Standard settings — automatic settings loader

A standardised settings loader.

No more cp config.sample.json config.json !

Features

• Automatic: load of default settings.default.json file
• Easy: customization of default settings (settings.json file)
• Granular: customization of settings through runtime arguments (--port=3000 --name=foo)
• Fast: settings overide by environment variables
• Bulletproof: runs in node and electron

❓Why ?

Keep the original settings and tinker easily with your own settings.

The app you developped will present a settings/settings.default.json which will always be included.

A user, or a developer wanting to tweak the settings, create a settings.json and standard-settings will load it and merge it with your default settings.

If a key is missing in custom settings, it won't trigger any error, because the default value is in settings.default.json.

standard-settings offers multiple ways to change settings:

• a settings.json file,
• command line arguments,
• environment variables.

Discover below examples for usage and priority order.

🌍 Installation

npm install standard-settings --save
or
yarn add standard-settings

⚙ Configuration

In a project where you plan to allow easy and simple configuration option with a JSON file, create a folder named: settings. Inside this folder, create a settings.default.json. standard-settings will load this file by default. Then create your own settings value and store them inside a settings.json file. This file will override the value of the settings.default.json

Do not forget to put the settings/settings.json inside your .gitignore file.

Default files names

These files are always loaded if present:
settings/settings.json first
settings/settings.default.json

Settings Load override order

As per standard-settings rules, environement variable will always take precedence over keys that could be set by command line argument or via file

1. The settings.default.json file which is in settings folder of your main app

2. The settings.json file which is in settings folder of your main app

3. Via a setting file through the command line

   Example:

   $ node index.js --settings settings/settings.prod.json to specify a settings file wich will override server.port

4. Via command line parameters (argv)

   Example:

   $ node index.js --server.port 2000 to specify a field

   This means that if you pass a settings file with --settings argument, the target key will override the value in the settings.

5. Environment variables

   Example:

   $ SERVER_PORT=2500 node index.js
$ service_spacebro_inputMessage=new-media node index.js

   $SERVER_PORT=6666 node examples/index.js --settings ./settings/settings.production.json --server.port 2000

   Here, the SERVER_PORT env will always win. You'll endup with a 6666 value for the key portof the key server

   This means that if you pass a settings file with --settings argument, or a target key with command line like --server.port the environment variable will be the final value.

👋 Usage inside Node.js or Electron

We recommand to require it at the very beginning of your project file:

  const standardSettings = require('standard-settings')

Then your settings are accessible from any file in your project using:

  const settings = standardSettings.getSettings()

If you need to directly access a specific field inside your settings, you can use:

  const port = standardSettings.get('server:port')

Under the hood, it is exactly the same as nconf.

API

getSettings()

• returns: full settings, environement included (JSON Object)
• description: This function creates a new object resulting from the overload of the settings (from settings.default) with the settings value (from settings.json) and returns its content.

get(flatKey)

• parameters: flatKey (String) representing the key with : separator access. For instance, if you have an object like: {server:{port:80}} you will access to port by supplying the string server:port to the get function.
• returns: only the value of the targeted key. Could be a JSON, a number or a String.
• description: This function converts the string you provide into a path allowing to access deeply to the JSON. If the value key exist it will returns the value, else undefined.

getMeta(media)

• parameters: media (Object)
• returns: meta (Object)
• description: This function creates a new object resulting from the overload of the media.meta (from settings) with the media.meta (from media parameter) and returns its content.

Working all together with different settings

On your project, you may have other developers working with different settings.
Pushing them in the repo is annoying. We know you've seen that before.
Using standard-settings, developers can share common default settings, AND load custom settings.

Best practice is to add settings/settings.default.json in your repo, this file covers default settings, common for each developer.
And .gitignore settings/settings.json, this file has custom settings inside.

Schema example for a setting file

The following schema is an example of settings used in Soixante circuits apps:

{
  "server": {
      "host" : "myip",
      "port" : 3333
  },
  "timeout": {
    "lookbook": 5,
    "popup": 4
  },
  "folder": {
    "kcDownloader": "path-to/data",
    "lookbook": "path-to/lookbook"
  },
  "flag": {
    "stabalize": true,
    "devMode": true
  },
  "customKey": {
    "maxImageNumber": 64
  },
  "meta": {
      "title": "",
      "description": "",
      "message": "...",
      "source": ""
  },
  "service": {
    "altruist": {
      "host" : "192.168.1.6",
      "port" : 6666
    },
    "spacebro": {
      "host" : "192.168.1.6",
      "port" : 8888,
      "channel": "my-channel",
      "client" : "my-app",
      "inputMessage": "new-media",
      "outputMessage": "new-media-processed"
    }
  }
}

See soixantecircuits/standard

📦 Dependencies

standard-settings depends on:

• nconf
• assignment

🕳 Troubleshooting

• Why my settings don't match my JSON setting file?

A common trap is to forgot that your settings/ folder contains settings.json and settings.default.json. Make sure what are the settings file you have in your app.

• Why my settings are undefined ?

If standard-settings can't find any settings.jsonor settings.default.json, a warning will output to the console. You should look for the sentence: Settings not found.

❤️ Contribute

Please do!