simple.transform v0.0.3

simple.transform

Transform any object Functionally -- a deep recursive JavaScript object transformer.

Require

const {transformObject, transformArray} = require(`simple.transform`);
// Or if you only use transform -- transform() is an alias of transformObject()
const {transform} = require(`simple.transform`);

Use Case

Assume you get a big JSON object to modify for some specific properties to change structure(e.g. for all keys called SPEC_ID no matter how deeply nested, change original stucture {SPEC_ID:"007"} into {SPEC_ID:{value:007}} or {deprecated:{SPEC_ID:007}}).

Design

simple.transform offers two simple API transformObject(input, fn, ...rest) and transformArray(input, fn, ...rest) that recursively process the input object (it simply returns input if that is not in type object) and feed every single objectinto fn for transformObject() and every single Array into fn for transformArray().

So, you can safely assume the first input of fn is always a valid object or Array when you are writing fn -- which is a simple pattern matching transform function.

The only limitation for fn in transformObject() is that must return an object, as its return is passed into lodash.merge() as source.

Detailed Example

NOTE Again, transform() is just an alias of transformObject().

• e.g. Change all SPEC_ID properties from format {SPEC_ID:"007"} into {SPEC_ID:{value:007}}.

const TRANSFORMED = transform(SOURCE_OBJECT, obj => obj.SPEC_ID ? {SPEC_ID:{value:obj.SPEC_ID}} : obj);

• e.g. Change all SPEC_ID properties from format {SPEC_ID:"007"} into {deprecated:{SPEC_ID:007}}, if {deprecated} is an existing property with value in object, the change will merge into the existing object.

const TRANSFORMED = transformObject(SOURCE_OBJECT, obj => obj.SPEC_ID ? {deprecated:{SPEC_ID:obj.SPEC_ID}} : obj);

• e.g. Remove all SPEC_ID properties from format {SPEC_ID:"007"}.

const TRANSFORMED = transformObject(SOURCE_OBJECT, obj => obj.SPEC_ID && typeof obj.SPEC_ID === 'string' ? {} : obj);
// OR
const TRANSFORMED = transformObject(SOURCE_OBJECT, obj => obj.SPEC_ID && typeof obj.SPEC_ID === 'string' ? undefined : obj);

• e.g. Change all SPEC_ID properties from format {SPEC_ID:"007"} into {SPEC_ID:[7]}

const TRANSFORMED = transformObject(SOURCE_OBJECT, obj => obj.SPEC_ID ? {SPEC_ID:[parseInt(obj.SPEC_ID)]} : obj);

• Array example - e.g. Change all array in format ["key1", "key2", ...] into [{value:"key1"}, {value:"key2"}, ...]

const TRANSFORMED = transformArray(SOURCE_OBJECT, arr => arr.length && typeof arr[0] === 'string' ? arr.map(x => ({value:x})) : arr);

More examples can be found in test.js.

Lisense

Licensed under MIT Copyright (c) 2017 Phoenix Song