laravel 修改 Eloquent 模型的自定义属性
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/43756564/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Modify a custom attribute of an Eloquent Model
提问by Lucian P.
I have a model which contain a custom attribute
我有一个包含自定义属性的模型
class Test extends Model
{
protected $appends = ['counter'];
public function getCounterAttribute()
{
return 1;
}
}
I need to change the value of the custom attribute, like:
我需要更改自定义属性的值，例如：
$tests = Test::all();
foreach ($tests AS $test) {
$test->counter = $test->counter + 100;
}
This does not work, which is the correct way to do it?
这不起作用，这是正确的方法吗？
采纳答案by LombaX
The problem is that your accessor returns always 1
问题是您的访问器总是返回 1
public function getCounterAttribute()
{
return 1;
}
Your loop sets correctly the counterattribute (inspectable via $model->attributes['counter']).
However, when you call $test->counterits value is resolved via the getCounterAttribute()method, that returns always 1.
您的循环正确设置了counter属性（可通过 进行检查$model->attributes['counter']）。但是，当您调用$test->counter它的值是通过该getCounterAttribute()方法解析时，它始终返回 1。
Update your getCounterAttribute()to something like this:
将您更新getCounterAttribute()为这样的内容：
public function getCounterAttribute()
{
return isset($this->attributes['counter']) ? $this->attributes['counter'] : 1;
}
this way, you are saying: "if the counter attribute is set, return it. Otherwise, return 1".
这样，您就是说：“如果设置了计数器属性，则返回它。否则，返回 1”。
回答by René
You'll need to define a mutator on your Test model:
你需要在你的测试模型上定义一个mutator：
public function setCounterAttribute($value)
{
$this->attributes['counter'] = value;
}
For more info: https://laravel.com/docs/5.4/eloquent-mutators#defining-a-mutator
更多信息：https: //laravel.com/docs/5.4/eloquent-mutators#defining-a-mutator
