1# json-schema-traverse
2Traverse JSON Schema passing each schema object to callback
3
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7
8
9## Install
10
11```
12npm install json-schema-traverse
13```
14
15
16## Usage
17
18```javascript
19const traverse = require('json-schema-traverse');
20const schema = {
21  properties: {
22    foo: {type: 'string'},
23    bar: {type: 'integer'}
24  }
25};
26
27traverse(schema, {cb});
28// cb is called 3 times with:
29// 1. root schema
30// 2. {type: 'string'}
31// 3. {type: 'integer'}
32
33// Or:
34
35traverse(schema, {cb: {pre, post}});
36// pre is called 3 times with:
37// 1. root schema
38// 2. {type: 'string'}
39// 3. {type: 'integer'}
40//
41// post is called 3 times with:
42// 1. {type: 'string'}
43// 2. {type: 'integer'}
44// 3. root schema
45
46```
47
48Callback function `cb` is called for each schema object (not including draft-06 boolean schemas), including the root schema, in pre-order traversal. Schema references ($ref) are not resolved, they are passed as is.  Alternatively, you can pass a `{pre, post}` object as `cb`, and then `pre` will be called before traversing child elements, and `post` will be called after all child elements have been traversed.
49
50Callback is passed these parameters:
51
52- _schema_: the current schema object
53- _JSON pointer_: from the root schema to the current schema object
54- _root schema_: the schema passed to `traverse` object
55- _parent JSON pointer_: from the root schema to the parent schema object (see below)
56- _parent keyword_: the keyword inside which this schema appears (e.g. `properties`, `anyOf`, etc.)
57- _parent schema_: not necessarily parent object/array; in the example above the parent schema for `{type: 'string'}` is the root schema
58- _index/property_: index or property name in the array/object containing multiple schemas; in the example above for `{type: 'string'}` the property name is `'foo'`
59
60
61## Traverse objects in all unknown keywords
62
63```javascript
64const traverse = require('json-schema-traverse');
65const schema = {
66  mySchema: {
67    minimum: 1,
68    maximum: 2
69  }
70};
71
72traverse(schema, {allKeys: true, cb});
73// cb is called 2 times with:
74// 1. root schema
75// 2. mySchema
76```
77
78Without option `allKeys: true` callback will be called only with root schema.
79
80
81## License
82
83[MIT](https://github.com/epoberezkin/json-schema-traverse/blob/master/LICENSE)
84