CODEWITHSUNDEEP
jsongo
KiwiJuicer
KiwiJuicer

Reputation: 1982

Golang: Router config in json file

I want to put my router config in an extern json config file like so:

{
  "routes": [
    {
      "name": "Index",
      "method": "GET",
      "pattern": "/",
      "handler": "Index"
    },
    {
      "name": "CountsIndex",
      "method": "GET",
      "pattern": "/counts",
      "handler": "CountsIndex"
    }
  ]
}

My related struct looks like so:

type Route struct {
    Name        string      `json:"name"`
    Method      string      `json:"method"`
    Pattern     string      `json:"pattern"`
    HandlerFunc http.HandlerFunc    `json:"handler"`
}

type Routes []Route

The Problem is the handlerFunc. When I get the config it will be a string but how to make it a go value? Can I cast it somehow?

Following error occures:

json: cannot unmarshal string into Go value of type http.HandlerFunc

Thanks

Upvotes: 0

Views: 1000

Answers (2)

Alessio
Alessio

Reputation: 2068

The simplest solution is to have a string instead of the http.HandlerFunc as type, and define a map with the functions.

var functions = map[string]interface{}{
    "func1": func1,
}

then after unmarshalling your json you can assign the handler using the handlername of each route

Upvotes: 4

lofcek
lofcek

Reputation: 1233

The problem is, that not every data could be marshaled to json (or unmarshaled). http.HandlerFunc is not a function (https://golang.org/pkg/net/http/#HandlerFunc). You cannot put it directly - but you can change handler to string and on the place when you trying to call it obtain HandlerFunc from reflect (a quite complicated) or from prepared map[string]HandlerFunc.

Upvotes: 2

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