wordcount-note.js

const AWS = require('aws-sdk');
AWS.config.update({ region: 'us-west-1' });

const _ = require('underscore');
const util = require('./util.js');

const dynamodb = new AWS.DynamoDB.DocumentClient();
const tableName = process.env.NOTES_TABLE;

exports.handler = async (event) => {
    try {

        //decode function helps to format any encoded special characters and avoid any error regarding the same
        let note_id = decodeURIComponent(event.pathParameters.note_id);

        // Index note_id is used below which is usually used to optimize the query and the item retrieval

        let params = {
            TableName: tableName,
            IndexName: "note_id-index",
            KeyConditionExpression: "note_id = :note_id",
            ExpressionAttributeValues: {
                ":note_id": note_id
            },
            Limit: 1
        };

        let data = await dynamodb.query(params).promise();

        //This will count all the words in one note's content section
        
        if(!_.isEmpty(data.Items)) {
            let noteContent = data.Items[0].content;
            let wordCount = noteContent.split(/\s+/).length;

            return {
                statusCode: 200,
                headers: util.getResponseHeaders(),
                body: JSON.stringify({ wordCount: wordCount })
            };
        } else {
            return {
                statusCode: 404,
                headers: util.getResponseHeaders()
            };
        }      
    } catch (err) {
        console.log("Error", err);
        return {
            statusCode: err.statusCode ? err.statusCode : 500,
            headers: util.getResponseHeaders(),
            body: JSON.stringify({
                error: err.name ? err.name : "Exception",
                message: err.message ? err.message : "Unknown error"
            })
        };
    }
}