Merging Linked Data In Array In Javascript

I have a simple task of rearranging a couple of Arrays in a JSON, so ractive.js can handle it better. But I got carried away a bit, and the outcome was not particularly satisfactor

Solution 1:

Construct a map department_id => department_name first:

let departments = {};

for (let x of data) {
    if (x.type === 'department') {
        departments[x._id] = x.Name;
    }
}

Then, iterate over Persons and populate Readable arrays from that map:

for (let x of data) {
    if (x.type === 'person') {
        x.Readable = x.WorksFor.map(w => departments[w]);
    }
}

Finally, extract Persons for the specific Department:

personsInSales = data.filter(x => 
    x.type === 'person' && x.WorksFor.includes('3'));

Solution 2:

Firstly, your data structure does not have a good design. You should not be returning person and department in the same array. If possible, try to redesign the initial data structure to make it more modular, by separating out the people and department into separate structures. However if you are stuck with this same data structure, you can write the code a little better. Please find the code below. Hope it helps!

function mapPeopleDepartment() {
    var deptMap = {},peopleList = [];
    //Iterate through the initialArray and separate out the department into a hashmap deptMap and people into a new peopleList
    for(var i=0; i < initArray.length; i++) {
        var obj = initArray[i];
        obj.type == "department" ? deptMap[obj._id] = obj.Name :  peopleList.push(obj);
     }
    //Iterate through the peopleList to map the WorksFor array to a Readable array
    for(var i=0; i < peopleList.length; i++) {
       var person = peopleList[i];
       person.Readable = _.map(person.WorksFor, function(dept){return deptMap[dept]});
    }
    return peopleList;
}