Creating a Simple Blog Application in Perl

 create simple blog application that allows users to create, read, update, and delete (CRUD) blog posts. The application uses the Perl Catalyst MVC framework, DBIx::Class ORM for interacting with the database, and provides both REST and GraphQL APIs for accessing the data. The database can be  PostgreSQL.

Example1:

use Catalyst::Runtime '5.90124';

use Catalyst;

__PACKAGE__->config(

    name => 'MyBlogApp',

    default_view => 'HTML',

    'View::HTML' => {

        INCLUDE_PATH => [

            __PACKAGE__->path_to('root', 'src'),

        ],

    },

);

__PACKAGE__->setup();

1;

package MyBlogApp::Controller::API;

use Moose;

use namespace::autoclean;

BEGIN { extends 'Catalyst::Controller::REST'; }

__PACKAGE__->config(

    default => 'application/json',

    map => {

        'application/json' => 'JSON',

    },

);

sub blog :Path('/api/blog') :Args(0) :ActionClass('REST') {}

sub blog_GET {

    my ($self, $c) = @_;

    # Retrieve blog posts from the database

    my @blog_posts = $c->model('DB::BlogPost')->all;

    # Return the blog posts as JSON

    $self->status_ok($c, entity => \@blog_posts);

}

sub blog_POST {

    my ($self, $c) = @_;

    # Create a new blog post

    my $blog_post = $c->model('DB::BlogPost')->create({

        title => $c->req->data->{title},

        content => $c->req->data->{content},

    });

    # Return the created blog post as JSON

    $self->status_created(

        $c,

        location => $c->uri_for('/api/blog', $blog_post->id),

        entity => $blog_post,

    );

}

__PACKAGE__->meta->make_immutable;

1;

package MyBlogApp::Controller::GraphQL;

use Moose;

use namespace::autoclean;

BEGIN { extends 'Catalyst::Controller'; }

sub execute :Path('/graphql') :Args(0) {

    my ($self, $c) = @_;

    # Execute the GraphQL query

    my $result = $c->model('DB')->execute_graphql(

        $c->req->data->{query},

        $c->req->data->{variables},

    );

    # Return the result as JSON

    $c->res->content_type('application/json');

    $c->res->body($result);

}

__PACKAGE__->meta->make_immutable;

1;

package MyBlogApp::Model::DB;

use strict;

use base 'Catalyst::Model::DBIC::Schema';

__PACKAGE__->config(

    schema_class => 'MyBlogApp::Schema',

    connect_info => [

        'dbi:Pg:dbname=myblogapp',

        'username',

        'password',

        {

            AutoCommit => 1,

            RaiseError => 1,

        },

    ],

);

1;

package MyBlogApp::Schema::Result::BlogPost;

use strict;

use warnings;

use base 'DBIx::Class::Core';

__PACKAGE__->table('blog_posts');

__PACKAGE__->add_columns(

    id => {

        data_type => 'integer',

        is_auto_increment => 1,

    },

    title => {

        data_type => 'varchar',

        size => 255,

    },

    content => {

        data_type => 'text',

    },

);

__PACKAGE__->set_primary_key('id');

1;

package MyBlogApp::Schema;

use strict;

use warnings;

use base 'DBIx::Class::Schema';

__PACKAGE__->load_namespaces;

1;

we have created a simple blog application using the Perl Catalyst MVC framework. The application allows users to perform CRUD operations on blog posts and provides both REST and GraphQL APIs for accessing the data.

The application uses the DBIx::Class ORM to interact with the PostgreSQL database. The MyBlogApp::Model::DB module configures the database connection, and the MyBlogApp::Schema module defines the database schema.

The MyBlogApp::Controller::API module handles the REST API endpoints for retrieving and creating blog posts. The blog_GET method retrieves all blog posts from the database and returns them as JSON. The blog_POST method creates a new blog post based on the request data and returns the created blog post as JSON.

The MyBlogApp::Controller::GraphQL module handles the GraphQL API endpoint. The execute method executes the GraphQL query and returns the result as JSON.

Overall, this code provides a solid foundation for building a simple blog application in Perl using the Catalyst framework.