mongopagination

README

Golang Mongo Pagination For Package mongo-go-driver

For all your simple query to aggregation pipeline this is simple and easy to use Pagination driver with information like Total, Page, PerPage, Prev, Next, TotalPage and your actual mongo result.

Install

$ go get -u -v github.com/gobeam/mongo-go-pagination

or with dep

$ dep ensure -add github.com/gobeam/mongo-go-pagination

For Aggregation Pipelines Query

package main

import (
	"context"
	"fmt"
	. "github.com/gobeam/mongo-go-pagination"
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/bson/primitive"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
	"time"
)

type Product struct {
	Id       primitive.ObjectID `json:"_id" bson:"_id"`
	Name     string             `json:"name" bson:"name"`
	Quantity float64            `json:"qty" bson:"qty"`
	Price    float64            `json:"price" bson:"price"`
}

func main() {
	// Establishing mongo db connection
	ctx, _ := context.WithTimeout(context.Background(), 10*time.Second)
	client, err := mongo.Connect(ctx, options.Client().ApplyURI("mongodb://localhost:27017"))
	if err != nil {
		panic(err)
	}
	
	var limit int64 = 10
	var page int64 = 1
	collection := client.Database("myaggregate").Collection("stocks")

	//Example for Aggregation

	//match query
	match := bson.M{"$match": bson.M{"qty": bson.M{"$gt": 10}}}

	//group query
	projectQuery := bson.M{"$project": bson.M{"_id": 1, "qty": 1}}

	// you can easily chain function and pass multiple query like here we are passing match
	// query and projection query as params in Aggregate function you cannot use filter with Aggregate
	// because you can pass filters directly through Aggregate param
	aggPaginatedData, err := New(collection).Limit(limit).Page(page).Aggregate(match, projectQuery)
	if err != nil {
		panic(err)
	}

	var aggProductList []Product
	for _, raw := range aggPaginatedData.Data {
		var product *Product
		if marshallErr := bson.Unmarshal(raw, &product); marshallErr == nil {
			aggProductList = append(aggProductList, *product)
		}

	}

	// print ProductList
	fmt.Printf("Aggregate Product List: %+v\n", aggProductList)

	// print pagination data
	fmt.Printf("Aggregate Pagination Data: %+v\n", aggPaginatedData.Data)
}

For Normal queries

func main() {
	// Establishing mongo db connection
	ctx, _ := context.WithTimeout(context.Background(), 10*time.Second)
	client, err := mongo.Connect(ctx, options.Client().ApplyURI("mongodb://localhost:27017"))
	if err != nil {
		panic(err)
	}

	// Example for Normal Find query
    	filter := bson.M{}
    	var limit int64 = 10
    	var page int64 = 1
    	collection := client.Database("myaggregate").Collection("stocks")
    	projection := bson.D{
    		{"name", 1},
    		{"qty", 1},
    	}
    	// Querying paginated data
    	// Sort and select are optional
    	paginatedData, err := New(collection).Limit(limit).Page(page).Sort("price", -1).Select(projection).Filter(filter).Find()
    	if err != nil {
    		panic(err)
    	}
    
    	// paginated data is in paginatedData.Data
    	// pagination info can be accessed in  paginatedData.Pagination
    	// if you want to marshal data to your defined struct
    
    	var lists []Product
    	for _, raw := range paginatedData.Data {
    		var product *Product
    		if marshallErr := bson.Unmarshal(raw, &product); marshallErr == nil {
    			lists = append(lists, *product)
    		}
    
    	}
    	// print ProductList
    	fmt.Printf("Norm Find Data: %+v\n", lists)
    
    	// print pagination data
    	fmt.Printf("Normal find pagination info: %+v\n", paginatedData.Pagination)
}
    

Running the tests

$ go test

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

Acknowledgments

1. https://github.com/mongodb/mongo-go-driver

MIT License

Copyright (c) 2020

Documentation

Index

• Constants
• func Paging(p *pagingQuery, paginationInfo chan<- *Paginator, aggregate bool, ...)
• type AggregationData
• type AutoGenerated
• type FindData
• type PaginationData
• type Paginator
  • func (p *Paginator) PaginationData() *PaginationData
• type PagingQuery
  • func New(collection *mongo.Collection) PagingQuery

Constants

const (
	PageLimitError         = "page or limit cannot be less than 0"
	FilterInAggregateError = "you cannot use filter in aggregate query but you can pass multiple filter as param in aggregate function"
	NilFilterError         = "filter query cannot be nil"
)

Error constants

Functions

func Paging

func Paging(p *pagingQuery, paginationInfo chan<- *Paginator, aggregate bool, aggCount int64)

Paging returns Paginator struct which hold pagination stats

Types

type AggregationData

type AggregationData struct {
	Data       *mongo.Cursor  `json:"data"`
	Pagination PaginationData `json:"pagination"`
}

AggregationData struct holds data and pagination detail

type AutoGenerated

type AutoGenerated struct {
	Total []struct {
		Count int64 `json:"count"`
	} `json:"total"`
	Data []bson.Raw `json:"data"`
}

AutoGenerated is to bind Aggregate query result data

type FindData

type FindData struct {
	Data       []bson.Raw     `json:"data"`
	Pagination PaginationData `json:"pagination"`
}

type PaginationData

type PaginationData struct {
	Total     int64 `json:"total"`
	Page      int64 `json:"page"`
	PerPage   int64 `json:"perPage"`
	Prev      int64 `json:"prev"`
	Next      int64 `json:"next"`
	TotalPage int64 `json:"totalPage"`
}

PaginationData struct for returning pagination stat

type Paginator

type Paginator struct {
	TotalRecord int64 `json:"total_record"`
	TotalPage   int64 `json:"total_page"`
	Offset      int64 `json:"offset"`
	Limit       int64 `json:"limit"`
	Page        int64 `json:"page"`
	PrevPage    int64 `json:"prev_page"`
	NextPage    int64 `json:"next_page"`
}

Paginator struct for holding pagination info

func (*Paginator) PaginationData

func (p *Paginator) PaginationData() *PaginationData

PaginationData returns PaginationData struct which holds information of all stats needed for pagination

type PagingQuery

type PagingQuery interface {
	// Find set the filter for query results.
	Find() (paginatedData *FindData, err error)

	Aggregate(criteria ...interface{}) (paginatedData *AggregationData, err error)

	// Select used to enable fields which should be retrieved.
	Select(selector interface{}) PagingQuery

	Filter(selector interface{}) PagingQuery
	Limit(limit int64) PagingQuery
	Page(page int64) PagingQuery
	Sort(sortField string, sortValue int) PagingQuery
}

PagingQuery is an interface that provides list of function you can perform on pagingQuery

func New

func New(collection *mongo.Collection) PagingQuery

New is to construct PagingQuery object with mongo.Database and collection name