34 catalog pagination backend (#42)

* Modified /catalog get request to accept limit and page parameter for pagination

Co-authored-by: Maithy Le <[email protected]>

* Modified /catalog get to return data and amount of events

Co-authored-by: Maithy Le <[email protected]>

* merge catalog query+filter with pagination

---------

Co-authored-by: Maithy Le <[email protected]>
Co-authored-by: ThatMegamind <[email protected]>
Co-authored-by: michellelin1 <[email protected]>

common/utils.js

@@ -20,6 +20,11 @@ const isISODate = (str) => {
   }
 };
 
+// dependency for catalog.js
+const isInteger = (value) => {
+  return value && /^\d+$/.test(value);
+};
+
 const isObject = (o) => {
   return o === Object(o) && !isArray(o) && typeof o !== 'function' && !isISODate(o);
 };
@@ -52,4 +57,4 @@ const keysToCamel = (data) => {
   return data;
 };
 
-module.exports = { keysToCamel };
+module.exports = { keysToCamel, isInteger };

routes/catalog.js

@@ -1,15 +1,22 @@
 const express = require('express');
-
 const { db } = require('../server/db');
 
 const catalogRouter = express.Router();
-const { keysToCamel } = require('../common/utils');
-// modify /catalog
+const { keysToCamel, isInteger } = require('../common/utils');
+
 // -- GET - Returns all data from the catalog table
 catalogRouter.get('/', async (req, res) => {
   try {
     const { title, eventType, subject, season, year } = req.query;
-    let query = 'SELECT * FROM catalog WHERE 1=1';
+
+    let { limit, page } = req.query;
+    limit = isInteger(limit) ? parseInt(limit, 10) : 10;
+    page = isInteger(page) ? parseInt(page, 10) : 1;
+
+    const offset = (page - 1) * limit;
+
+    let query = ' FROM catalog WHERE 1=1';
+
     const params = [];
 
     if (title) {
@@ -47,10 +54,15 @@ catalogRouter.get('/', async (req, res) => {
       params.push('');
     }
 
-    query += ' ORDER BY title ASC';
+    const eventCount = await db.query(`SELECT COUNT(*) ${query};`, params);
+
+    query += ' ORDER BY title ASC LIMIT $6 OFFSET $7;';
+    params.push(limit);
+    params.push(offset);
+
+    const reqInfo = await db.query(`SELECT * ${query}`, params);
 
-    const reqInfo = await db.query(query, params);
-    res.status(200).json(keysToCamel(reqInfo));
+    res.status(200).json(keysToCamel({ events: reqInfo, count: eventCount }));
   } catch (err) {
     res.status(500).send(err.message);
   }