How to group models array in yii2 - php

Question

Hi everyone i have a page on which i am displaying data using foreach loop from models. I wants to know that how can i group those classes and display accordingly.
For example I have registration forms on the page which has dates and classes.
So i want to group them by dates first and than classes.My registration models has fields like below.
Registration
id
event_id
dates
class_id
user_id
title
description
Now on this view file i am passing array of $modelRegistration so i dont actually have simple multi dimensional array so i cant use that logic to group that and display.Here is my view code to display the forms
<table class="table table-bordered table-striped">
<thead>
<tr>
<th>Date</th>
<th>Class</th>
<th>User Name</th>
<th>Title</th>
<th>Description</th>
</tr>
</thead>
<tbody class="container-items">
<?php foreach ($modelsRegistration as $indexRegistration => $modelRegistration): ?>
<tr value="<?= $modelRegistration->date ?>" class="house-item">
<td class="col-lg-1 col-md-1 col-sm-1 col-xs-1"><?= $modelRegistration->class->name ?></td>
<td class="col-lg-2 col-md-2 col-sm-2 col-xs-2">
<label><?= $modelRegistration->user->name ?></label>
<td class="col-lg-2 col-md-2 col-sm-2 col-xs-2"><?= $modelRegistration->title ?> </td>
<td class="col-lg-1 col-md-1 col-sm-1 col-xs-1"><?= $modelClass->description ?> </td>
</tr>
<?php endforeach; ?>
</tbody>
I want to get array like below
Registration
(
[0] => 10/12/2015
(
[0] => class-1(
[0] => array(
[title] => "Title 1"
[id] => 5
[username] => John
[Description] => Team Leader
)
[1] => array(
[title] => "Title 2"
[id] => 6
[username] => John 1
[Description] => Team 2
)
)
[1] => class-2(
[0] => array(
[title] => "Title 4"
[id] => 7
[username] => John 4
[Description] => Team 4
)
[1] => array(
[title] => "Title 5"
[id] => 9
[username] => John 5
[Description] => Team 6
)
)
[2] => class-3(
[0] => array(
[title] => "Title 1"
[id] => 5
[username] => John
[Description] => Team Leader
)
[1] => array(
[title] => "Title 2"
[id] => 6
[username] => John 1
[Description] => Team 2
)
)
)
[0] => 12/12/2015
(
[0] => class-1(
[0] => array(
[title] => "Title 8"
[id] => 12
[username] => John 10
[Description] => Team 77
)
[1] => array(
[title] => "Title 27"
[id] => 67
[username] => John 17
[Description] => Team 27
)
)
[1] => class-3(
[0] => array(
[title] => "Title 41"
[id] => 71
[username] => John 41
[Description] => Team 41
)
[1] => array(
[title] => "Title 51"
[id] => 59
[username] => John 54
[Description] => Team 64
)
)
)
If i can group it by dates first and than classes than i want to display the date only once and than under that date all the grouped classes and under classes i can display other information.Thank you

Answer 1

Map Your Model Data using date group Array helper Map Group in yii2
$model = Registration::findAll();
$registrationModels = ArrayHelper::map($model , 'event_id' ,'class_id' ,'dates');

Answer 2

Suppose that your model name is Registration and view name is vrego.
In your controller
// select all and order by date and class_name
$registrations= Registration::find()
->orderBy('date, class_name')
->all();
return $this->render('vrego', [
'registrations' => $registrations,
]);
Then in your view loop through $registrations and display each record.

Answer 3

i am geting the result i tried my self :
you need to create a class of Registration and i think you created that one then use this below query you will get that info .
$events = Registration::find()->all();
foreach($events as $event){
$new_array[$event->dates_date][][$event->class_id][]=$event;
}
<pre>
after print_r($new_array);
<pre>