# marcelollerena/react-todo-app architecture

> Architecture diagram of the GitHub repository marcelollerena/react-todo-app, generated by GitDiagram from its file tree, README and a sample of source files (last updated 2026-06-12). It is an AI-made overview: check details against the source.

- Interactive diagram: https://gitdiagram.com/marcelollerena/react-todo-app
- Repository: https://github.com/marcelollerena/react-todo-app

## Overview

1. This repository is a small React single-page app scaffolded with Vite. The architecture is frontend-only: there is no backend, no API layer, and no database integration visible in the tree.

2. The application entry path is conventional for Vite React projects: `index.html` loads the app shell, `src/main.jsx` is the JavaScript entry point, and `src/App.jsx` is the top-level composition component. `vite.config.js` and `eslint.config.js` support build/dev tooling rather than runtime behavior.

3. The UI is split into a few self-contained feature components under `src/components`: a `clock`, a `counter`, and a `todo-app`. This suggests the app is structured as a set of demo widgets or exercises rather than one large domain application.

4. The `clock` feature appears to be a standalone presentational component. Its own `clock.module.css` indicates local component styling and a clear boundary between UI and shared styles.

5. The `counter` feature is more architectural than the clock. It has a dedicated context subsystem under `src/context/counter-provider`, including `counter-context.jsx`, `counter-provider.jsx`, and `use-counter.jsx`. That implies the counter state is lifted into a React Context Provider and consumed through a custom hook, so any nested counter UI can share state without prop drilling.

6. The counter feature itself lives in `src/components/counter/counter.jsx`, separated from the context implementation. This is a clean split between state management infrastructure and the visual/controller layer that renders the counter UI and triggers updates.

7. The `todo-app` feature is organized around a hook-driven state model. `src/components/todo-app/hooks/use-todo.jsx` suggests the core todo state and mutations are encapsulated in a custom hook, while `todo-app.jsx`, `todo-controllers.jsx`, and `todo.jsx` split the rendered list, controls, and item-level UI into distinct units.

8. The todo subsystem likely follows a “logic in hook, UI in components” boundary: the hook owns todo state and actions, controllers expose user operations, and the presentational components render the list/items. That makes the todo module easier to diagram as a flow from user events to hook state to UI updates.

9. Styling is mostly component-scoped via CSS modules for feature components, plus a shared `src/styles/global.css` for app-wide defaults. This indicates a mixed styling strategy: global baseline styles with locally encapsulated component styles.

10. `src/App.jsx` is the composition boundary where the feature subsystems are assembled into the page. For an architecture diagram, treat it as the orchestrator that wires together the clock, counter, and todo widgets rather than as a stateful subsystem itself.

11. `public/` is available for static assets served directly by Vite, but no additional runtime infrastructure is evident. The repository therefore has a simple client-side rendering flow: browser loads the Vite app, React mounts into the root DOM node, and the features manage their own local or context state.

12. The main architectural distinction in this repo is between three levels: app composition (`App`/`main`), feature modules (`clock`, `counter`, `todo-app`), and shared state infrastructure (`counter-provider`, todo hook). That separation is the key boundary to capture in a diagram.

Main entry points: [`src/App.jsx`](https://github.com/marcelollerena/react-todo-app/blob/main/src/App.jsx) (App), [`src/components/todo-app/todo-app.jsx`](https://github.com/marcelollerena/react-todo-app/blob/main/src/components/todo-app/todo-app.jsx) (Todo app), [`src/components/counter/counter.jsx`](https://github.com/marcelollerena/react-todo-app/blob/main/src/components/counter/counter.jsx) (Counter), [`src/components/todo-app/hooks/use-todo.jsx`](https://github.com/marcelollerena/react-todo-app/blob/main/src/components/todo-app/hooks/use-todo.jsx) (useTodo)

