objer

Description

This package is used to interact with objects

Basic Usage

install

npm install --save objer

import

import { get, set, has } from 'objer';

Api Reference

get(object, path, defaultValue)

Important note, null path is treated abnormally, if you need something more traditional use yank

parameters:

• object: The object to get a value from
• path: The key path to pull the value from
  • This can be a string 'a.b.c' or an array ['a', 'b', 'c'] or null, if the key is null object is returned
• defaultValue: If there is no value at that location, (if that value comes out as undefined), get will return this value. If this value is not specified get will return undefined

response:

The value at that key

example:

const person = {
    name: 'jeffery',
    address: {
        street: '123 fake st',
        city: 'faketown',
        state: 'FS',
        zip: '90909',
    }
};

get(person, 'address.city'); // returns 'faketown'
get(person, ['address', 'city']); // returns 'faketown'
get(person, 'key.that.doesnot.exist'); // returns undefined
get(person, 'key.that.doesnot.exist', 'hola'); // returns 'hola'
get(person, null, 'hola'); // returns whole person object

yank(object, path, defaultValue)

parameters:

• object: The object to get a value from
• path: The key path to pull the value from
  • This can be a string 'a.b.c' or an array ['a', 'b', 'c'] or a number, if the path is any other type the default value will be returned
• defaultValue: If there is no value at that location, (if that value comes out as undefined), get will return this value. If this value is not specified get will return undefined

response:

The value at that key

example:

const person = {
    name: 'jeffery',
    address: {
        street: '123 fake st',
        city: 'faketown',
        state: 'FS',
        zip: '90909',
    }
};

yank(person, 'address.city'); // returns 'faketown'
yank(person, ['address', 'city']); // returns 'faketown'
yank(person, 'key.that.doesnot.exist'); // returns undefined
yank(person, 'key.that.doesnot.exist', 'hola'); // returns 'hola'
yank(person, null, 'hola'); // returns 'hola'

firstValue(object)

parameters:

• object: The object or array to get a value from

response:

The first value in the object or array

example:

const person = {
    name: 'jeffery',
    address: {
        street: '123 fake st',
        city: 'faketown',
        state: 'FS',
        zip: '90909',
    },
    things: [5, 9, 0],
};

firstValue(person); // returns 'jeffery'
firstValue(person.things); // returns 5

firstKey(object)

parameters:

• object: The object or array to get a key from

response:

The first key in the object or array

example:

const person = {
    name: 'jeffery',
    address: {
        street: '123 fake st',
        city: 'faketown',
        state: 'FS',
        zip: '90909',
    },
    things: [5, 9, 0],
};

firstKey(person); // returns 'name'
firstKey(person.things); // returns 0

has(object, path)

parameters:

• object: The object to get a value from
• path: The key path to check for existence
  • This can be a string 'a.b.c' or an array ['a', 'b', 'c'] or null, if the key is null object is returned

response:

true|false

example:

const person = {
    name: 'jeffery',
    address: {
        street: '123 fake st',
        city: 'faketown',
        state: 'FS',
        zip: '90909',
    }
};

has(person, 'address'); // returns true
has(person, 'address.city'); // returns true
has(person, ['address', 'city']); // returns true
has(person, 'key.that.doesnot.exist'); // returns false
has(person, 'key.that.really.doesnot.exist'); // returns false

set(object, path, value)

parameters:

• object: The object to get a value from
• path: The key path to pull the value from
  • This can be a string 'a.b.c' or an array ['a', 'b', 'c'] or null, if the key is null object is returned
• value: Set the value of subkey inside object to value

response:

object: the original object passed into set

example:

const person = {
    name: 'jeffery',
    address: {
        street: '123 fake st',
        city: 'faketown',
        state: 'FS',
        zip: '90909',
    }
};

set(person, ['address', 'country'], 'United States'); // returns person, person.address.country is now equal to 'United States'
set(person, ['address', 'city'], 'realtown'); // returns person, person.address.realtown is changed to 'realtown'

keys(object)

parameters:

• object: The object to get a list of keys from, passing an array returns an array of indexes with each index a string

response:

array of keys

example:

const person = {
    name: 'jeffery',
    address: {
        street: '123 fake st',
        city: 'faketown',
        state: 'FS',
        zip: '90909',
    }
};

keys(person); // returns ['name', 'address']
keys(person.address); // returns ['street', 'city', 'state', 'zip']

values(object)

parameters:

