Unable to validate both query parameters and request body using a single struct in Gin application

[Manojnaik1]

Description

I am facing an issue where I am unable to validate both query parameters and the request body using a single struct in my Gin application. Currently, the ShouldBind method only validates the request body, while query parameters are not being validated.

Steps to Reproduce:
Define a struct, FlowRequest, to represent the request data:
type FlowRequest struct {
TenantID int json:"tenant_id" uri:"tenantID" binding:"required"
Name string json:"name" binding:"required"
}

Use the FlowRequest struct in the Gin handler function:
func handleRequest(c *gin.Context) {
var req FlowRequest

if err := c.ShouldBind(&req); err != nil {
    c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
    return
}

// Process the request and return the response
c.JSON(http.StatusOK, gin.H{"message": "Request processed successfully"})

}

Make a request to the API endpoint with both the path parameter tenantID and the request body containing name:
POST /api/flow/123
Content-Type: application/json

{
"name": "John Doe"
}

Observe that the validation for the Name field in the request body is working correctly, but the TenantID path parameter is not being validated.

Expected Behavior
I expect both the query parameters and the request body to be validated according to the defined struct tags.

Actual Behavior
Only the request body is being validated, while query parameters are not being validated.

Environment
go version: go1.20.4
Please let me know if there are any further details or modifications you would like to make to the issue description.

[AhmadGhadiri]

I think for validating the param and body, a single function/struct combo can not be used. The ShouldBindUri function can be used per this PR #1612
Something like this worked for me:

// Used for validating params in URI
type RequestUri struct {
	TenantID int `uri:"tenant_id" binding:"required"`
}

// Used for Body 
type RequestBody struct {
	Name string `json:"name" binding:"required"`
}

func main() {
	g := gin.Default()
	g.POST("/api/flow/:tenant_id", func(c *gin.Context) {
		var uri RequestUri
		var body RequestBody
		if err := c.ShouldBindUri(&uri); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		} else if err := c.ShouldBind(&body); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		} else {
			c.JSON(http.StatusOK, gin.H{"message": fmt.Sprintf("Hello %v, this is the id: %v", body.Name, uri.TenantID)})
		}
	})
	g.Run(":9000")
}