Duplicate GroupBy Object Array Javascript

Question

I have an input:

var modbusData = [
  { Type: "rtu", Mode: "master", IdDevice: "1", Time: "11:01:00", Data: "1,12,23" },
  { Type: "tcp", Mode: "client", IdDevice: "2", Time: "11:01:11", Data: "30,40,50" },
  { Type: "rtu", Mode: "slave", IdDevice: "1", Time: "11:02:00", Data: "5,10,21" },
  { Type: "tcp", Mode: "server", IdDevice: "2", Time: "11:02:11", Data: "32,44,53" },
];

After I call a funciton for grouping input following Type:

function groupBy(objectArray, property, expectedGroups = []) {
  return objectArray.reduce(function (acc, obj) {
    let key = obj[property]
    if (!acc[key]) {
      acc[key] = []
    }
    acc[key].push(obj)
    return acc
  }, Object.fromEntries(expectedGroups.map(k => [k, []])))
};
const groupedData = groupBy(modbusData, 'Type', [ 'rtu', 'tcp' ]);
console.log(groupedData);

The result will be:

{
  rtu: [
    { Type: 'rtu', Mode: 'master', IdDevice: '1', Time: '11:01:00', Data: '1,12,23' },
    { Type: 'rtu', Mode: 'slave', IdDevice: '1', Time: '11:02:00', Data: '5,10,21' }
  ],
  tcp: [
    { Type: 'tcp', Mode: 'client', IdDevice: '2', Time: '11:01:11', Data: '30,40,50' },
    { Type: 'tcp', Mode: 'server', IdDevice: '2', Time: '11:02:11', Data: '32,44,53' }
  ]
}

And now I want a duplicate GroupBy with Mode, especially when Any Mode is not exist, they will return empty array, which result would be:

{
  rtu: {
    master: [{ Type: 'rtu', Mode: 'master', IdDevice: '1', Time: '11:01:00', Data: '1,12,23' }],
    slave: [{ Type: 'rtu', Mode: 'slave', IdDevice: '1', Time: '11:02:00', Data: '5,10,21' }]
  },
  tcp: {
    client: [{ Type: 'tcp', Mode: 'client', IdDevice: '2', Time: '11:01:11', Data: '30,40,50' }],
    server: [{ Type: 'tcp', Mode: 'server', IdDevice: '2', Time: '11:02:11', Data: '32,44,53' }]
  }
}

Edit1: SubRequest: when input:

var modbusData = [
  { Type: "rtu", Mode: "master", IdDevice: "1", Time: "11:01:00", Data: "1,12,23" },
  { Type: "tcp", Mode: "client", IdDevice: "2", Time: "11:01:11", Data: "30,40,50" },
];

I want output also contain Mode slave and server in empty array like this:

{
  rtu: {
    master: [{ Type: 'rtu', Mode: 'master', IdDevice: '1', Time: '11:01:00', Data: '1,12,23' }],
    slave: []
  },
  tcp: {
    client: [{ Type: 'tcp', Mode: 'client', IdDevice: '2', Time: '11:01:11', Data: '30,40,50' }],
    server: []
  }
}

Jamiec · Accepted Answer · 2021-06-17 09:59:06Z

1

You could put an extra step on the end re-using your groupBy method and making use of Object.entries and Object.fromEntries:

const subGroupedData = Object.fromEntries(Object.entries(groupedData)
    .map( ([key,values]) => ([key, groupBy(values,'Mode')])))

Live example:

var modbusData = [
  { Type: "rtu", Mode: "master", IdDevice: "1", Time: "11:01:00", Data: "1,12,23" },
  { Type: "tcp", Mode: "client", IdDevice: "2", Time: "11:01:11", Data: "30,40,50" },
  //{ Type: "rtu", Mode: "slave", IdDevice: "1", Time: "11:02:00", Data: "5,10,21" },
  //{ Type: "tcp", Mode: "server", IdDevice: "2", Time: "11:02:11", Data: "32,44,53" },
];

function groupBy(objectArray, property, expectedGroups = []) {
  return objectArray.reduce(function (acc, obj) {
    let key = obj[property]
    if (!acc[key]) {
      acc[key] = []
    }
    acc[key].push(obj)
    return acc
  }, Object.fromEntries(expectedGroups.map(k => [k, []])))
};
const groupedData = groupBy(modbusData, 'Type', [ 'rtu', 'tcp' ]);

const expectedSubGroups = {rtu: ['master','slave'], tcp:['client','server']}

const subGroupedData = Object.fromEntries(Object.entries(groupedData)
        .map( ([key,values]) => ([key, groupBy(values,'Mode', expectedSubGroups[key])])))

console.log(subGroupedData);

edited Jun 17, 2021 at 9:59

answered Jun 17, 2021 at 9:29

Jamiec

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3 Comments

CS No.1 Over a year ago

I want an extra request: when Mode: "master" or "slave" not exist in Type : "rtu", as well as "client", "server" of "tcp". They will return empty array

Jamiec Over a year ago

@CSNo.1 Sorry, its not clear from your example what you want. Include in the question an input and output for which you would expect an empty array

Jamiec Over a year ago

@CSNo.1 does this now answer your question?

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