Laravel flatten won't flatten array error - php

Question

In my Laravel project I'm trying to flatten an array to ensure consistency, for some reason, the attached screenshot showing my data format returned from my project won't flatten with the flatten() method.
I get an error:
Error: Call to a member function flatten() on array
Which is quite generic, I've tried using ->toArray() before flattening but this doesn't give me any data, what am I doing wrong here?
The logic exists within a Laravel job, thus the console log
/**
* Group data
*
* #return void
*/
public function groupData(
$data,
$groupBy,
$groupByFormat,
$additionFromField = ''
) {
$results = $data->groupBy(function ($item, $key) use ($groupBy, $groupByFormat) {
$date = Carbon::parse($item->{$groupBy});
return $date->format($groupByFormat);
});
// grouping by some kind of total
if (!empty($additionFromField)) {
$results = $results->map(function ($item, $key) use ($additionFromField) {
$totals = 0;
foreach ($item as $key => $value) {
$totals += $value->{$additionFromField};
}
return [
'items' => count($item),
'total' => $totals ?? 0
];
});
$calcedData = [];
foreach ($results as $key => $result) {
array_push($calcedData, [
'period_to' => $key,
'items' => $result['items'],
'total' => $result['total']
]);
}
return $calcedData;
}
// standard grouping of data
$results = $results->map(function ($item, $key) {
return $item[0];
});
return $results;
}
/**
* Execute the job.
*
* #return void
*/
public function handle()
{
$filters = json_decode($this->report->discovery_filters, true);
$data = [];
foreach ($filters as $findableKey => $findable) {
/*
** If there are datasets on the findable objec, then we assume
** that we can build up a chart or some data structure.
*/
if (isset($findable['datasets'])) {
$pushableDatasets = [];
foreach ($findable['datasets'] as $datasetKey => $dataset) {
// query data
if (isset($dataset['query'])) {
$additionFromField = $dataset['query']['additionFromField'] ?? '';
$res = DB::table($dataset['query']['table'])
->select($dataset['query']['columns'])
->where($dataset['query']['filterBy'])
->orderBy($dataset['query']['orderBy']['field'], $dataset['query']['orderBy']['direction'])
->get()
->chunk(100);
$res = $res->flatten();
if (isset($dataset['query']['useGrouping']) && $dataset['query']['useGrouping'] == 'yes') {
$results = $this->groupData(
$res,
$dataset['query']['groupBy'],
$dataset['query']['groupByFormat'],
$additionFromField
);
var_dump($results); // shown in the screenshot
$resultData = $results->flatten();
array_push($pushableDatasets, $this->getStructure($findable, $datasetKey, $resultData));
}
}
}
$findable['datasets'] = $pushableDatasets;
}
array_push($data, $findable);
}
}

Answer 1

Error: Call to a member function flatten() on array
The error message is quite accurate and descriptive. flatten is a member function of an object (in this case, the Laravel Collection object) and an array is not an object.
You need to convert the array to a collection first, then you can flatten it:
$flattened = collect($results)->flatten();

Answer 2

$new = collect($results)->flatten();
In your case you can also use array_flatten() I guess. Here is the documentation https://laravel.com/docs/5.1/helpers#method-array-flatten