Create and call member functions similar to laravel - php

Question

How can we create member functions in php that can be called similarly to the way laravel does?
ex:
User::with('package')->where('id', $user_id)->get();
i tried creating a static function with a member function inside:
public static function getAll() {
public function withJoin($join_table, $local_key, $foreign_key) {
global $wpdb;
$table_name = $wpdb->prefix.'qre_events';
$query = "SELECT * from $table_name INNER JOIN $join_table ON $local_key = $foreign_key";
try {
$results = $wpdb->get_results($query);
} catch(Throwable $e) {
$results = null;
echo($e);
echo "Error retrieving data.";
}
var_dump($results);
}
global $wpdb;
$table_name = $wpdb->prefix. static::$table_name;
$query = "SELECT * from $table_name";
try {
$results = static::convertArrayToModelArray($wpdb->get_results($query),
static::$attributes);
} catch(Throwable $e) {
$results = null;
echo($e);
echo "Error retrieving data.";
}
return $results;
}
and tried calling it like so:
$results = Event::getAll()->withJoin($user_table, 'user_id', 'ID');
but it returned this error:
Fatal error: Uncaught Error: Call to a member function withJoin() on array

Answer 1

The method chaining is archived by returning $this for each method.
Like this:
class Event
{
public function getAll()
{
// Do stuff
return $this;
}
public function withJoin()
{
// Do stuff
return $this;
}
}
Now they can be called like this:
(new Event)->getAll()->withJoin();
So you have to save you parameters to properties on the class.
You can take a look inside Laravel builder to see exactly how it was archived there: https://github.com/laravel/framework/blob/6.x/src/Illuminate/Database/Eloquent/Builder.php

Answer 2

Try .
$results = Event::withJoin($user_table, 'user_id', 'ID')->get();

Answer 3

The chaining of methods works because each function returns an instance of an object that has functions on it.
// This
User::with('package')->where('id', $user_id)->get();
// Is basicly the same as
$user_query = User::with('package');
$user = $user_query->where('id', $user_id)->get();
You need to create two objects and the static function will return an instance of the other object. If you want method chaining as well, you just need to make sure that chainable functions return their own instance.
For example
class Event
{
public static function getAll()
{
return new EventObject();
}
}
class EventObject
{
public function withJoin()
{
// Do stuff here.
// return `$this` if you want to chain functions.
}
}
In this example, using Event::getAll() will give you an EventObject instance on which you can call the withJoin function. So you can now do the following:
Event::getAll()->withJoin();