Sails.js for web development

Sails.js is a robust web development framework that runs on top of Node.js and uses JavaScript’s asynchronous features to speed up the production of applications. Its adherence to the Model-View-Controller (MVC) architecture, which simplifies feature separation and code organization, is a critical component of its attractiveness. Rapid application development is facilitated by Sails.js’ pre-built components and user-friendly APIs for developers. The framework is robust in scenarios involving real-time communication, which makes it perfect for interactive applications. Its Object-Relational Mapping (ORM) technology facilitates smooth integration with different databases by streamlining database interactions. Sails.js abstracts complexity and provides flexibility and scalability for projects of any size, from small-scale apps to large-scale business solutions, freeing developers to concentrate on application logic and user experience.

Because it doesn’t rely on any particular frontend technology, Sails is referred to as a frontend-agnostic backend platform. This increases the versatility with which developers can operate. It is ideal for developing single-page and real-time web applications since it leverages for effective WebSocket communication and Express for handling HTTP queries. Sails streamline the process of creating custom applications, freeing up developers to concentrate on innovative concepts and finish projects on time.

Features and characteristics of sails.js

In this section I will introduce some of the things that make sails.js a good fit for using in your development projects.

Convention over configuration: Sails.js minimizes setup by offering default settings and sensible conventions. This frees developers from time-consuming configuration procedures so they can concentrate on developing their applications’ business logic.

Automatic RESTful API Generation: It excels in its ability to generate RESTful APIs from models effortlessly. By simply creating a model, developers can quickly build controller actions and CRUD (Create, Read, Update, Delete) routes. This straightforward process simplifies the creation of API endpoints for data manipulation. 

Real-time Communication: WebSockets-based real-time communication is supported natively by Sails.js. This enables programmers to create apps that enable linked clients to receive real-time data changes. Sails.js uses the “pub/sub” (publish/subscribe) paradigm to facilitate real-time messaging between clients and the server.

Database Flexibility: Because Sails.js is database-agnostic, it can operate with a wide range of databases, including PostgreSQL, MongoDB, MySQL, and more. Developers can use the Waterline ORM to easily integrate any database with Sails.js, regardless of which database best meets their application’s needs.

Ecosystem and extensibility: It boasts a thriving community that produces a vast array of plugins and modules. These plugins offer new features and integrations to Sails.js, extending its capability. Because Sails.js is scalable, developers may use the ecosystem to improve their apps. Sails.js gives developers the tools they need to create scalable, maintainable, and real-time online apps quickly by adhering to these fundamental ideas. Offering conventions, automatic API construction, real-time connectivity, and database flexibility simplifies the development process and frees up developers to concentrate on building dependable, feature-rich applications.

MVC Architecture in Sails.js

In Sails.js, the MVC architecture is implemented to separate your application’s concerns into distinct modules covering Model, View and the controller. In this section, I will give an overview of how these parts of the architecture are structured in Sails.js:

  • Model (M):
    • In Sails.js, a model typically represents a single table in the underlying database. However, it can be associated with multiple tables or data structures through relationships defined in the model configurations.
    • The Model represents your application’s data layer. It defines your data’s structure and schema and interacts with the database to perform CRUD (Create, Read, Update, Delete) operations.
    • You can define your models using Waterline, which is an ORM used in Sails.js to abstract away the details of database interactions.
    • Models in Sails.js are typically stored in the api/models directory and are defined using JavaScript files.
  • View (V):
    • View in Sails.js represents the user interface layer of your application. It includes the HTML, CSS, and client-side JavaScript code that is rendered and presented to users.
    • Sails.js uses EJS (Embedded JavaScript) as the default templating engine for views. EJS allows you to embed JavaScript code directly into your HTML templates, making it easy to generate dynamic content.
    • Views are stored in the views directory and are typically organized based on the routes and controllers they correspond to.
  • Controller (C):
    • Controllers in Sails.js are responsible for handling user requests, processing data from models, and rendering views to send back responses to clients.
    • Each controller corresponds to a specific route or group of routes in your application. Controllers contain action methods that define the logic for handling different HTTP requests (e.g., GET, POST, PUT, DELETE).

Controllers are stored in the api/controllers directory and are defined using JavaScript files. You can also create nested controllers to organize your code more effectively.

Getting started with Sails.js

Getting started with Sails.js involves a few key steps to set up your development environment, create a new Sails.js project, and start building your application. Below is a beginner’s guide to getting started with Sails.js:

  1. Install Node.js and npm:
    • Before you can use Sails.js, you need to have Node.js and npm installed on your machine.
  2. Install Sails.js globally:
    • Once Node.js is installed, open your terminal or command prompt and install Sails.js globally using npm:

      npm install -g sails

  3. Create a new Sails.js project:
    • After installing Sails.js globally, navigate to the directory where you want to create your Sails.js project using the terminal or command prompt.
    • Run the following command to generate a new Sails.js project:

      sails new my-sails-project

      Replace my-sails-project with the desired name of your project.

