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Perl Webdev

BUILD A WEBAPPS with Perl, Dancer2, AND Carton

In the Perl ecosystem, Dancer2 is one of the most popular frameworks for building web applications due to its simplicity and flexibility. Coupled with Carton, which manages dependencies in an isolated environment, you can create scalable and organized web apps. This article walks you through the process, ensuring your project structure is correct and maintainable

Why Choose Dancer2?

Dancer2 stands out for several reasons: 1. Minimal Configuration: It's easy to set up and start developing immediately, letting you focus on building rather than configuring. 2. Built-in Support for REST: Building APIs or interacting with external systems is straightforward. 3. Rich Plugin Ecosystem: There’s an abundance of plugins to extend your app without extra complexity.

Project Setup: Step-by-Step

1. Create Your Project Directory

First, create a new directory for your project and move into it: 

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mkdir MyWebApp
cd MyWebApp

2. Install Carton

Install Carton if it’s not already installed: 

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cpanm Carton

3. Create a cpanfile

Within your project folder, create a file called cpanfile to define the dependencies for your app: 

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requires 'Dancer2';

This file will help Carton handle dependency management for your project.

4. Install Dependencies

After setting up the cpanfile, install the defined dependencies with Carton: 

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carton install
This will install Dancer2 and any related modules into the local project environment.

5. Initialize Your Dancer2 Application

Now that Dancer2 is available locally, use it to initialize the project structure: 

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carton exec dancer2 -a MyWebApp
This command will generate a scaffold for your web application with directories such as:

  • bin/ contains the script to run your app.
  • lib/ your application logic.
  • views/ templates for rendering HTML.

6. Basic Application Example

In the bin/app.pl file, you'll find a basic starter code. You can modify it like this to create a simple greeting app: 

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#!/usr/bin/env perl
use Dancer2;

get '/' => sub {
    return 'Hello, World!';
};

get '/greet/:name' => sub {
    my $name = param('name');
    return "Hello, $name!";
};

start;
This simple app provides two routes: - / returns "Hello, World!" - /greet/:name returns a personalized greeting.

7. Run the Application

You can now run the app with Carton: 

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carton exec perl bin/app.pl
The app will run at http://localhost:3000. To test it, open a browser and visit: - http://localhost:3000/ for "Hello, World!" - http://localhost:3000/greet/YourName for a personalized greeting.

Managing Dependencies with Carton

Carton ensures that all dependencies are stored locally within the project. This prevents conflicts between different projects or system-level packages, keeping your environment clean. Each time you want to run or modify the app, use carton exec to ensure it uses the locally installed modules.

You can easily build well-organized and isolated web applications. Properly managing dependencies in application development provides a solid foundation for building more complex web applications in the future (from what I've learned so far). This is just a part of my practical implementation of learning the Perl language.