julionav / lazyrecord

Laziest clone of ActiveRecord

LazyRecord

LazyRecord is the simplest and laziest implementation of the ActiveRecord pattern, but without the database, nor the relationships (I said it was a lazy implementation).

Instead of a database, it uses the file based data storage PStore.

LazyRecord is a teaching tool for the M of MVC, it allows to have models that have persistence, without having knowledge of SQL.

Installation

gem install lazyrecord

Usage

To create a model, inherit from LazyRecord.

You can add properties as you do with any class.

class Post < LazyRecord
  def initialize(title:, body:)
    @title = title
    @body = body
  end
end

Now you can create Post that have a #save method to persist them to the database.

post = Post.new(title: "LazyRecord is the new ActiveRecord replacement", body: "Says no one")
post.save
puts post.id # The post has an id now

You can also use the #create shortcut to generate the object and save it

post = Post.create(title: "LazyRecord is the new ActiveRecord replacement", body: "Says no one")
puts post.id # The post has an id now

You can find a record by id.

post = Post.find(1)

You can delete a record by id

Post.delete(1)

You can get all the posts as an array:

posts = Post.all

You can find records by passing a block to find (it works exactly the same as Array#find)

Since the class method ::all returns all the elements as an array, you can do any operation that Arrays allow.

posts = Post.all

posts.sort_by { |post| post.title } # Also posts.sort_by(&:title)
posts.filter { |post| post.title.match? /LazyRecord/ }
# And so on...

FAQ

Should I use LazyRecord in production?

If you want to keep your job, no.

Should I use LazyRecord as a teaching tool before using ActiveRecord?

Sure!

Will LazyRecord be the new ActiveRecord?

Maybe!

lazyrecord's Issues

NoMethodError at /create undefined method `+' for nil:NilClass

Al eliminar la el archivo donde se almacena la info y al intentar, luego, usar el método create

Fields declaration

Models attributes should be declarable by using an attribute :attribute_name method inside the model.

So instead of doing:

class Post
  attr_accessor :title, :body

  def initialize(title:, body:)
    @title = title,
    @body = body
  end
end

post = Post.new(title: "Lazyrecord", body:"Body")

You can do:

class Post
  attribute :title
  attribute :body
end

post = Post.new(title: "Lazyrecord", body:"Body")

attribute should take a block to use as default value.

class Post
  attribute :title
  attribute :body
  attribute :created_at { Time.now }
end

post = Post.new(title: "Lazyrecord", body:"Body")
post.title # Lazyrecord
post.body # Body
post.created_at # the result of Time.now

This should be doable following this lesson from RubyMonk

Allow to store multiple models

Currently the store does not allow to persist several models because each class writes a 'lazy record.store' and it keeps getting overwritten.

Remove debugging information

When the ::delete method is called on Store, there are a few logs that are generated.

Add delete method

A record should be able to delete itself with record#delete

post = Post.create()
post.delete!
Post.all # Doesn't return the deleted post