Decision Compass

A frontend project built primarily with JavaScript, React, and CSS, designed to provide a user-friendly interface for decision-making workflows.

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Table of Contents

• Overview
• Tech Stack
• Getting Started
• Issues & Solutions
  • Frontend Issues
  • Backend Issues
• Contributing
• License

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Overview

dc-frontend is the client-side application for a decision support system. It allows users to register, log in, and interactively enter and evaluate alternatives and criteria to support structured decision processes.

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Tech Stack

This project uses the following technologies and libraries:

• JavaScript — Main programming language.
• React (^19.1.0) — For building dynamic user interfaces.
• React DOM (^19.1.0) — DOM bindings for React.
• React Router DOM (^7.6.1) — Client-side routing for React apps.
• React Icons (^5.5.0) — Icon library for React.
• Axios (^1.9.0) — Promise-based HTTP client for API requests.
• CSS — For styling (with likely Tailwind support via PostCSS).
• Vite (^6.3.5) — Fast development and build tool.
• ESLint (^9.25.0) — JavaScript/React code linting.
• @vitejs/plugin-react-swc (^3.9.0) — React plugin for Vite using SWC.
• Tailwind/PostCSS — Utility-first CSS with PostCSS integration.
• TypeScript types (for React) — Even if the codebase is JS, types are included for editor support.

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Getting Started

Prerequisites

• Node.js (recommend v18+)
• npm or yarn

Installation

git clone https://github.com/hyper-27/dc-frontend.git
cd dc-frontend
npm install
# or
yarn install

Running the App

npm run dev
# or
yarn dev

Building for Production

npm run build
# or
yarn build

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Issues & Solutions

Below are common issues encountered in both the frontend and backend, along with their diagnosis and solutions.

Frontend Issues

• AxiosError: Request failed with status code 400 during Login/Registration
  Diagnosis/Solution: Frontend AuthContext or login/register components not sending Content-Type: application/json header.

• Frontend console showed AxiosError: 400 but Network tab showed 200 OK for calculate-scores
  Diagnosis/Solution: Console error was stale; the actual problem was scores displaying as 0 on frontend due to missing backend data.

• Scores not displaying or updating correctly on frontend after calculate-scores returned non-zero values
  Diagnosis/Solution: Frontend's DecisionEditPage.jsx needed to correctly update options and decision.overallScore states with the received data.

• Lack of user input mechanism for individual alternative-criterion ratings
  Diagnosis/Solution: Implemented the "Ratings" input table UI, handleRatingChange, and handleSaveRatings logic in src/pages/DecisionEditPage.jsx.

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Backend Issues

• Initial Login/Registration Backend Errors (e.g., 400 Bad Request, 500 Internal Server Error):
  Diagnosis/Solution: authController.js needed correct data validation, user creation, and proper error handling/responses.

• Backend calculate-scores endpoint returning 400 Bad Request:
  Diagnosis/Solution: decisionController.js required robust validation for alternatives and criteria arrays before attempting calculations.

• Calculated scores were always 0 on the backend, even with 200 OK status:
  Diagnosis/Solution: decisionController.js's calculateScores relied on Rating documents, but no mechanism existed to save these ratings in the database.

• ReferenceError: addAlternative is not defined in backend/routes/decisionRoutes.js:
  Diagnosis/Solution: addAlternative (and other CRUD functions for subdocuments) were missing from/not exported by decisionController.js when the file was replaced.

• Lack of user input mechanism for individual alternative-criterion ratings (Backend Part):
  Diagnosis/Solution: Created Rating Mongoose model and implemented addRatings/getRatings in decisionController.js with corresponding API routes in decisionRoutes.js.

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Contributing

1. Fork this repository.
2. Create your feature branch (git checkout -b feature/YourFeature).
3. Commit your changes (git commit -am 'Add new feature').
4. Push to the branch (git push origin feature/YourFeature).
5. Create a new Pull Request.

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License

Specify your license here (MIT, Apache 2.0, etc).

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