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Gin Web Framework

Bind query string or post data

ShouldBind automatically selects the binding engine based on the HTTP method and Content-Type header:

  • For GET requests, it uses query string binding (form tags).
  • For POST/PUT requests, it checks the Content-Type — using JSON binding for application/json, XML for application/xml, and form binding for application/x-www-form-urlencoded or multipart/form-data.

This means a single handler can accept data from both query strings and request bodies without manual source selection.

package main


import (
  "log"
  "net/http"
  "time"


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


type Person struct {
  Name     string    `form:"name"`
  Address  string    `form:"address"`
  Birthday time.Time `form:"birthday" time_format:"2006-01-02" time_utc:"1"`
}


func main() {
  route := gin.Default()
  route.GET("/testing", startPage)
  route.POST("/testing", startPage)
  route.Run(":8085")
}


func startPage(c *gin.Context) {
  var person Person
  if err := c.ShouldBind(&person); err != nil {
    c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
    return
  }


  log.Printf("Name: %s, Address: %s, Birthday: %s\n", person.Name, person.Address, person.Birthday)
  c.JSON(http.StatusOK, gin.H{
    "name":     person.Name,
    "address":  person.Address,
    "birthday": person.Birthday,
  })
}

Test it

Terminal window
# GET with query string parameters
curl "http://localhost:8085/testing?name=appleboy&address=xyz&birthday=1992-03-15"
# Output: {"address":"xyz","birthday":"1992-03-15T00:00:00Z","name":"appleboy"}


# POST with form data
curl -X POST http://localhost:8085/testing \
  -d "name=appleboy&address=xyz&birthday=1992-03-15"
# Output: {"address":"xyz","birthday":"1992-03-15T00:00:00Z","name":"appleboy"}


# POST with JSON body
curl -X POST http://localhost:8085/testing \
  -H "Content-Type: application/json" \
  -d '{"name":"appleboy","address":"xyz","birthday":"1992-03-15"}'
# Output: {"address":"xyz","birthday":"1992-03-15T00:00:00Z","name":"appleboy"}

See also