Laravel load settings from database

问题:

I'm looking for an efficient way to load settings/configuration from the database with Laravel 5. Settings consist of a key and value column, the model class basically looks like this:

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Setting extends Model
{
    protected $table = 'settings';
    protected $fillable = ['key', 'value'];
    protected $primaryKey = 'key';
}

At first I made a simple helper function which does the job. The problem is, this would lead to multiple calls per page request. Which is getting slow.

/**
 * Get the value for the given setting from the database.
 *
 * @param  string  $key
 * @return string
 */
function setting($key)
{
    $setting = Setting::whereKey($key)->firstOrFail();

    return $setting->value;
}

// $foo = setting('foo'); returns 'bar'

In an attempt to improve this I creating a custom class called Setting within the App\Classes directory (and also created a Facade for it):

<?php

namespace App\Classes;

use Cache;

class Setting {

    /**
     * The array of settings
     *
     * @var array $settings
     */
    protected $settings = [];

    /**
     * Instantiate the class.
     */
    public function __construct()
    {
        $this->loadSettings();
    }

    /**
     * Pull the settings from the database and cache them.
     *
     * @return void;
     */
    protected function loadSettings()
    {
        $settings = Cache::remember('settings', 24*60, function() {
            return \App\Setting::all()->toArray();
        });

        $this->settings = array_pluck($settings, 'value', 'key');
    }

    /**
     * Get all settings.
     *
     * @return array;
     */
    public function all()
    {
        return $this->settings;
    }

    /**
     * Get a setting value by it's key.
     * An array of keys can be given to retrieve multiple key-value pair's.
     *
     * @param  string|array  $key;
     * @return string|array;
     */
    public function get($key)
    {
        if( is_array($key) ) {
            $keys = [];

            foreach($key as $k) {
                $keys[$k] = $this->settings[$k];
            }

            return $keys;
        }

        return $this->settings[$key];
    }

}

// $foo = Setting::get('foo');

And now for my question: is this the best way to tackle this problem? I'm now caching all the settings when the class gets constructed. And then retrieve setting values from the cache after that.

I'm beginning to understand the Repository pattern in L5, but I'm not there yet. I thought that would be overkill in this case. I would love to hear if my approach makes any sence.

回答1:

IMHO it's a bit over engineered. You can do the same with the helper approach:

function settings($key)
{
    static $settings;

    if(is_null($settings))
    {
        $settings = Cache::remember('settings', 24*60, function() {
            return array_pluck(App\Setting::all()->toArray(), 'value', 'key');
        });
    }

    return (is_array($key)) ? array_only($settings, $key) : $settings[$key];
}

Less cumbersome. No loops. Max 1 DB hit per request. Max 1 Cache hit per request.

回答2:

Here is an updated answer as of Laravel 5.5.

First, create a migration for your settings table:

Schema::create('settings', function (Blueprint $table) {
    $table->increments('id');
    $table->string('key');
    $table->text('value')->nullable();
    $table->timestamps();
});

Then create a Setting model:

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Setting extends Model
{
    protected $fillable = ['key', 'value'];
}

Now, in AppServiceProvider, add the following to your boot() method:

if (Schema::hasTable('settings')) {
    foreach (Setting::all() as $setting) {
        Config::set('settings.'.$setting->key, $setting->value);
    }
}

This will create config('settings.*') for each setting in your database, where * is the key.

For example, insert/create the following setting:

Setting::create([
    'key' => 'example',
    'value' => 'Hello World',
]);

Now you can access config('settings.example'), which will give you Hello World.

Updating settings is as simple as doing:

Setting::where('key', 'example')->update([
    'value' => 'My New Value',
]);

回答3:

The OP led me down the path to develop this package, which saves key-pair values to a settings table and uses cache to reduce DB queries. If you're looking for your own solution, feel free to take a look at my code.

回答4:

Here is how I solved it in Laravel 5.4. I have a database table called configurations and created a model for it called Configuration. The configurations have a key and value like you mentioned. Of course you can change this to Settings if you want.

In AppServiceProvider boot() add:

// cache configuration
Cache::forever('configuration', Configuration::all());

Create a helper function (I put this in App\Http\helpers.php which is in my composer autoload):

function configuration($key)
{
    return Cache::get('configuration')->where('key', $key)->first()->value;
}

Then you can access the value anywhere using configuration('key_name') etc.