Adding values to array in a loop - php

Question

Iam working on a laravel project which stores values to a DB entry in loop on meeting certain conditions.
This first creates an array if the entry is for the first time and adds a value to it. Henceforth, it recalls the array and keeps adding values to it.
if(is_null($lead->shown_to)) {
$a = array();
array_push($a, "lead 1");
$lead->shown_to = serialize($cart);
$lead->save();
} else {
$a=unserialize($lead->shown_to);
array_push($a, "lead 2");
$lead->shown_to = serialize($a);
$lead->save();
}
To be able to create an array and add distinct elements to it repeatedly.
Is there a way to first check if the element exists in it or not. If it does, just move ahead, else add it?
Thanks in advance.

Answer 1

There're a couple of methods you can use.
You can first look for the value on the DB if exists using a column from the database like:
$result = Model::where( 'column', 'value' );
if ( $result ) {
// update already exists
} else {
// create one
}
// Retrieve flight by name, or create it if it doesn't exist...
$flight = App\Flight::firstOrCreate(['name' => 'Flight 10']);
// Retrieve by name, or instantiate...
$flight = App\Flight::firstOrNew(['name' => 'Flight 10']);
Also it depends what you are looking for as firstOrCreate persists the value into the DB where firstOrNew just creates a new instance where you need to call save()

Answer 2

to check a value exists in an array you can use array_search(). this will return the value if exists. if not it returns false.
if(!array_search('lead 2', $a)) {
// array does't has 'lead 2' so,
array_push('lead 2', $a);
}

Answer 3

In Laravel I would take advantage of the Collections because they have a lot of helpful methods to work with.
I would do something like this:
OPTION 1
//Depending on the value of $lead->show, initialize the cart variable with the serialization of the attribute or and empty array and transform it to a collection.
$cart = collect($lead->shown_to ? unserialize($lead->shown_to) : []);
//Ask if the collection doesn't have the given value. If so, added it.
if (!$cart->contains($your_value)) {
$cart->push($your_value);
}
//Convert to array, serialize and store
$lead->shown_to = serialize($cart->toArray());
$lead->save();
OPTION 2
//Depending on the value of $lead->show, initialize the cart variable with the serialization of the attribute or and empty array and transform it to a collection.
$cart = collect($lead->shown_to ? unserialize($lead->shown_to) : []);
//Always push the value
$cart->push($your_value);
//Get the unique values, convert to an array, serialize and store
$lead->shown_to = serialize($cart->unique()->toArray());
$lead->save();
You can get more creative using the collections and they read better on Laravel

Answer 4

I think you can use updateOrCreate, if not exists it will create now, if exists, it will update it, so you can keep assigning value to shown_to property
$lead= App\Lead::updateOrCreate(
['name' => 'Lead 1'],
['shown_to' => serialize($a)]
);
if you wan to keep the existing shown_to better to use json data, so that you can do like
$lead= App\Lead::updateOrCreate(
['name' => 'Lead 1'],
['shown_to' => json_encode(array_push(json_decode($a), $newData))]
);