LiquidCMS

A block-based content management system built with Erlang/OTP and the Nitrogen Web Framework.

Pages are composed from reusable blocks using the MFA (Module-Function-Arguments) pattern, with an admin panel for managing pages, blocks, templates, assets, users, and roles. Data is stored in Mnesia with a Bootstrap-based frontend.

Features

Content Management

• Block-based page composition via MFA records
• WYSIWYG editor with customizable toolbar
• Template system with error pages (403, 404, 500)
• Multi-language support (i18n)
• XML sitemap generation

Administration

• Admin panel with CRUD interface for all entities
• Role-based access control (admin, editor, nobody)
• Database backup and restore
• Email form management

User Management

• Authentication with email confirmation
• Password reset via SMTP
• Role assignment per user

Frontend & Assets

• Asset management with CSS/JS minification
• Bootstrap UI (via Coldstrap)
• Configurable analytics (Google, Yandex, Hubspot)
• Social sharing integration
• Custom 404 page handling

Developer Experience

• Hot code reloading with sync
• Auto-install: first run creates Mnesia schema, tables, and seeds defaults
• Pluggable collection modules

Prerequisites

• Erlang/OTP 28.1.1 — a .tool-versions file is included for asdf
• Rebar3
• Git

Getting Started

git clone git@github.com:T0ha/LiquidCMS.git
cd LiquidCMS
rebar3 compile
rebar3 shell

• rebar3 compile fetches dependencies and copies Nitrogen static assets (via post-compile hook)
• rebar3 shell starts the nitrogen application using etc/sys.config
• On first run, the database is automatically initialized with schema, tables, and default data
• The server is available at http://localhost:8000

Project Structure

LiquidCMS/
├── etc/                    # Configuration files
│   └── sys.config          # OTP application config (port, paths, limits)
├── include/                # Header files (.hrl)
│   ├── cms.hrl             # CMS records (cms_mfa, cms_page, cms_user, etc.)
│   ├── db.hrl              # Database macros
│   └── records.hrl         # Custom element records
├── priv/                   # Private data
│   └── cms.config          # CMS smart extensions config
├── sample/                 # Sample configuration files
│   └── esmtp.config        # SMTP setup template (Gmail example)
├── src/
│   ├── cms_modules/        # Core CMS modules (admin, account, sitemap)
│   ├── collections/        # Pluggable content blocks (bootstrap, html5, router, analytics, social, ...)
│   ├── elements/           # Custom Nitrogen elements (CRUD, WYSIWYG)
│   ├── actions/            # Custom Nitrogen actions
│   ├── index.erl           # Main routing and page rendering
│   ├── db.erl              # Mnesia database operations
│   ├── nitrogen_main_handler.erl
│   └── ...
├── static/                 # Static assets (CSS, JS, images, fonts)
└── templates/              # HTML templates (error pages, mail, analytics)

Configuration

Server (etc/sys.config)

Setting	Default	Description
address	0.0.0.0	Bind address
port	8000	HTTP port
document_root	./static	Static file directory
max_post_size	100000000	Max POST body size (~100 MB)
max_file_size	100000000	Max upload file size (~100 MB)

SMTP (sample/esmtp.config)

Copy sample/esmtp.config to etc/esmtp.config and fill in your SMTP credentials. The sample is pre-configured for Gmail (port 465, SSL).

CMS Extensions (priv/cms.config)

Defines smart extensions for features like automatic sitemap XML generation.

Architecture

MFA Block Pattern — Pages are built from #cms_mfa{} records, each holding {Module, Function, Args}. At render time, the page module calls each block's MFA in sort order, producing a composable waterfall of Nitrogen elements.

Collections — Pluggable modules in src/collections/ that provide groups of related blocks (e.g., bootstrap, html5, analytics, social, router). Each collection exports functions that can be referenced as MFA blocks.

Database — Mnesia with disc_copies storage. Tables: cms_settings, cms_mfa, cms_template, cms_asset, cms_page, cms_user, cms_role, cms_form, cms_language.

Roles — Priority-based: admin (1000), editor (2000), nobody (10000). Lower number = higher privilege. Access control checks user role priority against page requirements.

Request Flow — Cowboy → Simple Bridge → nitrogen_main_handler → page module → MFA block waterfall → rendered HTML.

Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/my-feature)
3. Commit your changes
4. Push to the branch and open a Pull Request

For development, rebar3 shell starts with sync enabled for automatic hot code reloading on file changes.

License

This project does not currently include a license file. Please contact the maintainer for licensing information.