github.com/vcraescu/go-paginator

Paginator

A simple way to implement pagination in Golang.

Usage

package main

import (
	"fmt"
	"github.com/jinzhu/gorm"
	_ "github.com/jinzhu/gorm/dialects/sqlite"
	"github.com/vcraescu/go-paginator"
	"github.com/vcraescu/go-paginator/adapter"
	"time"
)

type Post struct {
	ID          uint `gorm:"primary_key"`
	Title       string
	Body        string
	PublishedAt time.Time
}

func main() {
	db, err := gorm.Open("sqlite3", "my_db.db")
	if err != nil {
		panic(fmt.Errorf("db connection error: %s", err))
	}

	db.AutoMigrate(&Post{})
	
	var posts []Post
	
	q := db.Model(Post{}).Where("published_at > ?", time.Now())
	p := paginator.New(adapter.NewGORMAdapter(q), 10)
	p.SetPage(2)
	
	if err = p.Results(&posts); err != nil {
		panic(err)
	}
	
	for _, post := range posts {
		fmt.Println(post.Title)
	}
}

Some of other methods available:

p.HasNext()
p.HasPrev()
p.HasPages()
p.PageNums()

Adapters

An adapter must implement the Adapter interface which has 2 methods:

• Nums - must return the number of results;
• Slice - must retrieve a slice for an offset and length.

This way you can create your own adapter for any kind of data source you want to paginate.

type Adapter interface {
	Nums() int
	Slice(offset, length int, data interface{}) error
}

GORM Adapter

To paginate a GORM query builder.

q := db.Model(Post{}).Where("published_at > ?", time.Now())
p := paginator.New(adapter.NewGORMAdapter(q), 10)

Slice adapter

To paginate a slice.

var pages []int
p := paginator.New(adapter.NewSliceAdapter(pages), 10)

Views

View models contains all necessary logic to render the paginator inside a template.

DefaultView

Use it if you want to render a paginator similar to the one from Google search.

< Prev 2 3 4 5 6 7 8 9 10 11 Next >

func main() {
	db, err := gorm.Open("sqlite3", "my_db.db")
	if err != nil {
		panic(fmt.Errorf("db connection error: %s", err))
	}

	db.AutoMigrate(&Post{})
	
	var posts []Post
	
	q := db.Model(Post{}).Where("published_at > ?", time.Now())
	p := paginator.New(adapter.NewGORMAdapter(q), 10)
	p.SetPage(7)
	
	view := view.New(&p)
	
	fmt.Println(view.Pages()) // [2 3 4 5 6 7 8 9 10 11]
	fmt.Println(view.Next()) // 8
	fmt.Println(view.Prev()) // 6
	fmt.Println(view.Current()) // 7
}

TODO

• More adapters

License

Paginator is licensed under the MIT License.