https://github.com/seandenigris/Simple-Persistence

https://github.com/seandenigris/Simple-Persistence

persistence pharo smalltalk

Last synced: about 2 months ago
JSON representation

• Host: GitHub
• URL: https://github.com/seandenigris/Simple-Persistence
• Owner: seandenigris
• License: mit
• Created: 2015-08-10T15:27:13.000Z (almost 9 years ago)
• Default Branch: master
• Last Pushed: 2024-04-04T08:20:11.000Z (3 months ago)
• Last Synced: 2024-05-02T05:22:15.766Z (2 months ago)
• Topics: persistence, pharo, smalltalk
• Language: Smalltalk
• Size: 152 KB
• Stars: 16
• Watchers: 2
• Forks: 3
• Open Issues: 12
• Metadata Files:
  • Readme: README.md
  • Funding: .github/FUNDING.yml
  • License: LICENSE

Lists

• awesome-pharo - Simple-Persistence - Simple file base persistence for when you don't quite need a database. (Databases)

README

        
# SimplePersistence

## Motivation

Most applications are designed for small businesses with small amounts of data. Therefore *most applications will never have to scale* (i.e. become the next Twitter), so *a relational database is overkill*. However, persisting by simply saving the image is slow and error-prone. This simple (one class) framework saves only your model. The idea is to use it as long as you can get away with, which may be forever!

This repository carries on the original work by Ramon Leon ([@gnaritas](https://github.com/gnaritas)), which started as this [an enlightening blog post](http://onsmalltalk.com/simple-image-based-persistence-in-squeak/).

## Installation

```smalltalk

Metacello new

	baseline: 'SimplePersistence';

	repository: 'github://seandenigris/Simple-Persistence';

	load.

```

# Usage

1. Subclass `SpFileDatabase`.

1. Your SpFileDatabase subclass should respond to class-side `#schema` with a collection of client classes (i.e. for which we will be handling persistence). For example:

	```smalltalk

	MyProjectDB class>>#schema

		^ {

			QuQuote. "a domain class that is part of our project"

			LivingLibraryDB "the DB from another project (LivingLibraryDB sbclass), which we will take over and persist as part of our model."

		}.

	```

1. All client classes (i.e. `QuQuote` and `LivingLibraryDB` above) must respond to `#spData` with the data to be persisted. SpFileDatabase subclasses get this for free. Here's an example of a domain client class implementation:

	```smalltalk

	MyDomainClass class>>#spData

		^ { self uniqueInstance. self tags }

	```

1. All client classes must respond to `#restoreFrom:` taking the data they gave us to persist as the argument. Note that this is not an API change for domain classes, but now `SpFileDatabase` subclasses use the same message (which they get for free), instead of `#restoreRepositories:`. Here is an example for the domain class in the point above:

	```smalltalk

	MyDomainClass class>>#restoreFrom: aCollection

		uniqueInstance := aCollection first.

		tags := aCollection second.

	```

# Users

- [Living Library](https://github.com/seandenigris/Living-Library) - see `LivingLibraryDB`

- [My People](https://github.com/seandenigris/My-People) - see `MyPeopleDB`

- [Resources-Live](https://github.com/seandenigris/Resources-Live) - see `ResourcesLiveDB`

- [The Project Project](https://github.com/seandenigris/The-Project-Project) - see `TheProjectProjectDB`