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}
 ]