MetaRecord

MetaRecord is a code generator that allows you to define your application models using a Ruby-powered DSL, and generates various implementation for them, for your web server, client, or mobile application.

It can generates code for the following targets:

• Crails-ODB
• ActiveRecord
• Comet.cpp
• Aurelia.js
• Qt

MetaRecord is useful to speed up development of Crails and Comet application development by generating most of the models code for you.

It is also useful as a way to share the database structure data and the validations behaviors between frontend and backend.

Install

gem install 'meta-record'

source 'https://rubygems.org'

gem 'meta-record', github: 'crails-framework/meta-record'

Commands

Use the metarecord-make command to generate code for your models:

  metarecord-make -i input/models -o output/models -g qt,aurelia

MetaRecord DSL

Example of a model definition using MetaRecord's DSL:

add_include "app/models/user.hpp", include_in_header: true

Model.add 'Event' do
  order_by 'starts_at'

  visibility :protected
  property 'std::string', 'name'
  property 'std::time_t', 'starts_at'
  property 'double',      'duration', validate: { min: 0 }
  property 'bool',        'enabled', default: true

  has_one  "::User", "owner", validate: { required: true }, read_only: true
  has_many "::User", "subscribers"
end

property

Property declares a new property for your model. Parameters are :

• Type: the standard C++ type. Non-C++ generators will deduce their own native type from this.
• Name: the property name
• Options

Available options:

• default: the property's default value
• read_only: boolean hinting client generators that the property can only be modified by a server application
• validate: an object containing validation details
• db: an object containing database options

Database options:

• transient: a boolean option determining whether the property should be backed in database or not. Set to true so the property won't be persisted. Default is false.
• default: this is the database default value for the property, used in the SQL schema.
• null: a boolean detemining whether an SQL column may accept null or not.
• column: column name to use in SQL databases.
• type: SQL type to use

has_one

Describes a one to one relationship with another MetaRecord model. This helper will create an id property to store the remote model's id within the current model.

has_many

Describes a one to many relationship with another MetaRecord model.

order_by

Defines the property that should be used by default to sort the models when querying the database.

Optionally, you may pass a second parameter :asc or :desc to change the ordering of the sort.

resource_name

Allows you to set a resource_name for your model. By default, it will be deduced from the model's name. The resource name is used when converting or reading data from json: a collection parser for a given model will expect to find a key matching the resource_name in any json it receives.

The resource name configured here should be singular. It will be pluralized depending on context (parsing one or multiple models).

visibility

This command allows you to determine the visibility of the next properties you'll declare. Accepted values are :public, :protected and :private.