I have an array of timeseries objects that I need to filter in React.
Specifically, I need to return an array containing a filtered subset of the array of objects, based on the value of device_id being equal to e.g. 7F34B296.
The raw array looks as below:
[
{
"label": "time_stamp",
"data": [
"2019-04-17 21:01:25.673949957+02:00",
"2019-04-17 21:01:30.673949957+02:00",
"2019-04-17 21:01:35.673949957+02:00",
"2019-04-17 21:01:40.673949957+02:00",
"2019-04-17 21:01:45.673949957+02:00"
]
},
{
"label": "device_id",
"data": [
"7F34B296",
"7F34B296",
"7F34B296",
"AB22438D",
"AB22438D"
]
},
{
"label": "parameter_x",
"data": [
"929.1965116",
"927.5152582",
"928.7476077",
"1919.2691327",
"1918.7047619"
]
}
]
The intended output array (after filtering) looks as below:
[
{
"label": "time_stamp",
"data": [
"2019-04-17 21:01:25.673949957+02:00",
"2019-04-17 21:01:30.673949957+02:00",
"2019-04-17 21:01:35.673949957+02:00"
]
},
{
"label": "device_id",
"data": [
"7F34B296",
"7F34B296",
"7F34B296"
]
},
{
"label": "parameter_x",
"data": [
"929.1965116",
"927.5152582",
"928.7476077"
]
}
]
I tried using various methods, including below - but I seem unable to get the desired result. I think I'm missing the part on how to handle that the filtering of the entire array of objects should depend on the value of a subset of one of the objects.
const filters = [
{
predicateFn: data => data.data == "7F34B296"
}
];
function getFilteredPersons(filters) {
return datasets.filter(p => filters.every(filter => filter.predicateFn(p)));
}
console.log(getFilteredPersons(filters));
I have an array of timeseries objects that I need to filter in React.
Specifically, I need to return an array containing a filtered subset of the array of objects, based on the value of device_id being equal to e.g. 7F34B296.
The raw array looks as below:
[
{
"label": "time_stamp",
"data": [
"2019-04-17 21:01:25.673949957+02:00",
"2019-04-17 21:01:30.673949957+02:00",
"2019-04-17 21:01:35.673949957+02:00",
"2019-04-17 21:01:40.673949957+02:00",
"2019-04-17 21:01:45.673949957+02:00"
]
},
{
"label": "device_id",
"data": [
"7F34B296",
"7F34B296",
"7F34B296",
"AB22438D",
"AB22438D"
]
},
{
"label": "parameter_x",
"data": [
"929.1965116",
"927.5152582",
"928.7476077",
"1919.2691327",
"1918.7047619"
]
}
]
The intended output array (after filtering) looks as below:
[
{
"label": "time_stamp",
"data": [
"2019-04-17 21:01:25.673949957+02:00",
"2019-04-17 21:01:30.673949957+02:00",
"2019-04-17 21:01:35.673949957+02:00"
]
},
{
"label": "device_id",
"data": [
"7F34B296",
"7F34B296",
"7F34B296"
]
},
{
"label": "parameter_x",
"data": [
"929.1965116",
"927.5152582",
"928.7476077"
]
}
]
I tried using various methods, including below - but I seem unable to get the desired result. I think I'm missing the part on how to handle that the filtering of the entire array of objects should depend on the value of a subset of one of the objects.
const filters = [
{
predicateFn: data => data.data == "7F34B296"
}
];
function getFilteredPersons(filters) {
return datasets.filter(p => filters.every(filter => filter.predicateFn(p)));
}
console.log(getFilteredPersons(filters));
- so each array in the object are in the same sorted order? – arizafar Commented Sep 16, 2019 at 9:31
-
Yes, that is correct. The raw data es from an SQL query based on a simple CSV database. To avoid having to call the SQL query for each
device_id, I instead include the device_id as a column in the query output and aim to filter the data once fetched to split it bydevice_id. I've not found other posts where the filtering of the entire array has to be done based on the object data of one of the arrays. – mfcss Commented Sep 16, 2019 at 9:35 -
It won't work with
filterby itself, you need tomapthe object - adding anidto each entry, thenfilterby it, eventuallymapping and removing theidadded – Dennis Vash Commented Sep 16, 2019 at 9:39 - Or doing it in a nested loop which will be unreadable. – Dennis Vash Commented Sep 16, 2019 at 9:40
- Is device_id always at index 1 of array? – zhuber Commented Sep 16, 2019 at 9:42
3 Answers
Reset to default 2Maybe try to map your data to some kind of the structure f.e.:
const joinedData = []
data.map((element) =>
element.data.map((e, i) => joinedData[i] = { [element.label]: e, ...joinedData[i]}))
Then you will have transformed data in shape:
[
{
parameter_x: '929.1965116',
device_id: '7F34B296',
time_stamp: '2019-04-17 21:01:25.673949957+02:00'
},
{
parameter_x: '927.5152582',
device_id: '7F34B296',
time_stamp: '2019-04-17 21:01:30.673949957+02:00'
},
{
parameter_x: '928.7476077',
device_id: '7F34B296',
time_stamp: '2019-04-17 21:01:35.673949957+02:00'
},
{
parameter_x: '1919.2691327',
device_id: 'AB22438D',
time_stamp: '2019-04-17 21:01:40.673949957+02:00'
},
{
parameter_x: '1918.7047619',
device_id: 'AB22438D',
time_stamp: '2019-04-17 21:01:45.673949957+02:00'
}
]
which will be easier to filter
If your data object is always structured same way (3 elements each on same place), then you can do something like this:
const data = [
{
"label": "time_stamp",
"data": [
"2019-04-17 21:01:25.673949957+02:00",
"2019-04-17 21:01:30.673949957+02:00",
"2019-04-17 21:01:35.673949957+02:00",
"2019-04-17 21:01:40.673949957+02:00",
"2019-04-17 21:01:45.673949957+02:00"
]
},
{
"label": "7F34B296",
"data": [
"7F34B296",
"7F34B296",
"7F34B296",
"AB22438D",
"AB22438D"
]
},
{
"label": "parameter_x",
"data": [
"929.1965116",
"927.5152582",
"928.7476077",
"1919.2691327",
"1918.7047619"
]
}
]
const mainData = data[1];
const deviceId = mainData.label;
const indexes = mainData.data.filter((item) => item === deviceId).map((e, idx, array) => idx);
const result = data.map((value) => {
const filteredData = value.data.filter((item, idx) => {
return indexes.some((e => idx === e));
})
return {
...value,
data: filteredData
}
});
console.log(result)Basically just find indexes of device_id in second element of array, and then extract values on those indexes of device_id, time_stamp and parameter_x data properties.
Although this might work, I'd suggest restructuring your data because this is quite plicated structure.
We can use forEach method with splice to get desired output.
let arr = [
{
"label": "time_stamp",
"data": [
"2019-04-17 21:01:25.673949957+02:00",
"2019-04-17 21:01:30.673949957+02:00",
"2019-04-17 21:01:35.673949957+02:00",
"2019-04-17 21:01:40.673949957+02:00",
"2019-04-17 21:01:45.673949957+02:00"
]
},
{
"label": "device_id",
"data": [
"7F34B296",
"7F34B296",
"7F34B296",
"AB22438D",
"AB22438D"
]
},
{
"label": "parameter_x",
"data": [
"929.1965116",
"927.5152582",
"928.7476077",
"1919.2691327",
"1918.7047619"
]
}
]
arr.forEach( (val, index) => val.data.splice(3) )
console.log(arr)