Merge complex multidimensionnal array

Question

In Javascript, I created a multidimensionnal array, but for another purpose, I need to convert it.

So my array is like this

array [
  0 => {
    "ulStatic": [
      0 => {
        "day": "2019-03-30 18:30:00"
        "id": "7"
        "origin": "intentions"
      }
    ]
    "ulDynamic": [
      0 => {
        "day": "2019-03-30 18:30:00"
        "id": "275"
        "origin": "obs"
      }
    ]
    "ulCreatedDynamic": []
  }
  1 => {
    "ulStatic": [
      0 => {
        "day": "2019-03-31 09:30:00"
        "id": "8"
        "origin": "intentions"
      }
    ]
    "ulDynamic": []
    "ulCreatedDynamic": []
  }
  2 => {
    "ulStatic": []
    "ulDynamic": []
    "ulCreatedDynamic": [
      0 => {
        "day": "2019-04-03 19:30:00"
        "id": "277"
        "origin": "obs"
      }
    ]
  }
]

And I'm trying to have this array :

array [
  0 => {
    "day": "2019-03-30 18:30:00"
    "elements": [
      0 => {
        "id": "7"
        "origin": "intentions"
      }
      1 => {
        "id": "275"
        "origin": "obs"
      }
    ]
  }
  1 => {
    "day": "2019-03-31 09:30:00"
    "elements": [
      0 => {
        "id": "8"
        "origin": "intentions"
      }
    ]
  }
  2 => {
    "day": "2019-04-03 19:30:00"
    "elements": [
      0 => {
        "id": "277"
        "origin": "obs"
      }
    ]
  }
]

And I must admit that I do not know where to start. I'm looking for map(), splice(), concat(), but it's confusing for me. Can you help me to give some advices to achieve that ?

Thank you

Answer 1

grouping the input by day with reduce and return the object values.

const inputAry = [{
    "ulStatic": [{
      "day": "2019-03-30 18:30:00",
      "id": "7",
      "origin": "intentions"
    }],
    "ulDynamic": [{
      "day": "2019-03-30 18:30:00",
      "id": "275",
      "origin": "obs"
    }],
    "ulCreatedDynamic": []
  },
  {
    "ulStatic": [{
      "day": "2019-03-31 09:30:00",
      "id": "8",
      "origin": "intentions",
    }],
    "ulDynamic": [],
    "ulCreatedDynamic": []
  },
  {
    "ulStatic": [],
    "ulDynamic": [],
    "ulCreatedDynamic": [{
      "day": "2019-04-03 19:30:00",
      "id": "277",
      "origin": "obs"
    }]
  }
];


const groupByDay = inputAry.reduce((group, statics) => {
  // flattens the statics array
  [].concat.apply([], Object.values(statics))
    .forEach(({
      day,
      id,
      origin
    }) => {
      // creates a dictionary entry with day as key, if already exist use the existing one or creates a new entry
      group[day] = group[day] || {
        day,
        elements: []
      };

      // push the id and origin to elements
      group[day].elements.push({
        id,
        origin
      });
    });

  return group;
}, {});

const expectedResult = Object.values(groupByDay);

console.log(expectedResult);

Answer 2

    let originalArr = [{
    ulStatic: [
      {
        day: '2019-03-30 18:30:00',
        id: '7',
        origin: 'intentions'
      }
    ],
    ulDynamic: [
      {
        day: '2019-03-30 18:30:00',
        id: '275',
        origin: 'obs'
      }
    ],
    ulCreatedDynamic: []},{ulStatic: [
      {
        day: '2019-03-31 09:30:00',
        id: '8',
        origin: 'intentions'
      }
    ],
    ulDynamic: [],
    ulCreatedDynamic: []},{ ulStatic: [],
    ulDynamic: [],
    ulCreatedDynamic: [
      {
        day: '2019-04-03 19:30:00',
        id: '277',
        origin: 'obs'
      }
    ]}];
    
let op = originalArr.map(item => {
  let ulStatic = item.ulStatic.map(ul => {
    return {
      id: ul.id,
      origin: ul.origin
    };
  });

  let ulDynamic = item.ulDynamic.map(ul => {
    return {
      id: ul.id,
      origin: ul.origin
    };
  });

  let ulCreatedDynamic = item.ulCreatedDynamic.map(ul => {
    return {
      id: ul.id,
      origin: ul.origin
    };
  });

  let day;
  if (ulStatic.length > 0) {
    day = item.ulStatic[0].day;
  } else if (ulDynamic.length > 0) {
    day = item.ulDynamic[0].day;
  } else if (ulCreatedDynamic.length > 0) {
    day = item.ulCreatedDynamic[0].day;
  }
  return {
    day: day,
    elements: [].concat(ulStatic).concat(ulDynamic)
  };
});

console.log(op);

Check this out

Answer 3

You could group your data by day by iterating the values of the value of the objects and their array.

var array = [{ ulStatic: [{ day: "2019-03-30 18:30:00", id: "7", origin: "intentions" }], ulDynamic: [{ day: "2019-03-30 18:30:00", id: "275", origin: "obs" }], ulCreatedDynamic: [] }, { ulStatic: [{ day: "2019-03-31 09:30:00", id: "8", origin: "intentions" }], ulDynamic: [], ulCreatedDynamic: [] }, { ulStatic: [], ulDynamic: [], ulCreatedDynamic: [{ day: "2019-04-03 19:30:00", id: "277", origin: "obs" }] }],
    result = array.reduce((r, o) => {
        Object
            .values(o)
            .forEach(a => a.forEach(({ day, id, origin }) => {
                var temp = r.find(p => day === p.day);
                if (!temp) r.push(temp = { day, elements: [] });
                temp.elements.push({ id, origin });
            }));
        return r;
    }, []);

console.log(result);

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