Angular: Combine array objects and combine values - arrays

Question

I'm retrieving data with http.get.
This provides me with an array of objects like below:
[{
"id”:12345,
"resource_state":2,
"external_id”:”abscdgrft”,
"upload_id”:1234567,
"athlete":{
"id”:123456,
"resource_state":2,
"firstname”:”testname”,
"lastname”:”testlastname”,
"profile_medium”:”image/athlete/medium.png",
"profile":"image/athlete/large.png",
"city”:”testcity”,
"state”:”teststate”,
…
},
"name”:”test name“,
"distance":87223.1,
"moving_time":11026,
"elapsed_time":11173,
"total_elevation_gain":682.3,
…
}]
I would like to combine all those object based on the athlete.firstname + athlete.lastname.
So for example all objects with athlete first name Jim and last name Donalds I want to be combined in one object, the same goes for all the other names.
When combining the objects based on the full name, values like "distance", "moving_time", "elapsed_time" and "total_elevation_gain" needs to be summed.
I tried using the code below but the problem is that I can't get it to work with multiple values like I mention above.
This is working only with one value, distance for example:
var obj = {}; // Initialize the object
angular.forEach(data, function(value, key) {
if (value.start_date > firstdayOfWeek && value.start_date < lastdayOfWeek) {
if (obj[value.athlete.firstname + ' ' + value.athlete.lastname]) { // If already exists
obj[value.athlete.firstname + ' ' + value.athlete.lastname] += value.distance; // Add value to previous value
} else {
obj[value.athlete.firstname + ' ' + value.athlete.lastname] = value.distance; // Add in object
}
} else {
//do nothing
}
});
console.log(obj); // Result
When I modify it like this it is not working anymore.
var obj = {};
angular.forEach(data, function(value, key) {
//console.log(value);
if (value.start_date > startOfLastWeek && value.start_date < endOfLastWeek) {
//console.log(value);
if (obj[value.athlete.firstname + ' ' + value.athlete.lastname]) { // If already exists
obj[value.athlete.firstname + ' ' + value.athlete.lastname] += {
"profile" : value.athlete.profile,
"distance" : value.distance,
"moving_time" : value.moving_time,
"elapsed_time" : value.elapsed_time,
"total_elevation_gain" : value.total_elevation_gain,
}; // Add value to previous value
} else {
obj[value.athlete.firstname + ' ' + value.athlete.lastname] = {
"profile" : value.athlete.profile,
"distance" : value.distance,
"moving_time" : value.moving_time,
"elapsed_time" : value.elapsed_time,
"total_elevation_gain" : value.total_elevation_gain,
}; // Add in object
}
} else {
//do nothing
}
});
console.log(obj); // Result
Thanks!

Answer 1

try to add item by item... You can't add all with += { ... }:
var obj = {};
angular.forEach(data, function(value, key) {
//console.log(value);
if (value.start_date > startOfLastWeek && value.start_date < endOfLastWeek) {
//console.log(value);
if (obj[value.athlete.firstname + ' ' + value.athlete.lastname]) { // If already exists
var aux = obj[value.athlete.firstname + ' ' + value.athlete.lastname];
aux.profile += value.athlete.profile;
aux.distance += value.distance;
...
} else {
obj[value.athlete.firstname + ' ' + value.athlete.lastname] = {
"profile" : value.athlete.profile,
"distance" : value.distance,
"moving_time" : value.moving_time,
"elapsed_time" : value.elapsed_time,
"total_elevation_gain" : value.total_elevation_gain,
}; // Add in object
}
} else {
//do nothing
}
});
console.log(obj); // Result

Answer 2

Use underscore or lodash groupBy, map and reduce
with lodash:
_.chain(myArr).map(function(o) {
return {
fullname: o.athlete.firstname + ' ' + o.athlete.lastname,
distance: o.distance,
moving_time: o.moving_time,
elapsed_time: o.elapsed_time,
total_elevation_gain: o.total_elevation_gain
}
}).groupBy(function(o) {
return o.fullaname
}).map(function(d, fullname) {
var totals = _.reduce(d, function(result, run, n) {
result.moving_time += run.moving_time | 0
result.elapsed_time += run.elapsed_time | 0
result.total_elevation_gain += run.total_elevation_gain | 0
return result
}, {
moving_time: 0,
elapsed_time: 0,
total_elevation_gain: 0
})
totals.fullname = fullname
return totals
})