How to add a new field to a Model and use it in Eloquent

Question

I'm trying the following: I have a model, called Pub, that has the following fields: "id","name","address","longitude","latitude","schedule","photo", etc.

As I need to know the distance between Pub and User, so I've created a function that calculates the distance in Pub Model using longitude and latitude:

public function pubDistance()
{
    $userLat = '';
    $userLong = '';

    $pubLat = $this->latitude;
    $pubLong = $this->longitude;

    if(!($userLat && $userLong))
    {
        $userLat = 40.4169473;
        $userLong = -3.7035285;
    }

    $earthRadius = 6371;

    $latFrom = deg2rad($userLat);
    $lonFrom = deg2rad($userLong);
    $latTo = deg2rad($pubLat);
    $lonTo = deg2rad($pubLong);

    $latDelta = $latTo - $latFrom;
    $lonDelta = $lonTo - $lonFrom;

    $a = pow(cos($latTo) * sin($lonDelta), 2) +
        pow(cos($latFrom) * sin($latTo) - sin($latFrom) * cos($latTo) * cos($lonDelta), 2);

    $b = sin($latFrom) * sin($latTo) + cos($latFrom) * cos($latTo) * cos($lonDelta);

    $angle = atan2(sqrt($a), $b);

    $distance = round($angle * $earthRadius, 2);

    return $distance;

}

And I use this function here (inside Pub model too):

public function getPubDistanceToUserAttribute()
{
    return $this->pubDistance();
}

Then the problem I have is how to add the field to Pub model and use to order my pubs by distance.

The first thing I could do it appending:

protected $appends = ['pub_distance_to_user'];

But I'm having problems in my controller to order by that new field:

public function getPubs()
{
    $pubs = Pub::all();

    return $pubs;
}

This is what I have:

{
"id": 1,
"name": "Dr. Nikko Braun",
"address": "453 Wyman Crossroad\nSouth Eliashaven, NY 75636",
"longitude": "118.9395890",
"latitude": "-62.3235600",
"schedule": "1986-11-13 10:15:48",
"photo": 
"email": "sylvester.rutherford@example.net",
"phone": "1-841-349-8925 x684",
"pub_distance_to_user": 15556.09

}

How I could use accesors and mutators here, or something like this in this case?...

Thanks a lot!!

Answer 1

Define this in your getPubs function, since $pubs is a collection we can use the sortBy/sortByDesc method to sort the collection by ascending or descending. In this case we want ascending to have the lowest digit first.

Source: Laravel Documentation / sortBy

Second Source: Similar to this SO answer

public function getPubs()
{
    $pubs = Pub::all();
    $sorted = $pubs->sortBy('pub_distance_to_user');
    return $sorted;
}

Answer 2

I don't think you can do this on the query, but it should be easy to do it on the collection:

$pubs = Pub::all()->sortBy(function ($pub) {
     return $pub->pubDistance();
});

Answer 3

Ok so you can add a field in the function getPubs() by using the foreach loop,

Try this,

public function getPubs()
{
    $pubs = Pub::all();

    foreach($pubs as $pub){
    $pub->pub_distance_to_user = Pub::pubDistance();
    }

    return $pubs->sortBy('pub_distance_to_user');
}

EDIT:

I think you can define your function to calcluate distance with arguments, like this way

public function pubDistance($pubLat,$pubLong)
{

$userLat = '';
$userLong = '';

if(!($userLat && $userLong))
{
    $userLat = 40.4169473;
    $userLong = -3.7035285;
}

$earthRadius = 6371;

$latFrom = deg2rad($userLat);
$lonFrom = deg2rad($userLong);
$latTo = deg2rad($pubLat);
$lonTo = deg2rad($pubLong);

$latDelta = $latTo - $latFrom;
$lonDelta = $lonTo - $lonFrom;

$a = pow(cos($latTo) * sin($lonDelta), 2) +
    pow(cos($latFrom) * sin($latTo) - sin($latFrom) * cos($latTo) * cos($lonDelta), 2);

$b = sin($latFrom) * sin($latTo) + cos($latFrom) * cos($latTo) * cos($lonDelta);

$angle = atan2(sqrt($a), $b);

$distance = round($angle * $earthRadius, 2);

return $distance;

}

And then you have to call function by Pub::pubDistance($pub->latitude,$pub->longitude);

public function getPubs()
{
    $pubs = Pub::all();

    foreach($pubs as $pub){
    $pub->pub_distance_to_user = Pub::pubDistance($pub->latitude,$pub->longitude);
    }

    return $pubs->sortBy('pub_distance_to_user');
}

Answer 4

You should try this:

Please add below code with your table field in your model:

/**
     * Attributes that should be mass-assignable.
     *
     * @var array
     */
    protected $fillable = ['yorr_field1','yorr_field1','yorr_field3'];