huacnlee/go-nested-set

go-nested-set is an Golang implementation of the Nested set model for GORM

Go Nested Set

Go Nested Set is an implementation of the Nested set model for Gorm.

This project is the Go version of awesome_nested_set, which uses the same data structure design, so it uses the same data together with awesome_nested_set.

Actually the original design is for this, the content managed by awesome_nested_set in our Rails application, the front-end Go API also needs to be maintained.

This is a Go version of the awesome_nested_set, and it built for compatible with awesome_nested_set, so you can use

Installation

go get github.com/griffinqiu/go-nested-set

Usage

Define the model

You must use nestedset Stuct tag to define your Gorm model like this:

Support struct tags:

• id - int64 - Primary key of the node
• parent_id - int64 - ParentID column, 0 is root
• lft - int
• rgt - int
• depth - int - Depth of the node
• children_count - Number of children

Example:

import "github.com/griffinqiu/go-nested-set"

// Category
type Category struct {
	ID            int64  `gorm:"PRIMARY_KEY;AUTO_INCREMENT" nestedset:"id"`
	Title         string
	ParentID      int64  `nestedset:"parent_id"`
	UserType      string `nestedset:"scope"`
	UserID        int64  `nestedset:"scope"`
	Rgt           int    `nestedset:"rgt"`
	Lft           int    `nestedset:"lft"`
	Depth         int    `nestedset:"depth"`
	ChildrenCount int    `nestedset:"children_count"`
}

Move Node

import nestedset "github.com/griffinqiu/go-nested-set"

// nestedset.MoveDirectionLeft
// nestedset.MoveDirectionRight
// nestedset.MoveDirectionInner
nestedset.MoveTo(tx, node, to, nestedset.MoveDirectionLeft)

Get Nodes with tree order

// With scope, limit tree in a scope
tx := db.Model(&Category{}).Where("user_type = ? AND user_id = ?", "User", 100)

// Get all nodes
categories, _ := tx.Order("lft asc").Error

// Get root nodes
categories, _ := tx.Where("parent_id IS NULL").Order("lft asc").Error

// Get childrens
categories, _ := tx.Where("parent_id = ?", parentCategory.ID).Order("lft asc").Error

Testing

$ createdb nested-set-test
$ go test ./...

License

MIT