Laravel collection turns empty inside foreach loops - php

Question

I have 3 collections on different items that I need to show and group by date, in the blade file I loop over the dates to show these collections, but for some reason whatever the first collection is, something wrong happens with it, it shouldn't change based on the date, let's say I have two dates (2019-03, 2019-01), I end up with two different instances of the same collection, one with the data, and one without(an empty collection), even though I am calling the same variable.
The controller method:
public function index()
{
//Retrieving the Models.
$invoices_egp = auth()->user()->invoices()->where('paid', 1)->where('currency', 'EGP');
$invoices_usd = auth()->user()->invoices()->where('paid', 1)->where('currency', 'USD');
$orders = \App\Order::where('vendor_id', auth()->user()->id)->where('paid', 1);
//Getting the different dates of these Models.
$egp_invoices_dates = $invoices_egp->get()->map(function ($invoice) {
return Carbon::parse($invoice->created_at)->format('Y-m');
});
$usd_invoices_dates = $invoices_usd->get()->map(function ($invoice) {
return Carbon::parse($invoice->created_at)->format('Y-m');
});
$orders_dates = $orders->get()->map(function ($order) {
return Carbon::parse($order->created_at)->format('Y-m');
});
//Getting the unique dates.
$dates = $orders_dates->merge($usd_invoices_dates)->merge($egp_invoices_dates)->unique();
return view('dashboard.vendor.reports.index', compact('invoices_egp', 'invoices_usd', 'orders', 'dates'));
}
The relevant part of the blade file:
<div class="col-lg-12">
#if ( count( $dates ) )
#foreach($dates as $date)
<div class="card-box">
<div class="table-responsive">
<table class="table table-actions-bar m-b-0">
<thead>
<tr>
<th>
Month
</th>
</tr>
<tr>
<td>
{{ $date }}
</td>
</tr>
</thead>
<tbody>
<tr>
<th colspan="100%">Type</th>
<th>Total</th>
</tr>
<tr>
#if(count($invoices_egp->get()))
<td colspan="100%">Invoice in EGP</td>
<td>{{ $invoices_egp->whereYear('paid_at', \Carbon\Carbon::parse($date)->year)->whereMonth('paid_at', \Carbon\Carbon::parse($date)->month)->sum('total') }}</td>
#endif
</tr>
<tr>
#if(count($invoices_usd->get()))
<td colspan="100%">Invoice in USD</td>
<td>{{ $invoices_usd->whereYear('paid_at', \Carbon\Carbon::parse($date)->year)->whereMonth('paid_at', \Carbon\Carbon::parse($date)->month)->sum('total') * \App\ConversionRate::dollarToEGP() }}</td>
#endif
</tr>
<tr>
#if(count($orders->get()))
<td colspan="100%">Orders</td>
<td>{{ $orders->whereYear('paid_at', \Carbon\Carbon::parse($date)->year)->whereMonth('paid_at', \Carbon\Carbon::parse($date)->month)->sum('total') }}</td>
#endif
</tr>
</tbody>
</table>
</div>
</div>
#endforeach
#else
<div class="card-box">
<h3>No Data</h3>
</div>
#endif
</div>
Here when I loop over the $dates variable, for some reason, the $invoices_egp variable changes based on the date, even though it has got nothing to do with it, if I tried to dump $invoices_egp (which has two records with the same date 2019-01) on each loop, I am expecting to get the two records twice regardless of the date, instead I get the two records on the first loop ($date = 2019-03), and on the second loop ($date = 2019-01) I get an empty collection.
I have tried different stuff, I replaced the dates variable with a hard coded array and removed the other dates queries, nothing changes in the blade file.
What's even weirder is that if I changed the place of $invoices_egp with $invoices_usd, I get $invoices_egp rendered correctly, and the bug instead happens to the $invoices_usd variable, so whatever the first variable is, it gets messed up.
Small Update
I don;t know what's wrong yet, but as soon as I comment out this line
<td>{{ $invoices_egp->whereYear('paid_at', \Carbon\Carbon::parse($date)->year)->whereMonth('paid_at', \Carbon\Carbon::parse($date)->month)->sum('total') }} EGP</td>
I get the variable rendering twice correctly per each instance of the loop, which is what should happen, and this line I am commenting should not have any impact over whether the collection should be retrieved successfully or not, I hope I am making sense.
If I dump the variable over each loop, this is what I get in the first loop
Collection {#522 ▼
#items: array:2 [▼
0 => Invoice {#526 ▶}
1 => Invoice {#519 ▶}
]
}
And this is what I get in the second loop (with the aforementioned line uncommented)
Collection {#516 ▼
#items: []
}
Same variable, different results over a loop.

Answer 1

So apparently since I was passing a query builder instance to the view, it was actually getting changed by the foreach loop, which is something I'd never thought would happen, anyway the fix was easy at that point, just had to change the code a little, starting from here:
public function index()
{
$invoices_egp = auth()->user()->invoices()->where(['paid' => 1, 'currency' => 'EGP'])->latest()->get();
$invoices_usd = auth()->user()->invoices()->where(['paid' => 1, 'currency' => 'USD'])->latest()->get();
$orders = \App\Order::where('vendor_id', auth()->user()->id)->where('paid', 1)->latest()->get();
$egp_invoices_dates = $invoices_egp->map(function($invoice) { return Carbon::parse($invoice->paid_at)->format('Y-m'); })->unique();
$usd_invoices_dates = $invoices_usd->map(function($invoice) { return Carbon::parse($invoice->paid_at)->format('Y-m'); })->unique();
$orders_dates = $orders->map(function($order) { return Carbon::parse($order->paid_at)->format('Y-m'); })->unique();
$dates = $orders_dates->merge($usd_invoices_dates)->merge($egp_invoices_dates)->unique();
return view('dashboard.vendor.reports.index', compact('invoices_egp', 'invoices_usd', 'orders', 'dates'));
}
And in the view I just had to change the filtering queries to be like this for all 3 queries:
<td>{{ $invoices_egp->filter(function($invoice) use ($date) { return $invoice->created_at->year == \Carbon\Carbon::parse($date)->year; })->filter(function($invoice) use ($date) { return $invoice->created_at->month == \Carbon\Carbon::parse($date)->month; })->sum('total') }} EGP</td>