php Laravel的Flash消息最小服务（仅后端）

Posted 2021-05-05

## Simple use

In Controllers:

```php
  flash('Some info message');
  flash()->error('This is some error!')
  //flash()->warning
  //flash()->success
  //flash()->info
```

In Template:

```
  @foreach(flash()->messages() as $message)
    <div>{{ $message->level }}: {{ $message->text }}</div>
  @endforeach
```

Or only one message level:

```
  @foreach(flash()->messages('danger') as $message)
    <div class="alert-danger">{{ $message->text }}</div>
  @endforeach
  @foreach($errors->all() as $message)
    <div class="alert-danger">{{ $message }}</div>
  @endforeach
```

## Multiple messages

```php
  flash()->warning('Warning One');
  flash()->warning('Warning Two');
  flash()->success('But we did it')
```

## Extra data for messages    

And possible add some extra data with message:

```php
  flash()->error('This error show in modal', ['important' => true])
```

and read it in view

```
  @foreach(flash()->messages() as $message)
    <div class="message" @if(!empty($message->important)) data-modal="" @endif>
      {{ $message->text }}
    </div>
  @endforeach
```

<?php

//app/Servides/Foundation/helpers.php

if (! function_exists('flash')) {
    /**
     * Make a flash message or retrieve a FlashMessageSender instance.
     *
     * @param string $message
     * @param array $data
     * @return \Adteam\Services\Foundation\FlashMessageSender
     */
    function flash(string $message = null, array $data = [])
    {
        if (is_null($message)) {
            return app('flash');
        }

        return app('flash')->info($message, $data);
    }
}

<?php

namespace App\Services\Foundation;

use Illuminate\Session\Store;
use Illuminate\Support\Collection;

/**
 * Register it in AppServiceProvider (or other): $this->app->singleton([FlashMessageSender::class => 'flash']);
 */
class FlashMessageSender
{
    const OLD_FLASH_LARAVEL_SESSION_ENGINE_KEY = '_flash.old';

    protected $keyInStorage = '_flash_messages';

    /**
     * @var \Illuminate\Session\Store
     */
    protected $session;

    /**
     * @var \Illuminate\Support\Collection
     */
    protected $messages;

    /**
     * @param \Illuminate\Session\Store $session
     */
    public function __construct(Store $session)
    {
        $this->session = $session;
        $this->messages = new Collection();
        $this->ageFlash();
    }

    /**
     * Set specific key for session storage.
     *
     * @param string $key
     */
    public function setStorageKey($key)
    {
        $this->keyInStorage = $key;
    }

    /**
     * Flash an information message.
     *
     * @param string $message
     * @param array $data
     * @return object
     */
    public function info($message, array $data = [])
    {
        return $this->addMessage($message, 'info', $data);
    }

    /**
     * Flash a success message.
     *
     * @param string $message
     * @param array $data
     * @return object
     */
    public function success($message, array $data = [])
    {
        return $this->addMessage($message, 'success', $data);
    }

    /**
     * Flash an error message.
     *
     * @param string $message
     * @param array $data
     * @return object
     */
    public function error($message, array $data = [])
    {
        return $this->addMessage($message, 'danger', $data);
    }

    /**
     * Flash a warning message.
     *
     * @param string $message
     * @param array $data
     * @return object
     */
    public function warning($message, array $data = [])
    {
        return $this->addMessage($message, 'warning', $data);
    }

    /**
     * Flash a general message.
     *
     * @param string $message
     * @param string $level
     * @param array $data
     * @return object
     */
    public function addMessage($message, $level = 'info', array $data = [])
    {
        $msg_object = (object) array_merge($data, ['text' => $message, 'level' => $level]);

        $this->messages->prepend($msg_object);

        $this->flash();

        return $msg_object;
    }

    /**
     * Return collection messages by level or all.
     *
     * @param string|null $level
     * @return \Illuminate\Support\Collection
     */
    public function getMessages($level = null)
    {
        $this->flushFlash();

        $messages = array_merge(
            $this->session->get($this->keyInStorage, []),
            $this->session->get($this->keyInStorage . '_old', [])
        );

        $messages = (new Collection($messages))->map(function ($message) {
            return (object) $message;
        });

        if (null === $level) {
            return $messages;
        }

        return $messages->filter(function ($message) use ($level) {
            return $message->level === $level;
        });
    }

    /**
     * Alias for getMessages method.
     *
     * @param string|null $level
     * @return \Illuminate\Support\Collection
     */
    public function messages($level = null)
    {
        return $this->getMessages($level);
    }

    /**
     * Store current messages to flash session store.
     */
    protected function flash()
    {
        $data = $this->messages
            ->map(function ($message) {
                return (array) $message;
            })
            ->toArray();

        $this->session->flash($this->keyInStorage, $data);
    }

    /**
     * Remove old messages to special message list.
     */
    protected function ageFlash()
    {
        if (! $this->session->has($this->keyInStorage)) {
            return;
        }

        $old_messages = $this->session->pull($this->keyInStorage);
        $key_old = $this->keyInStorage . '_old';
        $this->session->put($key_old, $old_messages);
        $this->session->push(self::OLD_FLASH_LARAVEL_SESSION_ENGINE_KEY, $key_old);
    }

    /**
     * Mark notices as old.
     */
    protected function flushFlash()
    {
        $this->session->push(self::OLD_FLASH_LARAVEL_SESSION_ENGINE_KEY, $this->keyInStorage);
    }
}