git.r.bdr.sh - rbdr/dotfiles/blob - atom/packages/pretty-json/node_modules/json-stable-stringify/readme.markdown

   1 # json-stable-stringify
   2
   3 deterministic version of `JSON.stringify()` so you can get a consistent hash
   4 from stringified results
   5
   6 You can also pass in a custom comparison function.
   7
   8 [![browser support](https://ci.testling.com/substack/json-stable-stringify.png)](https://ci.testling.com/substack/json-stable-stringify)
   9
  10 [![build status](https://secure.travis-ci.org/substack/json-stable-stringify.png)](http://travis-ci.org/substack/json-stable-stringify)
  11
  12 # example
  13
  14 ``` js
  15 var stringify = require('json-stable-stringify');
  16 var obj = { c: 8, b: [{z:6,y:5,x:4},7], a: 3 };
  17 console.log(stringify(obj));
  18 ```
  19
  20 output:
  21
  22 ```
  23 {"a":3,"b":[{"x":4,"y":5,"z":6},7],"c":8}
  24 ```
  25
  26 # methods
  27
  28 ``` js
  29 var stringify = require('json-stable-stringify')
  30 ```
  31
  32 ## var str = stringify(obj, opts)
  33
  34 Return a deterministic stringified string `str` from the object `obj`.
  35
  36 ## options
  37
  38 ### cmp
  39
  40 If `opts` is given, you can supply an `opts.cmp` to have a custom comparison
  41 function for object keys. Your function `opts.cmp` is called with these
  42 parameters:
  43
  44 ``` js
  45 opts.cmp({ key: akey, value: avalue }, { key: bkey, value: bvalue })
  46 ```
  47
  48 For example, to sort on the object key names in reverse order you could write:
  49
  50 ``` js
  51 var stringify = require('json-stable-stringify');
  52
  53 var obj = { c: 8, b: [{z:6,y:5,x:4},7], a: 3 };
  54 var s = stringify(obj, function (a, b) {
  55     return a.key < b.key ? 1 : -1;
  56 });
  57 console.log(s);
  58 ```
  59
  60 which results in the output string:
  61
  62 ```
  63 {"c":8,"b":[{"z":6,"y":5,"x":4},7],"a":3}
  64 ```
  65
  66 Or if you wanted to sort on the object values in reverse order, you could write:
  67
  68 ```
  69 var stringify = require('json-stable-stringify');
  70
  71 var obj = { d: 6, c: 5, b: [{z:3,y:2,x:1},9], a: 10 };
  72 var s = stringify(obj, function (a, b) {
  73     return a.value < b.value ? 1 : -1;
  74 });
  75 console.log(s);
  76 ```
  77
  78 which outputs:
  79
  80 ```
  81 {"d":6,"c":5,"b":[{"z":3,"y":2,"x":1},9],"a":10}
  82 ```
  83
  84 ### space
  85
  86 If you specify `opts.space`, it will indent the output for pretty-printing.
  87 Valid values are strings (e.g. `{space: \t}`) or a number of spaces
  88 (`{space: 3}`).
  89
  90 For example:
  91
  92 ```js
  93 var obj = { b: 1, a: { foo: 'bar', and: [1, 2, 3] } };
  94 var s = stringify(obj, { space: '  ' });
  95 console.log(s);
  96 ```
  97
  98 which outputs:
  99
 100 ```
 101 {
 102   "a": {
 103     "and": [
 104       1,
 105       2,
 106       3
 107     ],
 108     "foo": "bar"
 109   },
 110   "b": 1
 111 }
 112 ```
 113
 114 # install
 115
 116 With [npm](https://npmjs.org) do:
 117
 118 ```
 119 npm install json-stable-stringify
 120 ```
 121
 122 # license
 123
 124 MIT