Add %J formatter

README.md

@@ -159,6 +159,8 @@ or at runtime:
 acho.level = 'debug';
 ```
 
+See more at [examples/levels](https://github.com/achohq/acho/blob/master/examples/levels.js).
+
 ### Customization
 
 You can completely customize the library to your requirements: changes colors, add more types, sort the priorities... the internal structure of the object is public and you can edit it dynamically. **You have the power**.
@@ -195,6 +197,52 @@ acho.info('I am hungry');
 
 If you need customize more the output you can setup `.print` `.generateMessage` (see below) that are a more low level methods for generate and print the output message.
 
+## Formatters
+
+We use [printf-style](https://wikipedia.org/wiki/Printf_format_string) formatting. Below are the officially supported formatters:
+
+| Formatter | Representation                                                |
+|-----------|---------------------------------------------------------------|
+| `%s`      | String.                                                       |
+| `%d`      | Number (both integer and float).                              |
+| `%j`      | JSON serialization in one line                                |
+| `%J`      | JSON pretty object in multiple lines                          |
+| `%%`      | Single percent sign ('%'). This does not consume an argument. |
+
+By default, the `%j` is applied when you pass an object to be logged:
+
+```js
+acho.info({hello: 'world', foo: 'bar'})
+// => 'info hello=world foo=bar'
+```
+
+If you want to use a different formatter, use printf markup:
+
+```js
+acho.info('formatting with object interpolation %J', {
+  hello: 'world',
+  foo: 'bar',
+  deep: {
+    foo: 'bar',
+    arr: [1, 2, 3, 4, 5]
+  }
+})
+
+// info formatting with object interpolation
+//  hello: "world"
+//    foo: "bar"
+//   deep:
+//         foo: "bar"
+//         arr:
+//              0: 1
+//              1: 2
+//              2: 3
+//              3: 4
+//              4: 5
+```
+
+See more at [examples/formatter](https://github.com/achohq/acho/blob/master/examples/formatter.js).
+
 ## API
 
 ### Acho({Object} [options])

examples/formatter.js

@@ -0,0 +1,18 @@
+'use strict'
+
+var Acho = require('..')
+var acho = Acho()
+
+acho.info('formatting plain text: hello world')
+acho.info('formatting with number interpolation %d', 123)
+acho.info('formatting with float interpolation %d', 3.14)
+acho.info('formatting with string interpolation %s', 'hello world')
+acho.info('formatting with object interpolation %j', {hello: 'world', foo: 'bar'})
+acho.info('formatting with object interpolation %J', {
+  hello: 'world',
+  foo: 'bar',
+  deep: {
+    foo: 'bar',
+    arr: [1, 2, 3, 4, 5]
+  }
+})

lib/Default.coffee

@@ -152,11 +152,11 @@ module.exports =
       symbol    : CONST.FIGURE.warning
 
     error:
-      level : 1
-      color : 'red'
-      symbol: CONST.FIGURE.error
+      level  : 1
+      color  : 'red'
+      symbol : CONST.FIGURE.error
 
     fatal:
-      level : 0
-      color : 'red'
-      symbol: CONST.FIGURE.error
+      level  : 0
+      color  : 'red'
+      symbol : CONST.FIGURE.error

lib/Format.coffee

@@ -1,20 +1,36 @@
 'use strict'
 
+fmtObj = require 'fmt-obj'
 slice = require 'sliced'
 chalk = require 'chalk'
 
+CONST = require './Constants'
+
 ESCAPE_REGEX = /%{2,2}/g
-TYPE_REGEX = /(%?)(%([jds]))/g
+TYPE_REGEX = /(%?)(%([Jjds]))/g
 
 isString = (obj) -> typeof obj is 'string'
 isSymbol = (obj) -> typeof obj is 'symbol'
 isObject = (obj) -> typeof obj is 'object'
 isFalsy = (value) -> [null, undefined, false].indexOf(value) isnt -1
 isArray = (arr) -> Array.isArray(arr)
-colorize = (value, color) -> chalk[color](value)
 hasWhiteSpace = (s) -> s.indexOf(' ') isnt -1
 
-serialize = (color, obj, key) ->
+colorize = (value, color) -> chalk[color](value)
+
+prettyObj = (obj, color) ->
+  lineColor = chalk[CONST.LINE_COLOR]
+
+  fmtObj(obj, Infinity,
+    punctuation: lineColor
+    annotation: lineColor
+    property: chalk[color]
+    literal: lineColor
+    number: lineColor
+    string: lineColor
+  )
+
+serialize = (obj, color, key) ->
   # symbols cannot be directly casted to strings
   key = key.toString() if isSymbol key
   obj = obj.toString() if isSymbol obj
@@ -38,20 +54,20 @@ serialize = (color, obj, key) ->
     key = keys[i]
     value = obj[key]
 
-    if isArray(value)
+    if isArray value
       msg += key + '=['
       j = 0
       l = value.length
       while j < l
-        msg += serialize(color, value[j])
+        msg += serialize(value[j], color)
         if j < l - 1
           msg += ' '
         j++
       msg += ']'
     else if value instanceof Date
       msg += key + '=' + value
     else
-      msg += serialize(color, value, colorize(key, color))
+      msg += serialize(value, color, colorize(key, color))
     if i < length - 1
       msg += ' '
     i++
@@ -70,14 +86,16 @@ format = (fmt) ->
         when 'd'
           arg = colorize(Number(arg), color)
         when 'j'
-          arg = serialize color, arg
+          arg = serialize arg, color
+        when 'J'
+          arg = prettyObj arg, color
       return arg if !escaped
       args.unshift arg
       match
     )
 
-  fmt += ' ' + serialize color, arg for arg in args if args.length
+  fmt += ' ' + serialize arg, color for arg in args if args.length
   fmt = fmt.replace(ESCAPE_REGEX, '%') if fmt.replace?
-  serialize color, fmt
+  serialize fmt, color
 
 module.exports = format

package.json

@@ -27,6 +27,7 @@
   "dependencies": {
     "chalk": "~1.1.1",
     "coffee-script": "~1.12.4",
+    "fmt-obj": "~1.3.0",
     "pretty-ms": "~2.1.0",
     "sliced": "~1.0.1"
   },