## Diagram (Mermaid)

```mermaid
flowchart TD

subgraph group_shell["App shell"]
  node_index_html["index.html<br/>entry doc<br/>[index.html]"]
  node_main_jsx["main.jsx<br/>bootstrap<br/>[main.jsx]"]
  node_app_jsx["App<br/>composition<br/>[App.jsx]"]
end

subgraph group_features["Features"]
  node_clock_comp["Clock<br/>presentational<br/>[clock.jsx]"]
  node_counter_comp["Counter<br/>ui widget<br/>[counter.jsx]"]
  node_todo_app["Todo app<br/>feature shell<br/>[todo-app.jsx]"]
  node_todo_ctrls["Todo controls"]
  node_todo_item["Todo item<br/>item view<br/>[todo.jsx]"]
end

subgraph group_state["Shared state"]
  node_counter_ctx["Counter context"]
  node_counter_provider["Counter provider"]
  node_use_counter["useCounter<br/>hook<br/>[use-counter.jsx]"]
  node_use_todo["useTodo<br/>hook<br/>[use-todo.jsx]"]
end

subgraph group_styles["Styles"]
  node_global_css["global.css<br/>global styles<br/>[global.css]"]
  node_clock_css["clock.css<br/>component styles<br/>[clock.module.css]"]
  node_counter_css["counter.css<br/>component styles<br/>[counter.module.css]"]
end

node_index_html -->|"loads"| node_main_jsx
node_main_jsx -->|"mounts"| node_app_jsx
node_app_jsx -->|"applies"| node_global_css
node_app_jsx -->|"renders"| node_clock_comp
node_app_jsx -->|"renders"| node_counter_comp
node_app_jsx -->|"renders"| node_todo_app
node_clock_comp -->|"styles"| node_clock_css
node_counter_comp -->|"styles"| node_counter_css
node_counter_comp -->|"consumes"| node_use_counter
node_use_counter -->|"reads"| node_counter_ctx
node_counter_provider -->|"provides"| node_counter_ctx
node_todo_app -->|"uses"| node_use_todo
node_todo_app -->|"coordinates"| node_todo_ctrls
node_todo_app -->|"renders"| node_todo_item
node_todo_ctrls -->|"dispatches"| node_use_todo
node_todo_item -->|"reads"| node_use_todo

click node_index_html "https://github.com/marcelollerena/react-todo-app/blob/main/index.html"
click node_main_jsx "https://github.com/marcelollerena/react-todo-app/blob/main/src/main.jsx"
click node_app_jsx "https://github.com/marcelollerena/react-todo-app/blob/main/src/App.jsx"
click node_global_css "https://github.com/marcelollerena/react-todo-app/blob/main/src/styles/global.css"
click node_clock_comp "https://github.com/marcelollerena/react-todo-app/blob/main/src/components/clock/clock.jsx"
click node_clock_css "https://github.com/marcelollerena/react-todo-app/blob/main/src/components/clock/clock.module.css"
click node_counter_comp "https://github.com/marcelollerena/react-todo-app/blob/main/src/components/counter/counter.jsx"
click node_counter_ctx "https://github.com/marcelollerena/react-todo-app/blob/main/src/context/counter-provider/counter-context.jsx"
click node_counter_provider "https://github.com/marcelollerena/react-todo-app/blob/main/src/context/counter-provider/counter-provider.jsx"
click node_use_counter "https://github.com/marcelollerena/react-todo-app/blob/main/src/context/counter-provider/use-counter.jsx"
click node_counter_css "https://github.com/marcelollerena/react-todo-app/blob/main/src/components/counter/counter.module.css"
click node_todo_app "https://github.com/marcelollerena/react-todo-app/blob/main/src/components/todo-app/todo-app.jsx"
click node_todo_ctrls "https://github.com/marcelollerena/react-todo-app/blob/main/src/components/todo-app/todo-controllers.jsx"
click node_todo_item "https://github.com/marcelollerena/react-todo-app/blob/main/src/components/todo-app/todo.jsx"
click node_use_todo "https://github.com/marcelollerena/react-todo-app/blob/main/src/components/todo-app/hooks/use-todo.jsx"

classDef toneNeutral fill:#f8fafc,stroke:#334155,stroke-width:1.5px,color:#0f172a
classDef toneBlue fill:#dbeafe,stroke:#2563eb,stroke-width:1.5px,color:#172554
classDef toneAmber fill:#fef3c7,stroke:#d97706,stroke-width:1.5px,color:#78350f
classDef toneMint fill:#dcfce7,stroke:#16a34a,stroke-width:1.5px,color:#14532d
classDef toneRose fill:#ffe4e6,stroke:#e11d48,stroke-width:1.5px,color:#881337
classDef toneIndigo fill:#e0e7ff,stroke:#4f46e5,stroke-width:1.5px,color:#312e81
classDef toneTeal fill:#ccfbf1,stroke:#0f766e,stroke-width:1.5px,color:#134e4a
class node_index_html,node_main_jsx,node_app_jsx toneBlue
class node_clock_comp,node_counter_comp,node_todo_app,node_todo_ctrls,node_todo_item toneAmber
class node_counter_ctx,node_counter_provider,node_use_counter,node_use_todo toneMint
class node_global_css,node_clock_css,node_counter_css toneRose
```

## Components

### App shell

Browser entry and React bootstrap.

