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