  4. Navigate to the project directory:
    • Go to the project directory after the project has been created, using the cd command:

      cd my-sails-project

  5. Start the Sails.js server:
    • To start the Sails.js server and run your application, use the following command:

      sails lift

      By doing this (usually 1337), the server will start on the default port and you can access your Sails.js application in your web browser at http://localhost:1337.

  6. Explore the project structure:
    • Inside your Sails.js project directory, you will find various folders and files that make up the structure of your application.
      • api/: Contains controllers, models, policies, services, and other backend-related files.
      • config/: Has configuration files for routes, database connections, environment settings, etc.
      • views/: It contains views (HTML, EJS, or other templating files) for your application’s frontend.
      • assets/: Consists of static assets such as CSS, JavaScript, images, etc.
  7. Start building your application:
    • With the Sails.js server running, you can start building your application by creating models, controllers, routes, views, and adding business logic as needed.
    • Use the Sails.js documentation and community resources to learn more about the framework and its features.
  8. Install additional dependencies:
    • Depending on your project requirements, you may need to install additional npm packages and dependencies. Use npm to install packages as needed:

      npm install package-name –save

    • Replace package-name with the name of the npm package you want to install.
  9. Deploy your Sails.js application:
    • Once you have developed and tested your Sails.js application locally, you can deploy it to a production server or a hosting platform of your choice. Follow the deployment guides and best practices provided in the Sails.js documentation.

Example MVC Architecture Code

Here’s an example of how the MVC architecture is structured might be coded for a very simple Sails.js application that has a model of a user with firstName, lastName, email, and password fields:

In this example:

  • The Model (User.js) defines the attributes of a User model.
  • The Controller (UserController.js) contains action methods like create and findOne to handle user requests.
  • The View (create.ejs) provides a form for creating a new user and sends a POST request to the /user/create route, which is handled by the create action in the UserController.

Benefits of adhering to MVC architecture

In this section, I will outline some of the larger values of using the MVC architecture. The concepts of for code organization and separating the different concerns of the application into different layer for easier management, testing, and reusability.

Code Organization: MVC provides a clear structure for organizing code, which makes it easier for developers to understand and navigate the application’s architecture.

Models handle data manipulation and interaction with the database, views manage the user interface, and controllers manage the application logic and handle user requests.

Separation of Concerns: MVC enforces a separation of concerns by assigning specific responsibilities to each component. Models handle data validation, storage, retrieval, and business logic related to data manipulation. Views are in charge of managing user interface interactions and presenting data to users. Finally, Controllers act as intermediaries between models and views, handling user requests, processing data, and coordinating interactions between different components.

Testing Capabilities: MVC architectures facilitate effective testing strategies, including unit testing, integration testing, and end-to-end testing. Components can be tested in isolation, allowing for more targeted and comprehensive testing of each part of the application. This leads to higher code quality, reduced bugs, and improved reliability of the software.

Code Reusability: With MVC, components are designed to be reusable across different parts of the application or even in other projects.

Models encapsulate data logic and can be reused for various operations related to data manipulation and storage. Views can be reused to display data in different contexts or formats without duplicating code. Controllers can handle common application logic and workflows, promoting code reusability across different user interactions.

Enhanced Maintainability: Because MVC encourages a clear separation of concerns, developers can concentrate on different parts of the application which are; data handling, user interface, application logic, etc., at different times.

This separation lowers the possibility of creating unexpected side effects or compromising already-existing functionality by making code easier to comprehend, alter, and maintain over time.

Scalability and Flexibility: MVC architectures are inherently scalable as they allow for the addition of new features or modules without significant changes to existing code. The separation of concerns enables developers to expand individual components separately, making it easier to manage complex programs and accommodate future expansion or changes in needs.

Adaptability to Change: MVC architectures are adaptable to changes in requirements, technology updates, or business needs. Developers can modify or extend individual components without affecting the overall architecture, minimizing disruption and ensuring smooth transitions.

Utilizing Sails.js ORM features for efficient data retrieval and manipulation

Sails.js comes with a powerful ORM called Waterline, which provides efficient data retrieval and manipulation capabilities. Here are some key features of Sails.js ORM and how you can utilize them for efficient data handling:

Model Definition:

Define your data models using Waterline’s ORM syntax, specifying attributes, data types, validations, and associations between models.


Configuring data storage:

Configure your database connections in the config/datastores.js file to specify the database adapter, connection settings, and model associations.

