rk

Ruby helper to generate keys for Redis, based on an idea by @stockholmux and this implementation for Node.js.

Use this library to avoid typos when building Redis keys!

Installation

gem install rk

Usage

Simple

Just use rk to build a key with the default separator : (colon).

require "redis"
require "rk"

redis = Redis.new

userid = 10
redis.set(rk("user", userid), "John Doe") # key is "user:10"

Advanced

Use a prefix and/or suffix for keys.

require "redis"
require "rk"

redis = Redis.new

rk.prefix = "myapp"
rk.suffix = "test"
rk.separator = "-"

userid = 10
redis.set(rk("user", userid), "John Doe") # key is "myapp-user-10-test"

Even more advanced

Define key elements with rk and avoid typos even in key names!

require "redis"
require "rk"

redis = Redis.new

rk.prefix = "myapp"
rk.suffix = "test"
rk.user = "user"

userid = 10
redis.set(rk(rk.user, userid), "John Doe") # key is "myapp:user:10:test"

This is what happens if you access a self defined key that does not exist (on typo):

require "redis"
require "rk"

redis = Redis.new

rk.stats = "stats"

redis.incr(rk(rk.stat, 1)) # typo here, accessing 'stat' instead of 'stats'
=> RuntimeError: 'rk.stat' is undefined

Use rk.keys to assign multiple keys with a hash (for example loaded from a configuration file):

require "redis"
require "rk"

redis = Redis.new

rk.keys = { user: "user", "statistics" => "stats", "session" => :sess }

rk.user # => "user"
rk.statistics # => "stats"
rk.session # => "sess"

userid = 10
redis.set(rk(rk.session, 10), "a3nc4E1f") # key is "sess:10"

Options

You may want to use these options (methods):

Method	Default value	Example
prefix or prefix=	"" (empty)	rk.prefix => "" or rk.prefix = "myapp"
suffix or suffix=	"" (empty)	rk.suffix => "" or rk.suffix = "test"
separator or separator=	:	rk.separator => ":" or rk.separator = "-" (use minus as separator for parts of the key)
keys or keys=	[] (empty)	rk.keys = { user: "usr", group: "grp" }; rk.user => "usr" and rk.group => grp and rk.keys => { "user" => "usr", "group" => "grp" }
any other	RuntimeError (if undefined)	rk.user = "usr"; rk.user => "usr" or rk.something => RuntimeError: 'rk.something' is undefined