Reading QueryArray from Gin golang

Question

Hi I am passing a query parameter to my gin server like this:

curl -X POST \
'http://localhost:4000/url?X=val1&Y=val2&x[]=1&x[]=2'

This is then sent to the my gin handler function

func handler (c *gin.Context) {
    fmt.Println(c.Query("X"))
    fmt.Println(c.Query("Y"))
    fmt.Println(c.QueryArray("x"))
}

While c.Query("x") and c.Query("Y") works, c.QueryArray("x") does not work!

I am not sure what am I missing over here. I have tried the same with GET request as well and it does not work.

Other experiments that did not work for me are here:

fmt.Println(c.Params.Get("x"))
fmt.Println(c.Params.Get("gene"))
fmt.Println(c.PostFormArray("x"))

Can you try this `curl -X POST 'http://localhost:4000/url?X=val1&Y=val2&x=1&x=2'`? — jeevatkm, Jun 12 '17 at 19:51
Are you sure this is POST request? You do not have post body. — jeevatkm, Jun 12 '17 at 19:53
The same [issue](https://github.com/gin-gonic/gin/issues/1516#issuecomment-544267410) with solution in gin repo. — Igor, Jun 14 '22 at 14:39

score 9 · Accepted Answer · answered Jun 12 '17 at 20:22

9

Drafted answer from my comment for SO users.

Repeat field name with values:

curl -X POST 'http://localhost:4000/url?X=val1&Y=val2&x=1&x=2'

or:

Separated by commas:

curl -X POST 'http://localhost:4000/url?X=val1&Y=val2&x=1,2'

answered Jun 12 '17 at 20:22

jeevatkm

4,571
1
23
24

score 0 · Answer 2 · answered Oct 16 '20 at 11:55

This maybe over-engineered, but it got things done for me:

// @Param property_type query []uint32 false "property_types"
func (svc *HttpService) acceptListofQuery(c *gin.Context) {
    var propertyTypes []uint32
    propertyTypes, done := svc.parsePropTypes(c)
    if done {
        return
    }
    // ..... rest of logic here
    c.JSON(200, "We good")
}

func (svc *HttpService) parsePropTypes(c *gin.Context) ([]uint32, bool) {
    var propertyTypes []uint32
    var propertyTypesAsString string
    var propertyTypesAsArrayOfStrings []string
    propertyTypesAsString, success := c.GetQuery("property_types")
    propertyTypesAsArrayOfStrings = strings.Split(propertyTypesAsString, ",")
    if success {
        for _, propertyTypeAsString := range propertyTypesAsArrayOfStrings {
            i, err := strconv.Atoi(propertyTypeAsString)
            if err != nil {
                svc.ErrorWithJson(c, 400, errors.New("invalid property_types array"))
                return nil, true
            }
            propertyTypes = append(propertyTypes, uint32(i))
        }
   }
    return propertyTypes, false
}

Then you can send something like:

curl -X POST 'http://localhost:4000/url?property_types=1,4,7,12

Reading QueryArray from Gin golang

2 Answers2