About The Project

This is my easy search-engine app. Includes 2 repositories (backend + frontend). It is built base on regex concept.

• I deployed my app by nginx server. You can check quickly. http://dhuy4rtmaker.space/
• Frontend repo: https://github.com/dhuyartmaker/search-engine-app

Built With

• NodeJS v20 (ExpressJs)
• ReactJs v18
• MongoDB (v4 upper)
• ChakraUI

Main concept

Search-engine app use Regex (Regular Exception) to search corpus - saved in MongoDB.

Some rules

• Search result must be contain all characters of input

• Can insert 1 or many characters to between characters - split by input. With pattern:

  /.*i.*n.*p.*u.*t.*/
  

• After get some result suitable with rule above from DB. Continue mark score forEach result by my rule

  0: "^" + word + "$"
  1: `(^${word}.{1}$)|(^.{1}${word}$)`
  2: `(^.{1}${word}.{1}$)|(^${word}.{2,3}$)|(^.{2,3}${word}$)`
  3: `^.{1,3}${word}.{1,3}$`
  4: ".{0,2}" + `${word}`.split("").join(".{1,2}") + ".{0,2}"
  

• That's mean, for example i have input - "open". I can create 5 option for search

  0 -> exact word "open"
  1 -> can insert 1 character before|after ".open"|"open."
  2 -> similar 1 score, but can have 2|3 characters + ".open."
  3 -> "...open..."
  4 -> After searching contain entire input, i start split and insert between them ".o.p.e.n."
  5 -> Sort follow score, If have over many result which have same as score, i will sort and get 3 shortest word
  6 -> If result < 3, i slice input. "open" -> "ope"
  7 -> Loop until found 3 result, if not get random.
  

• So at least, i can find 3 words contain a first character.

Notice:
    Score and size of result can be change easily to adapt with your require!

Getting Started

This is some step to install and prepare database

Installation

• After clone repository

  npm install
  

• Create config file follow sample

  src/config/config.json
  

  .env
  

• Start

  node server.js
  

Usage

Scripts

• First, I need insert corpus into DB. With command, replace file name in <<hemingway.txt>>. I prepared 2 file is hemingway.txt & corpus.txt.

  node scripts/add-corpus.js <<hemingway.txt>>
  

• Process will read file and split into many words. Many this word are duplicate checked by new Set(). After that, I chunk into data set and insert to DB thank to Promise.all.
• Notice*: If DB has many over ~20.000 word. Inserting by this scripts start to take a long time since before inserting, I need check if word is existed to avoid duplicated. In one paragraph, there are have many duplicate words. So, this is neccessary

Rest API

• There are 3 apis match with 3 options (search, update, delete)
• With delete: i use logic of search API and find this word.
• Please check Postman Documents https://documenter.getpostman.com/view/13827204/2s9XxwxumL