Setup

Setup: As new project

Clear offers a CLI (Command Line Interface) which is still in Alpha. Documentation for building a new project with Clear + Kemal will be written once the feature is done. As of now, you can just follow the paragraph below.

Setup: In existing project

$ crystal init app <yourappname>
$ cd <yourappname>

In `shard.yml`

Add your dependency in the dependencies list of your shard.yml

/shard.yml

dependencies:
  clear:
    github: anykeyh/clear
    branch: master

Then download the library:

terminal

$ shards install

In your source code

Assuming your main entry point of your application is src/main.cr , you can require and initialize Clear:

src/main.cr

# append to your require list on top:
require "clear"

# initialize a pool of database connection:
Clear::SQL.init("postgres://postgres@localhost/my_database", 
    connection_pool_size: 5)

Step by Step

• require "clear" load the source code of Clear and provide everything needed to use the library.

• Clear::SQL.init prepare a certain number of connection to your database. The URL is a convention used to connect to the database, and follow this schema:

postgres://USER[:PASSWORD]@HOST/DATABASE[?*OPTIONS]

More information about the URL notation can be found here

• connection_pool_size: 5 is optional but offers the possibility to concurrent fibers to run query at the same time. It's useful if you use an event-driven server, like Kemal.

Installation customization

You may want to install a smaller version of Clear by calling :

require "clear/core"

This will add clear without the build-in CLI and without some extensions (jsonb, bcrypt etc...).