错误错误：“错误试图区分‘[对象]’。只允许数组和可迭代性(API Laravel和前端角7)。

Question

我正在使用Laravel中的JSON响应，但返回不是数组。我要做什么？有人能指点吗？我搞错了，弄不明白为什么？？下面是代码

拉勒维尔

public function show($id)
    {

        $arCategoria = \App\Favorito::join('categoria', 'categoria.cd_categoria', '=', 'link.cd_categoria')
        ->select('*')
        ->where('categoria.cd_categoria_pai',$id)
        ->where('link.cd_usuario',$this->token['cd_usuario'])
        ->where('link.bo_ativo',true)
            ->get();
        $link = $this->processarCategoria($arCategoria);
        return $link;
    }
    public function processarCategoria($arCategoria){
        $ar = array();
        $cont = 0;
        foreach($arCategoria as $key => $value){
            $ar[$value['no_categoria'].'_'.$value['cd_categoria']][] =  array(
                'no_link'=>$value['no_link'],
                'cd_link'=>$value['cd_link'],
                'vl_link'=>$value['vl_link'],
                'bo_ativo'=>$value['bo_ativo'],
                'link'=>$value['link']
            );

           $cont++;
        }

        return $ar;
    }

我返回的拉拉api

{
    "Documentation_3": [
        {
            "no_link": "stackoverflow",
            "cd_link": 5,
            "vl_link": null,
            "bo_ativo": 1,
            "link": "https://stackoverflow.com"
        },
        {
            "no_link": "Adventures of Time",
            "cd_link": 9,
            "vl_link": null,
            "bo_ativo": 1,
            "link": "http://adventuresoftime.com.br"
        }
    ],
    "Things to buy_5": [
        {
            "no_link": "Games",
            "cd_link": 10,
            "vl_link": null,
            "bo_ativo": 1,
            "link": "Games.com.br"
        }
    ]
}

还有我的service.ts

getLinksByIdusuario(id:number):Observable<any[]> {
    return this.http.get<any[]>(`${API}/favorito/${id}`)
    .pipe(map((data: any) => data ), 
                catchError(error => { return throwError(error)})
          );
  }

component.ts

ngOnInit() {


    this.id = params['id'];
    this.homeService.getLinksByIdusuario(this.id)
    .subscribe(
      categorias => {
        this.categorias = categorias,
        console.log(this.categorias)
      }
    )
}

component.html

<div class="row">
    <div *ngFor="let categoria of categorias">
        {{categoria |json}} 
    </div>
</div>

​

我应该改变我的拉拉后端还是有角的前部？如何解决这个问题？

Answer 1

您正在尝试遍历一个对象，这在角2+ 4和5中是不可能的。

你们的一些选择：

1-请求后端将其转换为数组：

[
    {

     "key":"Documentation_3",
     "value": [
        {
            "no_link": "stackoverflow",
            "cd_link": 5,
            "vl_link": null,
            "bo_ativo": 1,
            "link": "https://stackoverflow.com"
        },
    ],
   },
   {   
      "key":"Things to buy_5",
       "value" : [
        {
            "no_link": "Games",
            "cd_link": 10,
            "vl_link": null,
            "bo_ativo": 1,
            "link": "Games.com.br"
        }
    ]

    }

]

2-您可以创建一个对象密钥管道，或者如果您有angular6+，则可以使用键值管道。

`<div *ngFor="let category of categorias | keyvalue">       {{category.key}}:{{category.value}} ===>> this is an array , so you need another loop here     </div>`