README

This repository contains a simple tool to boot CodeIgniter projects with YAML config.

Motivation

There are two types of configuration: declarative and executed (so it's basically a big function that somehow provides configuration to application, either via return or side-effects). While executed configuration (which is used by CodeIgniter) gives infinite freedom to end user (you can compute values on-the-fly), it lacks the ability of easy machine processing that declarative configuration has, and limits your freedom in automation. Declarative configuration, such as YAML files, is static, but can be easily created by a script using any language, and gives huge benefit for automating things like continuous deployments and automated environment creation (for feature branches, for example).

Because we had some troubles deploying our CodeIgniter projects from scratch, i decided to help CodeIgniter to switch to YAML for configuration.

Installation

Just the usual thing:

composer require ama-team/yamligniter

Usage

CodeIgniter takes it's config by letting user to fill some variables in user-maintained scripts. Let's exploit that:

// application/config/config.php

extract(AmaTeam\YamlIgniter::config(__DIR__ . '/config.yml'));

// application/config/database.php

extract(AmaTeam\YamlIgniter::database(__DIR__ . '/database.yml');

You can now also use environment-based configuration files:

// application/config/database.php

extract(AmaTeam\YamlIgniter::database(__DIR__ . '/' . ENVIRONMENT . '/database.yml');

YamlIgniter will take your configuration, fill the missing gaps with default values, and then return full config to you for future processing or extraction into local variables.

Formals

Static methods YamlIgniter::database() and YamlIgniter::config() are just wrappers around similar non-static methods: they've been implemented solely for simplified access. Their implementation differ a little - ::config() simply reads YAML file, fills all gaps with default values and returns in an array under config key:

# config.yml
base_url: https://project.dev/

# results in
config:
  base_url: 'http://project.dev/'
  index_page: 'index.php'
  uri_protocol: 'REQUEST_URI'
  ...

Database method acts differently. The source config file should represent database.php structure:

# database.yml
query_builder: true
db:
  default:
    username: johnny
    password: rubber
    database: project
    failover:
      - username: johnny
        password: rubber
        database: project
        hostname: failover-host.intranet

YamlIgniter then takes this input and transforms as described:

Merges root context with defaults for framework version (in current example, active_group: default would be added to config)
Iterates over all entries of db, merging every entry with default database context
Iterates over all entries of db.*.failover, merging every entry with default database context

So above example would result in:

query_builder: true
active_group: default
db:
  default:
    dsn: ''
    hostname: localhost
    username: johnny
    password: rubber
    database: project
    dbdriver: mysqli
    ...
    failover:
      - dsn: ''
        username: johnny
        password: rubber
        database: project
        hostname: failover-host.intranet
        dbdriver: mysqli
        ...