• object: The object to get a list of values from

response:

array of values

example:

const person = {
    name: 'jeffery',
    address: {
        street: '123 fake st',
        city: 'faketown',
        state: 'FS',
        zip: '90909',
    }
};

values(person); // returns ['jeffery', { street: '123 fake st', city: 'faketown', state: 'FS', zip: '90909' }]
values(person.address); // returns ['123 fake st', 'faketown', 'FS', '90909']

pick(object, whitelistedKeys)

parameters:

• object: The object to get a list of values from
• whitelistedKeys: An array of keys to pick from the original object, can be deep values such as a.b.c.e[5]

response:

new object filled with matching whitelistedKeys keys from object

example:

const person = {
    name: 'jeffery',
    address: {
        street: '123 fake st',
        city: 'faketown',
        state: 'FS',
        zip: '90909',
    }
};

pick(person, ['address.street']); // returns { address: { street: '123 fake st' } }
pick(person, ['address.street', 'address.state']); // returns { address: { street: '123 fake st', state: 'FS' } }
pick(person, ['name']); // returns { name: 'jeffery' }

getObjectPath(path)

parameters:

• path: The path to retrieve a path array from

response:

array of keys representing path

example:

getObjectPath('a.b.c'); // returns ['a', 'b', 'c']
getObjectPath(['a', 'b', 'c']); // returns ['a', 'b', 'c']
getObjectPath(['a', 'b.c']); // returns ['a', 'b.c']
getObjectPath('a[1].b'); // returns ['a', 1, 'b']
getObjectPath('a.1.b'); // returns ['a', '1', 'b']

getStringPathForArray(pathArray)

parameters:

• pathArray: The path array to retrieve a path string from

response:

string representing the path

example:

getObjectPath(['a', 'b', 'c']); // returns 'a.b.c'
getObjectPath(['a', 1, 'c']); // returns 'a[1].c'
getObjectPath('a[1].c'); // returns 'a[1].c'

getTypeString(entity)

parameters:

• entity: Anything

response:

string representing the type

example:

getTypeString(''); // returns 'string'
getTypeString(1); // returns 'number'
getTypeString(1.5); // returns 'number'
getTypeString({}); // returns 'object'
getTypeString([]); // returns 'array'
getTypeString((() => {})); // returns 'function'
getTypeString(true); // returns 'boolean'
getTypeString(null); // returns 'null'
getTypeString(undefined); // returns 'undefined'
getTypeString(NaN); // returns 'number'
getTypeString(Infinity); // returns 'number'
getTypeString(new Date()); // returns 'date'
getTypeString(/hello/g); // returns 'regexp'
class test {}
getTypeString(new test()); // returns 'object'
getTypeString(Symbol(55)); // returns 'symbol'
getTypeString(new Promise((() => {}))); // returns 'promise'
getTypeString(new String('')); // returns 'string'

deepEq(item1, item2)

parameters:

• item1: Anything
• item2: Anything

response:

Checks for direct equality, and in the case of objects and arrays checks for subkey equality note: does not handle class instance equality

example:

deepEq([{ first: 'bobabob', second: 'gogagog' }], [{ second: 'gogagog', first: 'bobabob' }]); // returns true
deepEq({ first: 1 }, { first: 2 }); // returns false

partition(list, paritionFunctionObject, defaultKey)

parameters:

• list: Original list to partition, array
• partitionFunctionObject: Takes an object where the key is the partition key, and the value is a function that returns a boolean indicating whether or not a given line item passed the condition to be added to that partition
• defaultKey: If the list item does not pass any of the partitionFunctionObject function tests, it will be assigned to the default key, if the default key is null the line item is ignored

response:

An object that contains the same keys the partitionFunctionObject + the default key, the values are the list of line items that passed the conditions in the partition functions

example:

const original = [1, 2, 3, 4, 5];

partition(original, { even: item => item % 2 === 0 }, 'odd'); // returns { even: [2, 4], odd: [1, 3, 5] }

mapObject(object, modificationFunction)

parameters:

• object: Original object to modify
• modificationFunction: Function to execute on every value of object, the results of this function will be assigned as the new value of the resultant object for the original key
  • (value, key, keyIndex) => any

response:

A new object with all the same keys as the original object with every value the result of the modification function

example:

const original = { a: 1, b: 2, c: 3 };

mapObject(original, item => item + 3); // returns { a: 4, b: 5, c: 6 }