将map [string] interface {}转换为有效的Mongo查询

Question

I am currently receiving a mongo aggregate query from a payload:

[
  {
    "$match": {
      "isComplete": true
      "accountId": "foo123"
      "startTime": "2017-03-06T23:07:21.262Z"
      "$or": [ { userId: "bar123" }, { userId: "bar235" } ]
    } 
  },
  {
    "$group": {
      "_id": null,
      "count": {
        "$sum": 1
      }
    }
  }
]

This is being stored as a map[string]interface{}. The issue is the $match clause can be any arbitrary query, which means it can contain ObjectIds and Dates. I have tried manually converting ids to bson.ObejectIds and any Dates to time.Times but the queries can become very complicated.

Does anyone know any good way of taking an arbitrary mongo query from a payload and converting it?

Answer 1

It seems like you need to unmarshaling to a []map[string]interface{} with that array structure in the post.

With that being said you can do something like this (with the currect map[string]interface{} type.

type Payload struct {
    Message map[string]interface{} `json:"message"`
}

// If you are using it as a http HandleFunc
func (s *Server) ProcessPayload() {
    PayloadHandler := func(w http.ResponseWriter, r *http.Request) {
        incoming := r.FormValue("message")
        if incoming != "" {
            var payload = new(Payload)
            json.Unmarshal([]byte(incoming), payload)

            go payload.FromPayload()
        }
    }

    http.HandleFunc("/payload", PayloadHandler)
}

func (p *Payload) FromPayload() {
    match, ok := p.Message["$match"]
    if !ok {
        return
    }
    // Do your work on the $match object
}