this.nextCursor;
+
+        if (this.currentCursor) {
+            const response = await this.fetchFunction({
+                ...this.listParams,
+                cursor: this.currentCursor
+            });
+
+            this.nextBatch = response.unified;
+            this.nextCursor = response.pagination.nextCursor;
+        } else {
+            this.nextBatch = null;
+            this.nextCursor = undefined;
+        }
+
+        return batchToReturn;
+    }
+
+    hasMoreData(): boolean {
+        return this.currentBatch.length > 0 || (this.nextBatch !== null && this.nextBatch.length > 0);
+    }
+}

src/types/generic.ts

@@ -21,6 +21,8 @@ export interface Pagination {
     previousCursor?: string;
 }
 
+export type PaginationHelperFetch<T> = (params: ListFilter) => Promise<ListResponse<T>>;
+
 export interface DeleteOptions {
     modifyToken?: string;
 }