| # json-schema-traverse |
| Traverse JSON Schema passing each schema object to callback |
| |
| [](https://travis-ci.org/epoberezkin/json-schema-traverse) |
| [](https://www.npmjs.com/package/json-schema-traverse) |
| [](https://coveralls.io/github/epoberezkin/json-schema-traverse?branch=master) |
| |
| |
| ## Install |
| |
| ``` |
| npm install json-schema-traverse |
| ``` |
| |
| |
| ## Usage |
| |
| ```javascript |
| const traverse = require('json-schema-traverse'); |
| const schema = { |
| properties: { |
| foo: {type: 'string'}, |
| bar: {type: 'integer'} |
| } |
| }; |
| |
| traverse(schema, {cb}); |
| // cb is called 3 times with: |
| // 1. root schema |
| // 2. {type: 'string'} |
| // 3. {type: 'integer'} |
| |
| // Or: |
| |
| traverse(schema, {cb: {pre, post}}); |
| // pre is called 3 times with: |
| // 1. root schema |
| // 2. {type: 'string'} |
| // 3. {type: 'integer'} |
| // |
| // post is called 3 times with: |
| // 1. {type: 'string'} |
| // 2. {type: 'integer'} |
| // 3. root schema |
| |
| ``` |
| |
| Callback 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. |
| |
| Callback is passed these parameters: |
| |
| - _schema_: the current schema object |
| - _JSON pointer_: from the root schema to the current schema object |
| - _root schema_: the schema passed to `traverse` object |
| - _parent JSON pointer_: from the root schema to the parent schema object (see below) |
| - _parent keyword_: the keyword inside which this schema appears (e.g. `properties`, `anyOf`, etc.) |
| - _parent schema_: not necessarily parent object/array; in the example above the parent schema for `{type: 'string'}` is the root schema |
| - _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'` |
| |
| |
| ## Traverse objects in all unknown keywords |
| |
| ```javascript |
| const traverse = require('json-schema-traverse'); |
| const schema = { |
| mySchema: { |
| minimum: 1, |
| maximum: 2 |
| } |
| }; |
| |
| traverse(schema, {allKeys: true, cb}); |
| // cb is called 2 times with: |
| // 1. root schema |
| // 2. mySchema |
| ``` |
| |
| Without option `allKeys: true` callback will be called only with root schema. |
| |
| |
| ## License |
| |
| [MIT](https://github.com/epoberezkin/json-schema-traverse/blob/master/LICENSE) |