Parse dynamic key in Json in Go

There is time, when we’re not sure what the key_name in json data will be. How do we do it in Go?

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We will use interface for the dynamic key.

For example the json value be like:

{
  "TRPV6": {
    "ncbi": {
      "symbol": "",
      "symbol_source": "",
      "id": "",
      "gene_name": "",
      "gene_synonyms": null,
      "biotype": "",
      "contig": "",
      "start": 0,
      "end": 0,
      "reference_genome": "",
      "strand": "",
      "description": ""
    },
    "ensembl": {
      "symbol": "TRPV6",
      "symbol_source": "ensembl_havana",
      "id": "ENSG00000165125",
      "gene_name": "TRPV6",
      "gene_synonyms": [
        "CaT1",
        "ECAC2"
      ],
      "biotype": "",
      "contig": "chr7",
      "start": 142871208,
      "end": 142885745,
      "reference_genome": "GRCh38",
      "strand": "-",
      "description": ""
    },
    "gene_cards": {
      "symbol": "",
      "id": "",
      "gene_name": "",
      "gene_synonyms": null,
      "biotype": "",
      "contig": "",
      "start": 0,
      "end": 0,
      "reference_genome": "",
      "strand": "",
      "description": null
    }
  }
}

The “TRPV6” key is the one which is constantly changed.

To get the key from the interface:

func Keys(m map[string]interface{}) []string {
   keys := make([]string, len(m))
   i := 0
   for k := range m {
      keys[i] = k
      i++
   }
   return keys
}

Running the Keys method will show the key of interface like

[OR4F5]

If we don’t want it to be so generic, we can apply the specific object type:

• UnMarshal

func (s ResultObject) UnmarshalJSON(data []byte)  map[string]Medium  {
   var z map[string]Medium

   if err := json.Unmarshal(data, &z); err != nil {
      fmt.Println(string(data[:]))
      panic(err)
   }
   return z
}

• Keys

func Keys(m map[string]gene.Medium) string {
   keys := make([]string, len(m))
   i := 0
   for k := range m {
      keys[i] = k
      i++
   }
   return keys[0]
}

The test code will be implemented like

line := scanner.Text()
listJsonEnsembl = append(listJsonEnsembl, line)
geneResult := gene.ResultObject{}

result := geneResult.UnmarshalJSON([]byte(line))
localKey := Keys(result)
fmt.Println(result[localKey].Ncbi.Name)

Hope it helps~~

PEACE!!!