NAME

Yancy - A simple CMS for administrating data

VERSION

version 0.004

SYNOPSIS

    ### Standalone app
    $ yancy daemon

    ### Mojolicious plugin
    use Mojolicious::Lite;
    plugin Yancy => { ... };

DESCRIPTION

Yancy is a simple content management system (CMS) for administering content in a database. Yancy accepts a configuration file that describes the data in the database and builds a website that lists all of the available data and allows a user to edit data, delete data, and add new data.

Yancy uses JSON Schema to define the data in the database. The schema is added to an OpenAPI specification which creates a REST API for your data.

Yancy can be run in a standalone mode (which can be placed behind a proxy), or can be embedded as a plugin into any application that uses the Mojolicious web framework.

Yancy can manage data in multiple databases using different backends (Yancy::Backend modules). Backends exist for Postgres via Mojo::Pg, MySQL via Mojo::mysql, and DBIx::Class, a Perl ORM

Standalone App

To run Yancy as a standalone application, you must create a yancy.conf configuration file that defines how to connect to your database and what the data inside looks like. See "CONFIGURATION" for details.

NOTE: Yancy does not have authentication or authorization built-in. If you want to control which users have access to data, you should use an HTTP proxy with these features.

Once the application is started, you can navigate to http://127.0.0.1:3000/admin to see the Yancy administration app. Navigate to http://127.0.0.1:3000/ to see the getting started page.

Rendering Content

In the standalone app, all paths besides the /admin application are treated as paths to templates.

The templates are found in the templates directory. You can change the root directory that contains the templates directory by setting the MOJO_HOME environment variable.

Template names must end with .format.ep where format is the content type (html is the default). You can render plain text (txt), JSON (json), XML (xml), and others.

Database content can be read by using the database helpers that Yancy provides.

• yancy->list( $collection ) - Get a list of items

• yancy->get( $collection, $id ) - Get a single item

• yancy->set( $collection, $id, $data ) - Update an item

• yancy->delete( $collection, $id ) - Delete an item

• yancy->create( $collection, $data ) - Create an item

Some example template code:

    %# Get a list of people
    % my @people = app->yancy->list( 'people' );

    %# Show a list of people names 
    <ul>
        % for my $person ( @people ) {
            <li><%= $person->{name} %></li>
        % }
    </ul>

    %# Get a single person with ID 1
    % my $person = app->yancy->get( 'people', 1 );

    %# Write the person's name to the page
    <p>Hi, my name is <%= $person->{name} %>.</p>

More information about Mojolicious helpers is available at Mojolicious::Guides::Rendering.

Mojolicious Plugin

For information on how to use Yancy as a Mojolicious plugin, see Mojolicious::Plugin::Yancy.

REST API

This application creates a REST API using the standard OpenAPI API specification. The API spec document is located at /api in the standalone app, and /yancy/api in the Mojolicious plugin.

CONFIGURATION

The Yancy configuration file is a Perl data structure. The individual parts are described below. An example configuration file looks like:

    {
        backend => 'pg://user@example.com/mydb',
        collections => {
            people => {
                type => 'object',
                properties => {
                    id => {
                        type => 'integer',
                        readOnly => 1,
                    },
                    name => { type => 'string' },
                    email => { type => 'string' },
                },
            },
        },
    }

Database Backend

The backend URL defines what database to use and how to connect to it. Each backend has its own format of URL, and some examples are shown below. See your backend's documentation for more information.

Postgres backend

    backend => 'pg://user@example.com/mydb',

MySQL backend

    backend => 'mysql://user@localhost/mydb',

DBIx::Class backend

    backend => 'dbic://My::Schema/dbi:SQLite:file.db',

Data Collections

The collections data structure defines what data is in the database. Each key in this structure refers to the name of a collection, and the value describe the fields for items inside the collection.

Each backend may define a collection differently. For a relational database like Postgres or MySQL, a collection is a table, and the fields are columns. For an ORM like DBIx::Class, the collections are ResultSet objects. For a document store like MongoDB, the collections are collections. See your backend's documentation for more information.

Collections are configured using JSON Schema. The JSON Schema defines what fields (properties) an item has, and what type of data those field have. The JSON Schema also can define constraints like required fields or validate strings with regular expressions. The schema can also contain metadata like a title, description, and even an example value. For more information on what can be defined, see the docs on JSON Schema.

For a collection named people that has 3 fields (an integer id and two strings, name and email), a minimal JSON schema will look like this:

    collections => {
        people => {
            properties => {
                id => {
                    type => 'integer',
                    readOnly => 1,
                },
                name => {
                    type => 'string',
                },
                email => {
                    type => 'string',
                },
            },
        },
    },

Generated Forms

Yancy generates input elements based on the type, and format of the object's properties.

• type => "boolean" - A Yes/No field

• type => "integer" - A number field (<input type="number" >)

• type => "number" - A number field (<input type="number" >)

• type => "string", format => "date" - A date field (<input type="date">)

• type => "string", format => "date-time" - A date/time field (<input type="datetime-local">)

• type => "string", format => "email" - A e-mail address (<input type="email">)

• type => "string", format => "url" - A URL input (<input type="url">)

• type => "string", format => "tel" - A telephone number (<input type="tel">)

Fields with an enum property will be translated to <select> elements.

Other schema attributes will be translated as necessary to the HTML input fields:

• title will be used to label the input field

• readOnly

• pattern

• minimum

• maximum

• minLength

• maxLength

Required Values

JSON Schema allows marking properties as required using the required property, which must be an array of property names.

    collections => {
        people => {
            required => [ 'name', 'email' ],
            properties => {
                id => {
                    type => 'integer',
                    readOnly => 1,
                },
                name => {
                    type => 'string',
                },
                email => {
                    type => 'string',
                },
            },
        },
    },

Required values will be marked as such in the HTML.

Example Values

Setting an example value makes it easier to add new data. When a user tries to add a new item, Yancy will fill in the data from the example key of the collection. This key holds an example object using fake data. As an example of our people collection:

    people => {
        example => {
            name => 'Philip J. Fry',
            email => 'fry@aol.com',
        },
        properties => { ... },
    },

Extended Collection Configuration

There are some extended fields you can add to your collection definition to control how it is treated by Yancy.

x-id-field

This key sets the name of the collection's ID field to use to uniquely identify individual items. By default, Yancy assumes the ID field is named id. If your collection uses some other identifier (e-mail address or username for example), you should set this configuration key.

    people => {
        'x-id-field' => 'email',
        properties => { ... },
    },

x-list-columns

This key should be an array of columns to display on the list view, in order. This helps put useful information on the list page.

    people => {
        'x-list-columns' => [ 'name', 'email' ],
        properties => { ... },
    },

SEE ALSO

JSON schema, Mojolicious

AUTHOR

Doug Bell <preaction@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2017 by Doug Bell.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

cpanm Yancy

perl -MCPAN -e shell
install Yancy