Extremely light weight way to resolve jsonschema '$ref' references & inheritance: create circular/graphs, fractals from json (browser/coffeescript/javascript).

Stop processing json tree-structures, think json references and extentions.

Usage

nodejs:

jref = require('json-ref-parser')

Rule of thumb

When referencing to keys, always use underscores. Not doing this will not resolve references correctly.

Features

| Feature | Notation | |-----------------------------------------------------|------------------------------------------------------------------------| |resolving (old) jsonschema references to 'id'-fields | "$ref": "foobar" | |resolving (new) jsonschema internal jsonpointers | "$ref": "#/foo/value" | |resolving positional jsonpointers | "$ref": "#/foo/bar[2]" | |resolving grouped jsonpointers | "$ref": [{"$ref": "#/foo"},{"$ref": "#/bar}] for building jsongraphs | |evaluating positional jsonpointer function | "$ref": "#/foo/bar()" | |resolving local files | "$ref": "/some/path/test.json" | |resolving remote json(schema) files | "$ref": "http://foo.com/person.json" | |resolving remote jsonpointers | "$ref": "http://foo.com/person.json#/address/street" | |evaluating jsonpointer notation in string | foo_{#/a/graph/value} | |evaluating dot-notation in string | foo_{a.graph.value} |

Developer tools:

| Feature | Howto | |-----------------------------------------------------|------------------------------------------------------------------------| |console.log debug output | jref.debug = true | |redefine ref token | jref.reftoken = '@ref' | |redefine extend token | jref.extendtoken = '@extend' | |redefine jsonpointer starttoken | jref.pathtoken = '#' | |redefine resolve tokens | jref.resolvetoken = '@res'

NOTE: re-defining tokens is useful to prevent resolving only certain references. A possible rule of thumb could be to have '$ref' references for serverside, and '@ref' references for clientside when resolving the same jsondata.

Example: id fields

json = {
  foo: {
    id: 'foobar',
    value: 'bar'
  },
  example: {
    '$ref': 'foobar'
  }
};

outputs:

{
  foo: { id: 'foobar', value: 'bar' },
  example: {
    '$ref': 'foobar',
    '$res': { value: 'bar' }
}

Example: jsonpointers

{
  foo: {
    value: 'bar',
    foo: 'flop'
  },
  example: {
    ids: {
      '$ref': '#/foo/foo'
    }
  }
}

outputs:

{
  foo: {
    value: 'bar',
    foo: 'flop'
  },
  example: {
    ids: {
      '$ref': '#/foo/foo',
      '$res': 'flop'
    }
  }
}

NOTE: escaping slashes in keys is supported. "#/model/foo['\\/bar']/flop" will try to reference model.foo['/bar'].flop from itself

Example: remote schemas

{
  foo: {
    "$ref": "http://json-schema.org/address"
  }
  bar: {
    "$ref": "http://json-schema.org/address#/street/number"
  }
}

outputs: replaces value of foo with jsonresult from given url, also supports jsonpointers to remote source

NOTE: please install like so for remote support: 'npm install json-ref-lite sync-request'

Example: local files

{
  foo: {
    "$ref": "./test.json"
  }
}

outputs: replaces value of foo with contents of file test.json (use './' for current directory).

Example: array references

{
  "bar": ["one","two"],
  "foo": { "$ref": "#/bar[1]" }
}

outputs:

{
  "bar": ["one","two"],
  "foo": {
    "$ref": "#/bar[1]",
    '$res': "two"
  }
}

Example: evaluating functions

Ofcoarse functions fall outside the json scope, but they can be executed after binding them to the json.

json = {
  "bar": { "$ref": "#/foo()" }
}

json.foo = function(){ return "Hello World"; }

outputs:

{
  "bar": {
    "$ref": "#/foo()",
    '$res': "Hello World"
    }
}