platform/README.md

Angel Configuration

Automatic YAML configuration loader for Angel.

About

Any web app needs different configuration for development and production. This plugin will search for a config/default.yaml file. If it is found, configuration from it is loaded into app.properties. Then, it will look for a config/$ANGEL_ENV file. (i.e. config/development.yaml). If this found, all of its configuration be loaded, and will override anything loaded from the default.yaml file. This allows for your app to work under different conditions without you re-coding anything. :)

Installation

In pubspec.yaml:

dependencies:
    angel_configuration: ^1.0.0

Usage

Example Configuration

# Define normal YAML objects
some_key: foo
this_is_a_map:
  a_string: "string"
  another_string: "string"
  

You can also load configuration from the environment:

# Loaded from the environment
system_path: $PATH

If a .env file is present in your configuration directory, then it will be loaded before applying YAML configuration.

Server-side Call loadConfigurationFile(). The loaded properties will be available in your application's properties map, which means you can access them like normal instance members.

main() {
  print(app.foo == app.properties['foo']); // true
}

An instance of Configuration will also be injected to your application, and it works the same way:

import 'dart:io';
import 'package:angel_framework/angel_framework.dart';
import 'package:angel_configuration/angel_configuration.dart';

main() async {
    Angel angel = new Angel();
    angel.configure(loadConfigurationFile()); // It's that easy!
    
    app.get('/foo', (Configuration config) {
      return config.some_key;
    });
}

loadConfigurationFile also accepts a sourceDirectory or overrideEnvironmentName parameter. The former will allow you to search in a directory other than config, and the latter lets you override $ANGEL_ENV by specifying a specific configuration name to look for (i.e. production).

This package uses package:merge_map internally, so existing configurations can be deeply merged.

Example:

# default.yaml
foo:
  bar: baz
  quux: hello
  
# production.yaml
foo:
  quux: goodbye
  yellow: submarine
  
# Propagates to:
foo:
  bar: baz
  quux: goodbye
  yellow: submarine

In the Browser

You can easily load configuration values within your client-side app, and they will be automatically replaced by a Barback transformer.

In your pubspec.yaml:

transformers:
- angel_configuration

In your app:

import 'package:angel_configuration/browser.dart';

main() async {
    print(config("some_key.other.nested_key"));
}

You can also provide a dir or env argument, corresponding to the ones on the server-side.