**** UPDATE ****
我不确定为什么,但是将所有内容移动到控制器 index() 方法中而不是将其放在 show() 方法中解决了这个问题。不知道为什么有效,但它确实有效。
原始问题:
无法弄清楚这里出了什么问题,我已经按照文档,尝试了变体等......仍然没有运气正确地完成这项工作。
型号 A:(幻灯片)
public function carousels() {
return $this->belongsToMany(Carousel::class)->withTimestamp()
}
型号 B:(旋转木马)
public function slides() {
return $this->belongsToMany(Slide::class)->withTimestamp()
}
数据透视表
--------------------------------------------------
|carousel_id | slide_id | created_at | updated_at|
--------------------------------------------------
从控制器:
public function show(Carosuel $carousels) {
$carousels = $carousel->with('slides)->get();
return view('myView', compact(['carousels']));
}
在下面的转储中,"幻灯片"不在集合的属性对象中;但是,它们位于关系对象中。我不确定这是否是正常行为,或者幻灯片数组是否应该在属性对象中。如果是后者,那么如何实现这一目标呢?
$caousels转储:
Collection {#1320 ▼
#items: array:20 [▼
0 => Carousel {#798 ▼
#fillable: array:4 [▶]
#connection: "mysql"
#table: null
#primaryKey: "id"
#keyType: "int"
+incrementing: true
#with: []
#withCount: []
#perPage: 15
+exists: true
+wasRecentlyCreated: false
#attributes: array:7 [▼
"id" => 1
"name" => "Prof. Andre Gerlach"
"category" => "Dr."
"active" => 0
"deleted_at" => null
"created_at" => "2018-04-07 21:10:52"
"updated_at" => "2018-04-07 21:10:52"
]
#original: array:7 [▶]
#changes: []
#casts: []
#dates: []
#dateFormat: null
#appends: []
#dispatchesEvents: []
#observables: []
#relations: array:1 [▼
"slides" => Collection {#1300 ▼
#items: array:5 [▼
0 => Slide {#1023 ▶}
1 => Slide {#1024 ▶}
2 => Slide {#1025 ▶}
3 => Slide {#1026 ▶}
4 => Slide {#1027 ▶}
]
}
]
#touches: []
+timestamps: true
#hidden: []
#visible: []
#guarded: array:1 [▶]
}
1 => Carousel {#799 ▶}
2 => Carousel {#800 ▶}
在视图中:
foreach($carousels as $carousel){
echo $carousel->name;
foreach($carousel->slides as $slide){
echo $slide->tag;
}
}
这抛出了E_ERROR Invalid argument supplied for foreach() in view
但是,如果我将其转换为数组,它可以工作。问题是我还需要对结果进行分页。一旦我这样做,幻灯片数组再次无法访问。
public function show(Carosuel $carousels) {
// This works - slides are available to me in the view
$carousels = $carousel->with('slides)->get()->toarray();
// This DOESN'T work - slides are not available to me in the view
$carousels = $carousel->with('slides)->paginate(6)->toarray();
return view('myView', compact(['carousels']));
}
转储为数组:
array:12 [▼
"current_page" => 1
"data" => array:6 [▼
0 => array:8 [▼
"id" => 1
"name" => "Prof. Andre Gerlach"
"category" => "Dr."
"active" => 0
"deleted_at" => null
"created_at" => "Apr 07 2018"
"updated_at" => "2018-04-07 21:10:52"
"slides" => array:5 [▼
0 => array:11 [▶]
1 => array:11 [▶]
2 => array:11 [▶]
3 => array:11 [▶]
4 => array:11 [▶]
]
]
1 => array:8 [▶]
2 => array:8 [▶]
3 => array:8 [▶]
4 => array:8 [▶]
5 => array:8 [▶]
]
"first_page_url" => "//localhost:3000/admin/carousel/show?page=1"
"from" => 1
"last_page" => 4
"last_page_url" => "//localhost:3000/admin/carousel/show?page=4"
"next_page_url" => "//localhost:3000/admin/carousel/show?page=2"
"path" => "//localhost:3000/admin/carousel/show"
"per_page" => 6
"prev_page_url" => null
"to" => 6
"total" => 20
这里的问题是,在视图中,幻灯片键不再可访问。抛出以下错误(仅当我使用->paginate()
时)。
E_ERROR Trying to get property 'slides' of non-object
我在文档和其他来源中阅读的所有内容都表明这是一个非常基本的操作。对于我的生活,我无法弄清楚为什么它会导致这样的问题。我应该能够通过简单地嵌套一个 foreach 来在视图中访问它。
任何这方面的帮助将不胜感激。
在下面的转储中,"幻灯片"不在集合的属性对象中;但是,它们位于关系对象中。
是的,这是正常的。
这是您遇到问题的地方:
public function show(Carosuel $carousels) {
// ...
return view('myView', compact(['carousels']));
}
在函数中键入模型是为模型绑定保留的。这不是您在这里要做的事情,因为您的路线中没有{id}
或其他参数。
删除类型提示并改为调用模型:
public function show() {
$carousels = Carousel::with('slides')->get();
return view('myView', compact(['carousels']));
}
如果要从方法中删除依赖项,则应改为在构造函数中执行此操作。
编辑:
虽然我没有看到任何其他问题并且上述解决方案应该有效,但如果->toArray()
确实适合您(但您仍然需要分页),您可以转换底层集合:
public function show() {
$carousels = Carousel::with('slides')->paginate();
$carousels->setCollection(collect($carousels->getCollection()->toArray()));
return view('myView', compact(['carousels']));
}
你能试试这个吗?
型号 B:(旋转木马)
public function slides() {
return $this->hasMany(Slide::class)->withTimestamp();
}