object-rewrite

Rewrite an Object by defining exactly what gets excluded, rewritten and included.

Install

npm i --save object-rewrite

Getting Started

Modify the data object in place. If you need to create a copy consider using _.deepClone().

const objectRewrite = require("object-rewrite");

const data = [{
  guid: "aad8b948-a3de-4bff-a50f-3d59e9510aa9",
  count: 3,
  active: true,
  tags: [{ id: 1 }, { id: 2 }, { id: 3 }]
}, {
  guid: "4409fb72-36e3-4385-b3da-b4944d028dcb",
  count: 4,
  active: true,
  tags: [{ id: 2 }, { id: 3 }, { id: 4 }]
}, {
  guid: "96067a3c-caa2-4018-bcec-6969a874dad9",
  count: 5,
  active: false,
  tags: [{ id: 3 }, { id: 4 }, { id: 5 }]
}];

const rewriter = objectRewrite({
  exclude: {
    "": (key, value) => value.active !== true,
    tags: (key, value) => value.id !== 4
  },
  inject: {
    "": (key, value) => ({ count: value.count + 100 })
  },
  include: ["count", "active", "tags.id"]
});

rewriter(data);

// => data is now modified
/*
[{
  "count": 103,
  "active": true,
  "tags": []
}, {
  "count": 104,
  "active": true,
  "tags": [{"id": 4}]
}]
*/

The empty needle "" matches top level objects when data is an array.

Modifiers

Needles are specified according to object-scan.

Internally the option useArraySelector is set to false.

Functions have signature Fn(key, value, parents) as specified by object-scan. Keys are split (joined = false),

Exclude

Takes object where keys are needles and values are functions. The matches for a needle are excluded from the rewritten object iff the function returns true.

Inject

Takes object where keys are needles and values are functions. The result of the function is merged into every match for the needle. Both, the match and the function response, are expected to be objects.

Include

Array of all fields that are included in the modified object. All entries not matched are excluded.