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Gin Web Framework

Map as querystring or postform parameters

Sometimes you need to receive a set of key-value pairs where the keys are not known in advance — for example, dynamic filters or user-defined metadata. Gin provides c.QueryMap and c.PostFormMap to parse bracket-notation parameters (like ids[a]=1234) into a map[string]string.

  • c.QueryMap("key") — parses key[subkey]=value pairs from the URL query string.
  • c.PostFormMap("key") — parses key[subkey]=value pairs from the request body.
package main


import (
  "fmt"
  "net/http"


  "github.com/gin-gonic/gin"
)


func main() {
  router := gin.Default()


  router.POST("/post", func(c *gin.Context) {
    ids := c.QueryMap("ids")
    names := c.PostFormMap("names")


    fmt.Printf("ids: %v; names: %v\n", ids, names)
    c.JSON(http.StatusOK, gin.H{
      "ids":   ids,
      "names": names,
    })
  })


  router.Run(":8080")
}

Test it

Terminal window
curl -X POST "http://localhost:8080/post?ids[a]=1234&ids[b]=hello" \
  -d "names[first]=thinkerou&names[second]=tianou"
# Output: {"ids":{"a":"1234","b":"hello"},"names":{"first":"thinkerou","second":"tianou"}}

See also