How to make a Ajax Request on Laravel when dropdown menu is clicked

Question

I have a instance and category table. There is a many to many relationship between them. I need to fetch all the categories belonging to instance via a ajax request when the instance is selected from the dropdown menu. How do I achieve this?

Method 1:

View

$('#instance_id').change(function(){

    var url = $('Form#CreateArticleForm').prop('action');//get the base url specified on the form
    var method = $('Form#CreateArticleForm').prop('method');//get method action
    var data = $('Form#CreateArticleForm').serialize();//get all the data submitted via form

    url = url + "/instanceCategoryDomain"; //say we wan to call instanceCategoryDomain() on controller 

    $.ajax({
        url: url,
        type: get_method,
        data: data,

        success: function(result) {
            var jsonResult = $.parseJSON(result);
            console.log(jsonResult);
        }
    });
});

Route:

Route::get('articles/instanceCategoryDomain', 'ArticlesController@instanceCategoryDomain');

Controller

class ArticlesController {
    public function instanceCategoryDomain()
    {
        $instance_id = Request::input('instance_id');

        $output['instance'] = [$instance_id];
        return json_encode($output);
    }
}

Method 2:

View

$('#instance_id').change(function(){

    var url = $('Form#CreateArticleForm').prop('action');
    var method = 'get';
    var instance_id = $(this).val();

    url = url + "/instanceCategoryDomain/"+instance_id;

    $.ajax({
        url: url,
        type: get_method,

        success: function(result) {
            var jsonResult = $.parseJSON(result);
            console.log(jsonResult);
        }
    });
});

Route:

    Route::resource('articles/instanceCategoryDomain/{instance_id}', 'ArticlesController@instanceCategoryDomain');

Controller

class ArticlesController {
    public function instanceCategoryDomain($instance_id)
    {
        $output['instance'] = [$instance_id];//suppose
        return json_encode($output);
    }
}

Hope this helps!