trantor/database.go

package main

import (
	"labix.org/v2/mgo"
	"labix.org/v2/mgo/bson"
)

type Book struct {
	Id          string `bson:"_id"`
	Title       string
	Author      []string
	Contributor string
	Publisher   string
	Description string
	Subject     []string
	Date        string
	Lang        []string
	Type        string
	Format      string
	Source      string
	Relation    string
	Coverage    string
	Rights      string
	Meta        string
	Path        string
	Cover       string
	CoverSmall  string
	Keywords    []string
}

/* optional parameters: length and start index
 * 
 * Returns: list of books, number found and err
 */
func GetBook(coll *mgo.Collection, query bson.M, r ...int) (books []Book, num int, err error) {
	var start, length int
	if len(r) > 0 {
		length = r[0]
		if len(r) > 1 {
			start = r[1]
		}
	}
	q := coll.Find(query)
	num, err = q.Count()
	if err != nil {
		return
	}
	if start != 0 {
		q = q.Skip(start)
	}
	if length != 0 {
		q = q.Limit(length)
	}

	err = q.All(&books)
	for i, b := range books {
		books[i].Id = bson.ObjectId(b.Id).Hex()
	}
	return

}