Database Agnostic:

Waterline is database-agnostic, meaning you can switch between different database systems (e.g., MySQL, PostgreSQL, MongoDB) without changing your application code. After generating a user model from your installed Sails.js app.

sails generate model user

Examples database configurations

Here’s an illustration of how you might configure your config/models.js file to use different databases.

For MySQL:

For PostgreSQL:

For MongoDB:

Replace user, password, localhost, database_name, and the database-specific URLs with your actual database credentials and configurations.

After configuring the models.js file, you can start your Sails.js app and it will use the specified database system based on the configuration provided. For example:

sails lift

You can further customize and expand this setup based on your application’s requirements and the specific features of each database system.

Querying Data

Use Waterline’s query methods to retrieve data from the database efficiently which is writing code that optimizes the performance of database queries.


Data Manipulation:

Waterline provides methods for creating, updating, and deleting records in the database.


Validation and Constraints

Define validation rules and constraints for model attributes to ensure data integrity and consistency.


Association Handling:

Define associations between models (e.g., one-to-one, one-to-many, many-to-many) to establish relationships and perform related data operations. Use populate queries to fetch associated records along with the main record efficiently.


In the example provided, we have two models; User and Post. These models represent entities in our application, where a User can have multiple Posts (one-to-many relationship), and each Post belongs to a single User (many-to-one relationship).

Here’s how the association is defined in the models:

User Model:

In the User model, we define a one-to-many association with the Post model. The 'posts' attribute specifies a collection of Post records, and the 'via' key indicates the association is established through the 'author' attribute in the Post model.

Post Model:

In the Post model, we define a many-to-one association with the User model. The ‘author’ attribute specifies the User model as the related model, indicating that each Post record is associated with a single User.

Now, let’s see how we can use these associations and populate queries to fetch associated records efficiently.

Example Query:

In this example query, we use Waterline’s populate method to fetch a User record with the specified id (1) and populate the post’s association. This means that along with the User record, all associated Post records will be fetched and included in the result.

Leveraging Sails.js ORM features like Waterline allows you to handle data retrieval, manipulation, validation, associations, and database operations efficiently in your application, leading to better code organization, scalability, and maintainability.

Best practices in Sails.js development

When developing applications with Sails.js, there are several best practices that you should follow to ensure efficient, maintainable, and scalable code. Here are some key best practices in Sails.js development:

Follow MVC Architecture: Adhere to the Model-View-Controller (MVC) architecture to separate concerns and keep your code organized. Place models in the api/models directory, controllers in the api/controllers directory, and views in the views directory.

Use Async/Await or Promises: Prefer using async/await or promises (then/catch) for handling asynchronous operations like database queries, API calls, and file I/O.

This helps in writing cleaner and more readable asynchronous code compared to callbacks.

Implement Validations: Define validations for model attributes using Waterline’s built-in validation rules or custom validation functions.

Validate user input and data integrity to prevent invalid or malicious data from entering your application.

Optimize Database Queries: Use Waterline’s query methods efficiently to optimize database queries and minimize the number of database calls.

Use populate to fetch associated records in a single query instead of making separate queries for related data.

Use Policies for Authorization: Implement policies to handle authorization logic and restrict access to certain routes or controller actions based on user roles and permissions.

Define policies in the api/policies directory and apply them to controller actions using route policies or global policies.

Enable CSRF Protection: Enable Cross-Site Request Forgery (CSRF) protection to prevent unauthorized requests from malicious sites. Use the configuration option to enable CSRF protection and configure token settings.

Handle Errors Gracefully: Implement error handling middleware or use try-catch blocks to properly handle mistakes and give users insightful error messages. Use Sails.js’ error response methods like res.serverError, res.badRequest, and res.notFound to send appropriate error responses.

Use Environment-based Configuration: Use environment-based configuration files (e.g., config/env/development.js, config/env/production.js) to manage different configurations for development, staging, and production environments.

Implement Logging: Implement logging using Sails.js’ built-in logger or external logging libraries to track application events, errors, and performance metrics.

Log important information, warnings, errors, and debug messages to aid in troubleshooting and monitoring.

Optimize Asset Management: Use asset pipelines or build tools like Grunt or Gulp to optimize and manage front-end assets like CSS, JavaScript, and images. Minify, concatenate, and cache static assets to improve page load times and reduce bandwidth usage.


Sails.js provides developers with a powerful toolkit and a structured approach to web development, making it a valuable choice for building modern and dynamic web applications. 

It is a popular Node.js MVC framework that is meant to mimic the well-known MVC paradigm of frameworks like Ruby on Rails while accommodating the needs of contemporary applications. It differs from other Node.js frameworks in that it has several essential features.