gogjango/gjango

package request

import (
    "net/http"
    "strconv"

    "github.com/gin-gonic/gin"
    "github.com/gogjango/gjango/apperr"
)

const (
    defaultLimit = 100
    maxLimit     = 1000
)

// Pagination contains pagination request
type Pagination struct {
    Limit  int `form:"limit"`
    Page   int `form:"page" binding:"min=0"`
    Offset int `json:"-"`
}

// Paginate validates pagination requests
func Paginate(c *gin.Context) (*Pagination, error) {
    p := new(Pagination)
    if err := c.ShouldBindQuery(p); err != nil {
        apperr.Response(c, err)
        return nil, err
    }
    if p.Limit < 1 {
        p.Limit = defaultLimit
    }
    if p.Limit > 1000 {
        p.Limit = maxLimit
    }
    p.Offset = p.Limit * p.Page
    return p, nil
}

// ID returns id url parameter.
// In case of conversion error to int, request will be aborted with StatusBadRequest.
func ID(c *gin.Context) (int, error) {
    id, err := strconv.Atoi(c.Param("id"))
    if err != nil {
        c.AbortWithStatus(http.StatusBadRequest)
        return 0, apperr.BadRequest
    }
    return id, nil
}