ahmed3bdallah1/flat

Take a nested Map and flatten it with delimited keys

flat

Take a nested Map and flatten it with delimited keys. Entirely based on node.js flat.

It does not achieve feature parity yet, as some options are missing from flatten (transformKey) and unflatten (object, overwrite, transformKey).

Currently, it bails out of a tree if it finds something different than a Map or List when flatening, or a nested Map or List when unflattening.

Methods

flatten

import 'package:flat/flat.dart';

flatten(
    {
      "a": 1,
      "list1": ["item1", "item2"],
      "f": {
        "list2": ["item3", "item4", "item5"],
        "g": 2,
        "h": true,
        "j": "text",
      },
    },
  );

// {
//   "a": 1,
//   "list1.0": "item1",
//   "list1.1": "item2",
//   "f.list2.0": "item3",
//   "f.list2.1": "item4",
//   "f.list2.2": "item5",
//   "f.g": 2,
//   "f.h": true,
//   "f.j": "text"
// }

delimiter

Use a custom delimiter for flattening your objects, instead of .

safe

When enabled, flat will preserve arrays and their contents. This is disabled by default.

import 'package:flat/flat.dart';

flatten({
  'this': [
    {'contains': 'arrays'},
    {
      'preserving': {'them': 'for you'}
    }
  ]
}, safe: true);

// {
//   'this': [
//     {'contains': 'arrays'},
//     {
//       'preserving': {'them': 'for you'}
//     }
//   ]
// };

maxDepth

Maximum number of nested objects to flatten.

import 'package:flat/flat.dart';

flatten({
  'key1': {'keyA': 'valueI'},
  'key2': {'keyB': 'valueII'},
  'key3': {
    'a': {
      'b': {'c': 2}
    }
  }
}, maxDepth: 2);

// {
//   'key1.keyA': 'valueI',
//   'key2.keyB': 'valueII',
//   'key3.a': {
//     'b': {'c': 2}
//   }
// };

unflatten

Reverse process from flatten.

Only supports completely flat maps as input.

unflatten({
  "a": 1,
  "list1.0": "item1",
  "list1.1": "item2",
  "f.list2.0": "item3",
  "f.list2.1": "item4",
  "f.list2.2": "item5",
  "f.g": 2,
  "f.h": true,
  "f.j": "text"
});

// {
//   "a": 1,
//   "list1": ["item1", "item2"],
//   "f": {
//     "list2": ["item3", "item4", "item5"],
//     "g": 2,
//     "h": true,
//     "j": "text",
//   },
// }

delimiter

Use a custom delimiter for unflattening your objects, instead of .