Question

我要做的是循环哈希并将某些键的值保存到数据库中。这个哈希有嵌套键，我很难找到一种合适的方法来循环它。

首先，我正在解析照片的JSON（来自500px API），并将响应放入终端：

def index
  @photos = JSON.parse(get_access_token.get('/v1/photos/search?term=california').body)
  p @photos
  save @photos
end

我在控制台中得到的响应都没问题，看起来像这样。（我把它剪掉了所以不占用太多空间）：

{
  "current_page": 1,
  "total_pages": 50,
  "total_items": 8263,
  "photos": [
    {
      "id": 4930535,
      "name": "Bike",
      "description": "",
      "times_viewed": 28,
      "rating": 27,
      "created_at": "2012-02-10T00:39:03-05:00"
    },
    {
      "id": 4930206,
      "name": "Rain",
      "description": "",
      "times_viewed": 1,
      "rating": 59.7,
      "created_at": "2012-02-10T00:04:09-05:00"
    },
    {
      "id": 4930202,
      "name": "California",
      "description": "",
      "times_viewed": 100,
      "rating": 58.2,
      "created_at": "2012-02-10T00:05:25-05:00"
    }
  ]
}

然后我尝试遍历photos并使用此保存方法将name，description和times_viewed保存到数据库。

def save photos

  photos.each do |photo|
    p = Photo.new(:name => photo["photos"]["name"], :description => photo["photos"]["description"], :times_viewed => photo["photos"]["times_viewed"])
    p.save
  end

end

问题是照片键是嵌套的，它会在终端中抛出此错误：

TypeError (no implicit conversion of String into Integer):
  app/controllers/photos_controller.rb:18:in `[]'
  app/controllers/photos_controller.rb:18:in `block in save'
  app/controllers/photos_controller.rb:17:in `each'
  app/controllers/photos_controller.rb:17:in `save'
  app/controllers/photos_controller.rb:10:in `index'

Answer 1

只需从你的json响应中取出照片数组并迭代它。这样，您只需要一层哈希键来引用：

json_response['photos'].each do |photo|
  Photo.create name: photo['name'], description: photo['description'], 
    times_viewed: photo['times_viewed']
end

Answer 2

photos["photos"]是一个数组，因此您需要在name之前指定索引。保存方法的实现并不完全清楚，但我相信新方法的参数应该采用以下形式：

:name => photo["photos"][index]["name"]

由于编译器尝试将name转换为索引，因此您收到转换错误。

在Rails控制器中循环嵌套哈希

2 个答案: