Extended JSON - pluggable JSON logic for dates, includes, and more
npm install esonExtended JSON for node.
``
$ npm install eson
Currently only the parser portion is implemented, useful for configuration files.
For example a typical configuration file might look something like the following:
`js`
{
"views": "/www/example.com/views",
"view engine": "jade",
"poll interval": 5000,
"canvas size": { "width": 800, "height": 600 }
}
With Extended JSON you can define plugin functions, or use ones
bundled with eson to transform the input, allowing for more
declarative configurations as shown here:
`js`
{
"views": "{root}/views",
"view engine": "jade",
"poll interval": "5 seconds",
"canvas size": "800x600"
}
Writing a plugin is simple, it's a function which takes the signature (key, val, parser). Let's write one that transforms every value to "foo":
`js`
function foo(key, val, parser) {
return 'foo';
}
Then use the plugin like so:
`js
var eson = require('eson');
var conf = eson()
.use(foo)
.read('path/to/config.json');
`
Now suppose path/to/config.json contained { "foo": "bar", "bar": "baz" },foo()
the plugin would yield { "foo": "foo", "bar": "foo" }. So you get the picture,5000
with this we can accept arbitrary strings such as "5 seconds" and transform
it to the more useful milliseconds representation.
Many plugins may of course be used, and _all_ will be executed regardless, so if necessary
subsequent plugins may still make modifications. Depending on what the plugins the order used _may_ have an effect on the JSON.
`js`
eson()
.use(eson.ms)
.use(eson.include)
.use(eson.dimensions)
.use(eson.replace('{root}', '/www/example.com'))
.parse('{ "interval": "15 minutes" }');$3
The milliseconds plugin supports strings like "5s", "5 seconds", "3 days", etc:
`js`
eson()
.use(eson.ms)
.parse('{ "interval": "15 minutes" }');
yields:
`js`
{ interval: 900000 }
The include plugin allows you to literally include other JSON files. This works in
both arrays and object literals, and loads relative to the callee's file. For example:
`js`
eson()
.use(eson.include)
.parse('{ "prod": "include config/production" }');
yields:
`js`
{ prod: { whatever: 'is', within: 'config/production.json' }}
You can also include multiple files via a glob. This has a special syntax and works in one of three ways.
Consider a config folder containing the following two files:
database.json:
`json`
{"db", "redis"}
app.json:json`
{"listen", 3000}
##### Merging multiple files into one:
`js
eson()
.use(eson.include)
.parse('{ "prod": "include config/*" }');
`
yields:
`js`
{
prod: {
db: "redis",
listen: 3000
}
}
##### Collect files into a map, keyed by filename:
`js
// use curly brackets to collect as a map
eson()
.use(eson.include)
.parse('{ "prod": "include { config/* }" }');
`
yields:
`js
{
prod: {
database: {
db: "redis"
},
app: {
listen: 3000
}
}
}
`
##### Collect files as an array:
`js
// use square brackets to collect as an array
eson()
.use(eson.include)
.parse('{ "prod": "include [ config/* ]" }');
`
yields:
`js`
{
prod: [
{db: "redis"},
{listen: 3000}
]
}
Convert "yes", "no", "on", "off", "enabled", "disabled" into booleans.
Allow environment variables to define config values. If you have the following:
`js`
{
"upload path": "/data/uploads"
}
You could then export UPLOAD_PATH=/tmp to change this value. Optionally whenprefix
a is given such as "MYAPP_" then you must prefix such as MYAPP_UPLOAD_PATH=/tmp.
The replace plugin allows you to replace arbitrary substrings, useful
for constants such as the application's root directory etc.
`js`
eson()
.use(eson.replace('{root}', '/www/example.com'))
.parse('{ "upload path": "{root}/tmp" }');
yields:
`js`
{ "upload path": "/www/example.com/tmp" }
Parse from the given args or __ARGV__. For example if you have a settingfalse
named "dev ui" with a default value of , --dev-ui would enable it,--dev-ui yes
or would provide the value "yes" which is of course also truthy.
To compliment --NAME you may also negate this, if "dev ui" is enabled by default--no-dev-ui
then you may use to disable it.
The glob plugin allows you to specify glob strings, prefixed by "glob":
`js`
eson()
.use(eson.glob)
.parse('{ "js": "glob public/{js,vendor}/*.js" }');
yields:
`js`
{ js: ["public/js/app.js", "public/js/user.js", "public/vendor/jquery.js"] }
That's it for now, just experimenting with it, feel free to send me a PR
or open and issue if you have some ideas. I'd like to keep everything
valid JSON, for example you can use the include plugin to include
env-specific config into package.json, and package.json remains a
valid JSON document.
For addition documentation view the test markdown.
`
$ npm install
$ make test
(The MIT License)
Copyright (c) 2012 TJ Holowaychuk <tj@vision-media.ca>
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permit persons to whom the Software is furnished to do so, subject to
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