How can I paginate an array of objects in Laravel?

问题

I'm building an application using Laravel 4.2. I have a model for units and another for users and pivot table user_units. Every user in this application can select a unit and add it to his favorite list then he can publish this unit with his information as an ad.

I want to select all units published by all users

The user_units (pivot) table has the following columns:

id   
user_id 
unit_id 
publish      
adtype       
addinfo          
created_at  
updated_at

With relations methods on models

public function users() {
    return $this->belongsToMany('User', 'user_units')
                ->withPivot('id','publish', 'adtype', 'addinfo');
}

public function units() {
    return $this->belongsToMany('Unit', 'user_units')
                ->withPivot('id','publish', 'adtype', 'addinfo');
}

My query to select all published units by all users

// Get all published units by users for sale. 
    $users = User::all();
    $publishedSaleUnits = [];
    foreach($users as $user){
        $userUnits = $user->units()->orderBy('adtype', 'desc')->get();
        if(count($userUnits)){
            foreach($userUnits as $unit){
                if($unit->pivot->publish == 1 && $unit->unit_purpose_id == 1){
                    if( $unit->pivot->adtype ){
                        //push all featured ads onto the beginning of array
                        array_unshift($publishedSaleUnits, $unit);
                    }else{
                        //push all normal ads onto the end of array
                        array_push($publishedSaleUnits, $unit);
                    }
                }
            }
        }
    }

Now I got the result but I can't use pagination with results because it's an array of objects.

So is there any better solution to get all published units by user with pagination?

回答1:

Your approach to query the data is extremely inefficient. Fetch your data in one query. Nested traversing is not only hard to read but also a performance killer.

To the pagination problem:

Laravel provides a Pagignator Factory. With it you will be able to build your own Paginator with your own data.

It's as easy as

$units = Paginator::make($unit, count($unit), 10);

if you're using the Facade. Otherwise Illuminate\Pagination\Factory is the class you are looking for.

回答2:

I got a better solution to paginate array result and I found the answer here

Paginator::make function we need to pass only the required values instead of all values. Because paginator::make function simply displays the data send to it. To send the correct offset paginated data to the paginator::make, the following method should be followed

    $perPage = 5;   
    $page = Input::get('page', 1);
    if ($page > count($publishedSaleUnits) or $page < 1) { $page = 1; }
    $offset = ($page * $perPage) - $perPage;
    $perPageUnits = array_slice($publishedSaleUnits,$offset,$perPage);
    $pagination = Paginator::make($perPageUnits, count($publishedSaleUnits), $perPage);

回答3:

You can try my code with your own array,

$page = isset($request->page) ? $request->page : 1; // Get the page=1 from the url
$perPage = $pagination_num; // Number of items per page
$offset = ($page * $perPage) - $perPage;

$entries =  new LengthAwarePaginator(
    array_slice($contact_list, $offset, $perPage, true),
    count($contact_list), // Total items
    $perPage, // Items per page
    $page, // Current page
    ['path' => $request->url(), 'query' => $request->query()] // We 
       need this so we can keep all old query parameters from the url
);

来源：https://stackoverflow.com/questions/27064953/how-can-i-paginate-an-array-of-objects-in-laravel

标签

laravel-4

pagination

pivot-table