📚 json-order

json-order allows for conversion between JS Objects and a JSON string while keeping property order, controlled via a property map. All manner of nesting is supported.

Usage

parse

To parse a JSON string and generate a map:

const result = orderedJson.parse(srcJson, prefix, separator);

Parameters

• srcJson: a json string
• prefix [optional]: a non-empty string that controls what the key prefix value is in the generated map. Defaults to $.
• separator [optional]: a non-empty string that controls what the key separator is in the generated map. Defaults to ~.

result.object will contain a JS object while result.map will contain the generated property map.

stringify

To stringify a JS object maintaining a particular property order:

const jsonString = orderedJson.stringify(srcObj, map, 2);

Parameters

• srcObj: an object with the properties in any order
• map [optional]: the property map generated by parse above. If the map is unset, the response is a standard JSON.stringify.
• separator [optional]: a non-empty string that controls what the key separator is in the generated map. Defaults to ~.
• space [optional]: a number used to insert white space into the output JSON string for readability purposes, as per the JSON.stringify documentation.

order

To duplicate a JS object but containing a particular property order:

const orderedObj = orderedJson.order(srcObj, map, 2);

Parameters

• srcObj: an object with the properties in any order
• map [optional]: the property map generated by parse above. If the map is unset, the response is a standard JSON.stringify.
• separator [optional]: a non-empty string that controls what the key separator is in the generated map. Defaults to ~.

Example

An object with a particular property order:

{
  "z": {
    "y": 5,
    "b": [
      false,
      {
        "d": 3,
        "c": 2
      },
      14
    ]
  },
  "a": "hello"
}

Will generate a lookup object like:

{
  "$": ["z", "a"],
  "$.z": ["y", "b"],
  "$.b.1": ["d", "c"]
}

Why?

JS Objects in JavaScript do keep their property insertion order (this behaviour is dependant on the JS engine), however this behaviour is not guaranteed by other systems you may interchange that object with.

For example, when storing a JS Object in a SQLite database, the returned object will have its properties in alphabetical order. Order in an array is preserved, however order of properties in an object is not.

This behavior is undesirable in certain cases. If a user has configured an application via JSON, they may choose to make logical groupings of properties. When this JSON is parsed to a JS Object, stored in the DB and extracted again, the groupings no longer exist because the properties have been alphabetically ordered.

There are several solutions to this problem, (eg. storing the data in a different format) but this migration process can be tedious and complex in certain use cases.

This particular implementation is in reference to the approach suggested for feature 1046 in Insomnia.

Contributing

Please raise issues or feature requests via the Github issue tracker

Feel free to submit a pull request with your change!

yarn install
yarn test

License

MIT