ruby-on-rails – 强参数中嵌套对象中的Rails 4嵌套数组

我的问题：如何在嵌套对象中允许嵌套数组？我有一个带有has_many功能的贡献模型.我正在尝试创建GeoJSON多边形.
坐标保持空白

这是我发送的JSON

{
  "contribution": {
    "features_attributes": [
      {
        "geojson": {
          "type": "Feature","properties": {},"geometry": {
            "type": "Polygon","coordinates": [
              [
                [
                  7.263336181640625,52.07190953840937
                ],[
                  7.263336181640625,52.135173926548894
                ],[
                  7.404785156249999,52.07190953840937
                ]
              ]
            ]
          }
        }
      }
    ],"title": "324","description": "23"
  }
}

目前我的许可证代码如下所示：

params.require(:contribution).permit(
  :title,:description,features_attributes: [
    { geojson: [
        :type,{ geometry: [
            :type,#{ coordinates: [] } # this works for arrays like coordinates: [ 7.62,51.96 ]
            { coordinates: [[]] }
          ]
        }
      ]
    }
  ]
)