抽象类说它没有找到

Question

我正在尝试使用以下的抽象类，我收到一个错误说：

  

Class'Acme \ Transformers \ LessonTransformer'不存在。

我还添加了控制器类，以防可能出现问题。有谁能让我知道我在这里俯瞰什么？

LessonTransformer

<?php

namespace Acme\Transformers;

class LessonTransformer extends Transformer {

    public function transform($lesson){

        return [

            'title'=> $lesson['title'],

            'body' => $lesson['body'],

            'active' => (boolean) $lesson['some_bool']

        ];
    }
}

变压器

<?php

namespace Acme\Transformers;

abstract class Transformer{

    public function transformCollection($items){

        return array_map([$this, 'transform'], $items);

    }

    abstract public function transform($item);
}

LessonsController

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\Acme\Transformers\LessonTransformer;
use App\Lesson as Lesson;

class LessonsController extends Controller
{

    protected $lessonTransformer;

    function __construct(LessonTransformer $lessonTransformer){

        $this->lessonTransformer = $lessonTransformer;

    }

    /**
     * Display a listing of the resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function index()
    {
        // 1. All is bad
        // 2. No way to attach meta data
        // 3. Linking the Db structure to api output
        // 4. No way to signal headers or response codes
        // return Lesson::all();

        $lessons = Lesson::all();
        return response()->json([
            'data' => $this->lessonTransformer->transformCollection($lessons->all())
        ], 200);
    }

    /**
     * Show the form for creating a new resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function create()
    {
        //
    }

    /**
     * Store a newly created resource in storage.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return \Illuminate\Http\Response
     */
    public function store(Request $request)
    {
        //
    }

    /**
     * Display the specified resource.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function show($id)
    {
        $lesson = Lesson::find($id);

        if(!$lesson){
            return response()->json([

            'error' => [
                'message' => 'lesson does not exist'
            ]

            ], 404);
        }

        return response()->json([

            'data' => $this->lessonTransformer->transform($lesson)

        ],200);
    }

    /**
     * Show the form for editing the specified resource.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function edit($id)
    {
        //
    }

    /**
     * Update the specified resource in storage.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function update(Request $request, $id)
    {
        //
    }

    /**
     * Remove the specified resource from storage.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function destroy($id)
    {
        //
    }

}

composer.json

{
    "name": "laravel/laravel",
    "description": "The Laravel Framework.",
    "keywords": ["framework", "laravel"],
    "license": "MIT",
    "type": "project",
    "require": {
        "php": "^7.1.3",
        "fideloper/proxy": "^4.0",
        "fzaninotto/faker": "^1.7",
        "laravel/framework": "5.6.*",
        "laravel/tinker": "^1.0"
    },
    "require-dev": {
        "filp/whoops": "^2.0",
        "mockery/mockery": "^1.0",
        "nunomaduro/collision": "^2.0",
        "phpunit/phpunit": "^7.0"
    },
    "autoload": {
        "classmap": [
            "database/seeds",
            "database/factories",
            "app/acme"
        ],
        "psr-4": {
            "App\\": "app/"
        }
    },
    "autoload-dev": {
        "psr-4": {
            "Tests\\": "tests/"
        }
    },
    "extra": {
        "laravel": {
            "dont-discover": [
            ]
        }
    },
    "scripts": {
        "post-root-package-install": [
            "@php -r \"file_exists('.env') || copy('.env.example', '.env');\""
        ],
        "post-create-project-cmd": [
            "@php artisan key:generate"
        ],
        "post-autoload-dump": [
            "Illuminate\\Foundation\\ComposerScripts::postAutoloadDump",
            "@php artisan package:discover"
        ]
    },
    "config": {
        "preferred-install": "dist",
        "sort-packages": true,
        "optimize-autoloader": true
    },
    "minimum-stability": "dev",
    "prefer-stable": true
}

Answer 1

不应该

use App\Acme\Transformers\LessonTransformer;

是这个

use Acme\Transformers\LessonTransformer;

...

Answer 2

您已在以下命名空间下定义了变换器类：

namespace Acme\Transformers;

但您要导入LessonTransformer：

use App\Acme\Transformers\LessonTransformer

哪个是不同的命名空间。所以你需要修改它：

use Acme\Transformers\LessonTransformer