- [index.html](https://github.com/marcelollerena/react-todo-app/blob/main/index.html): entry doc · Vite host page that loads the React app. · `index.html`
- [main.jsx](https://github.com/marcelollerena/react-todo-app/blob/main/src/main.jsx): bootstrap · React entry point that mounts the app. · `src/main.jsx`
- [App](https://github.com/marcelollerena/react-todo-app/blob/main/src/App.jsx): composition · Top-level page composition for the feature widgets. · `src/App.jsx`

### Features

Standalone UI widgets assembled by the app.

- [Clock](https://github.com/marcelollerena/react-todo-app/blob/main/src/components/clock/clock.jsx): presentational · Standalone clock widget. · `src/components/clock/clock.jsx`
- [Counter](https://github.com/marcelollerena/react-todo-app/blob/main/src/components/counter/counter.jsx): ui widget · Counter feature UI rendered by the app. · `src/components/counter/counter.jsx`
- [Todo app](https://github.com/marcelollerena/react-todo-app/blob/main/src/components/todo-app/todo-app.jsx): feature shell · Top-level todo feature composition. · `src/components/todo-app/todo-app.jsx`
- [Todo controls](https://github.com/marcelollerena/react-todo-app/blob/main/src/components/todo-app/todo-controllers.jsx): controls · User actions and command controls for todos. · `src/components/todo-app/todo-controllers.jsx`
- [Todo item](https://github.com/marcelollerena/react-todo-app/blob/main/src/components/todo-app/todo.jsx): item view · Presentation for an individual todo entry. · `src/components/todo-app/todo.jsx`

### Shared state

Context and hook infrastructure shared within features.

- [Counter context](https://github.com/marcelollerena/react-todo-app/blob/main/src/context/counter-provider/counter-context.jsx): context · Context object for sharing counter state. · `src/context/counter-provider/counter-context.jsx`
- [Counter provider](https://github.com/marcelollerena/react-todo-app/blob/main/src/context/counter-provider/counter-provider.jsx): provider · Supplies counter state to the component tree. · `src/context/counter-provider/counter-provider.jsx`
- [useCounter](https://github.com/marcelollerena/react-todo-app/blob/main/src/context/counter-provider/use-counter.jsx): hook · Consumer hook for counter state and actions. · `src/context/counter-provider/use-counter.jsx`
- [useTodo](https://github.com/marcelollerena/react-todo-app/blob/main/src/components/todo-app/hooks/use-todo.jsx): hook · Encapsulates todo state and mutations. · `src/components/todo-app/hooks/use-todo.jsx`

### Styles

Global and component-scoped styling.

- [global.css](https://github.com/marcelollerena/react-todo-app/blob/main/src/styles/global.css): global styles · App-wide baseline styling. · `src/styles/global.css`
- [clock.css](https://github.com/marcelollerena/react-todo-app/blob/main/src/components/clock/clock.module.css): component styles · Scoped styles for the clock widget. · `src/components/clock/clock.module.css`
- [counter.css](https://github.com/marcelollerena/react-todo-app/blob/main/src/components/counter/counter.module.css): component styles · Scoped styles for the counter widget. · `src/components/counter/counter.module.css`

## Connections

- index.html → main.jsx: loads · The host page loads the React entry script.
- main.jsx → App: mounts · Bootstraps the top-level app component.
- App → global.css: applies · App composition sits on top of global baseline styles.
- App → Clock: renders · The app assembles the clock widget into the page.
- App → Counter: renders · The app assembles the counter widget into the page.
- App → Todo app: renders · The app assembles the todo feature into the page.
- Clock → clock.css: styles · Clock UI uses its local CSS module.
- Counter → counter.css: styles · Counter UI uses its local CSS module.
- Counter → useCounter: consumes · Counter UI reads shared state through the custom hook.
- useCounter → Counter context: reads · The hook accesses the underlying counter context.
- Counter provider → Counter context: provides · Provider populates the shared counter context.
- Todo app → useTodo: uses · Todo feature delegates state and mutations to the hook.
- Todo app → Todo controls: coordinates · Feature shell wires controls into the todo flow.
- Todo app → Todo item: renders · Feature shell renders todo item views.
- Todo controls → useTodo: dispatches · Controls trigger todo actions through the hook.
- Todo item → useTodo: reads · Item UI is driven by the shared todo state model.