rail 在controller里面修改params

参考地址

# 传入参数进行secure params处理
def trip_params
  params.require(:trip).permit(:name, :date)
end

# 然后使用时想要修改参数值
def save
  trip_params[:name] = 'Modifying name in place'
  #trip_params[:name] 仍然是原来的值
end

原因：
permit returns a new hash with those keys in it, so you’re not modifying the real params variable. You’re also not saving a reference to the hash trip_params returns, so you get it fresh each call in save.
可以改为：

def save
  tp = trip_params
  tp[:name] = 'Modifying name in place'
  # ... use tp later, it'll be in there
end