]>
Commit | Line | Data |
---|---|---|
06a3d686 BB |
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 |