Groupjs_by NPM

groupjs_by 🚀

groupjs_by is a javascript library for grouping array of objects using attribute name , it support basic operations such as sum, avg, max, min and countDistinct. it support chaning more than one operation.

Installation

Use the package manager to install groupjs_by.

Usage

sum(alias,columnName)

type	Parameters	description
string	alias	alias for the agreggation sum
string	columnName	name of the column to perform the aggregation

example using data :

const data = [
  { category: 'mammals', name: 'lion', weight: 80 },
  { category: 'mammals', name : 'panter', weight: 100 },
  { category : 'reptiles', name : 'cocodrile', weight: 100}
]

const group = require('groupjs_by');
group
.groupBy(data,'category')
.sum('animalsWeight','weight')
.data;

// will return
{
    mammals:{
        items :  [
            { category: 'mammals', name: 'lion', weight: 80 },
            { category: 'mammals', name : 'panter', weight: 100 }
        ],
        animalsWeight: 180
    },
    reptiles: {
        items : [
            { category : 'reptiles', name : cocodrile, weight: 100}
        ],
        animalsWeight: 100
    }
}

min(alias,columnName)

Operation	Parameters	description
string	alias	alias for the agreggation min
string	columnName	name of the column to get the min value

example :

const group = require('groupjs_by');
group.groupBy(data,'category')
.min('minWeight','weight')
.data;

// will return

{
    mammals:{
        items :  [
            { category: 'mammals', name: 'lion', weight: 80 },
            { category: 'mammals', name : 'panter', weight: 100 }
        ]
        minWeight: 80
    },
    reptiles: {
        items : [
            { category : 'reptiles', name : cocodrile, weight: 100}
        ],
        minWeight: 100
    }
}

max(alias,ColumnName)

Operation	Parameters	description
string	alias	alias for the agreggation max
string	columnName	name of the column to get the max value

example :

const group = require('groupjs_by');
group.groupBy(data,'category')
.max('maxWeight','weight')
.data;

// will return

{
    mammals:{
        items :  [
            { category: 'mammals', name: 'lion', weight: 80 },
            { category: 'mammals', name : 'panter', weight: 100 }
        ]
        maxWeight: 100
    },
    reptiles: {
        items : [
            { category : 'reptiles', name : cocodrile, weight: 100}
        ],
        maxWeight: 100
    }
}

avg(alias,columnName,decimals)

Operation	Parameters	description
string	alias	alias for the agreggation avg
string	columnName	name of the column to get to perform the avg
int	decimals	The number of decimals to format the float avg value, by default 2

example :

const group = require('groupjs_by');
group
.groupBy(data,'category')
.avg('avgWeight','weight').data;

// will return

{
    mammals:{
        items :  [
            { category: 'mammals', name: 'lion', weight: 80 },
            { category: 'mammals', name : 'panter', weight: 100 }
        ]
        avgWeight: '90.00'
    },
    reptiles: {
        items : [
            { category : 'reptiles', name : cocodrile, weight: 100}
        ],
        avgWeight: '100.00'
    }
}

distinctCount(alias,columnName)

Operation	Parameters	description
string	alias	alias for the agreggation distinctCount
string	columnName	name of the column to get to perform counting

example :

const group = require('groupjs_by');
group
.groupBy(data,'category')
.distinctCount('distinctAnimals','name')
.data

// will return

{
    mammals:{
        items :  [
            { category: 'mammals', name: 'lion', weight: 80 },
            { category: 'mammals', name : 'panter', weight: 100 }
        ]
        distinctAnimals: 2
    },
    reptiles: {
        items : [
            { category : 'reptiles', name : cocodrile, weight: 100}
        ],
        distinctAnimals: 1
    }
}

Chaining Operations

Chaining operations are supported , it´s possible to chain more than one operation

example :

const group = require('groupjs_by');
const chainedResult =
group
.groupBy(data,'category')
.distinctCount('distinctAnimals','name')
.avg('avgWeight','weight')
.sum('animalsWeight','weight').data

// will return
{
    mammals:{
        items :  [
            { category: 'mammals', name: 'lion', weight: 80 },
            { category: 'mammals', name : 'panter', weight: 100 }
        ]
        distinctAnimals: 2,
        avgWeight: '90.00',
        animalsWeight: 180
    },
    reptiles: {
        items : [
            { category : 'reptiles', name : cocodrile, weight: 100}
        ],
        distinctAnimals: 1,
        avgWeight: '100.00',
        animalsWeight: 100
    }
}

keys

To retrieve the list of keys of which the object is grouped

const group = require('groupjs_by');
group
.groupBy(data,'category')
.keys

// will return an array of keys of grouped data.
 ex:
 ['mammals','reptiles']

firstGroup

Returns the first group of aggregate data , the order its determinaded by the order of data was provided.

const group = require('groupjs_by');
group
.groupBy(data,'category')
.firstGroup

will return

 ex:
 [
     { category: 'mammals', name: 'lion', weight: 80 },
     { category: 'mammals', name : 'panter', weight: 100 }
 ]

lastGroup

Returns the last group of aggregate data , the order its determinaded by the order of data was provided.

const group = require('groupjs_by');
group
.groupBy(data,'category')
.lastGroup

will return

 ex:
 [
     { category : 'reptiles', name : cocodrile, weight: 100}
 ]