bootTraits实现捕捉模型字段变动

源码Illuminate\Database\Eloquent\Model中bootTraits方法可以自定义模型启动后做一些处理

   protected static function bootTraits()
    {
        $class = static::class;
        $booted = [];
        static::$traitInitializers[$class] = [];
        foreach (class_uses_recursive($class) as $trait) {
            $method = 'boot'.class_basename($trait);//关键语句
            if (method_exists($class, $method) && ! in_array($method, $booted)) {
                forward_static_call([$class, $method]);
                $booted[] = $method;
            }
            if (method_exists($class, $method = 'initialize'.class_basename($trait))) {
                static::$traitInitializers[$class][] = $method;
                static::$traitInitializers[$class] = array_unique(
                    static::$traitInitializers[$class]
                );
            }
        }
    }

实现步骤

一 注册模型启动任务

trait FieldLogTrait
{
    public static function bootFieldLogTrait()
    {
        static::saved(function ($model) {
                $_model            = clone $model;
                $_model->relations = [];
                FieldLog::addEvent(function () use ($_model) {
                    return $_model->changedRevisionableFields();
                });
            });
        static::deleted(function ($model) {
            $_model            = clone $model;
            $_model->relations = [];
            FieldLog::addEvent(function () use ($_model) {
                return $_model->changedRevisionableFields();
            });
        });
    }
   private function changedRevisionableFields()
    {
        $changes_to_record = [];
        $dirtyData         = $this->getDirty();
        $originalData      = $this->original;
        $updatedData       = $this->attributes;
        $table             = $this->getTable();
        $row_id            = $this->getKey();
        foreach ($dirtyData as $key => $value) {
                if (!isset($originalData[$key]) || $originalData[$key] != $updatedData[$key]) {
                    $old_value           = array_get($originalData, $key);
                    $changes_to_record[] = [
                        'table'     => $table,
                        'row_id'    => $row_id,
                        'key'       => $key,
                        'old_value' => !empty($old_value) ? $old_value : '',
                        'new_value' => $updatedData[$key],
                    ];
                }
        }
        return $changes_to_record;
    }

二 字段变动收集

<?php
namespace App\Foundation\FieldLog;
use App\Foundation\RequestID\RequestID;
use App\Foundation\RequestID\ResID;
use Carbon\Carbon;
use Illuminate\Support\Facades\App;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Log;
use function MongoDB\select_server;
class FieldLogHandler
{
    /**
     * 是否保存
     * @var bool
     */
    public $canStore = true;
    /**
     * 保存请求之后执行的动作
     * @var array
     */
    public $events = [];
    /**
     * 保存修改记录
     */
    public function store()
    {
        if ($this->canStore) {
            try {
                if (!empty($this->events)) {
                    $data = [];
                    //执行并合并所有结果
                    foreach ($this->events as $event) {
                        $results = call_user_func($event);
                        if (!empty($results)) {
                            foreach ($results as $result) {
                                $data[] = $result;
                            }
                        }
                    }
                    //保存结果
                    if (!empty($data)) {
                        if (count($data) > 20) {
                            //防止insert过长
                            $lists = array_chunk($data, 20);
                            foreach ($lists as $list) {
                                $this->insert($list);
                            }
                        } else {
                            $this->insert($data);
                        }
                    }
                }
            } catch (\Exception $exception) {
            }
        }
    }
    /**
     * 业务完成之后执行的回调
     * @param callable $fn
     */
    public function addEvent(callable $fn)
    {
        $this->events[] = $fn;
    }
    /**
     * 跳过持久化
     */
    public function skip()
    {
        $this->canStore = false;
    }
    public function insert($data)
    {
        if (!empty($data)) {
            $time      = Carbon::now()->toDateTimeString();
            $requestId = ResID::get();
            foreach ($data as $key => $item) {
                $data[$key]['request_id'] = $requestId;
                $data[$key]['created_at'] = $time;
                $data[$key]               = array_merge($data[$key], $this->extra);
            }
            event(new FieldChangeEvent($data));
        }
    }
}

三 持久化

创建事件监听器处理FieldChangeEvent事件即可