blob: 8459c66d6473a966193f5b00220ec4ad76a07e68 [file] [log] [blame]
// Copyright 2017 Google Inc. All Rights Reserved.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.
package firestore
import (
// A CollectionRef is a reference to Firestore collection.
type CollectionRef struct {
c *Client
// Typically Parent.Path, or c.path if Parent is nil.
// May be different if this CollectionRef was created from a stored reference
// to a different project/DB.
parentPath string
// Parent is the document of which this collection is a part. It is
// nil for top-level collections.
Parent *DocumentRef
// The full resource path of the collection: "projects/P/databases/D/documents..."
Path string
// ID is the collection identifier.
ID string
// Use the methods of Query on a CollectionRef to create and run queries.
func newTopLevelCollRef(c *Client, dbPath, id string) *CollectionRef {
return &CollectionRef{
c: c,
ID: id,
parentPath: dbPath,
Path: dbPath + "/documents/" + id,
Query: Query{c: c, collectionID: id, parentPath: dbPath},
func newCollRefWithParent(c *Client, parent *DocumentRef, id string) *CollectionRef {
return &CollectionRef{
c: c,
Parent: parent,
ID: id,
parentPath: parent.Path,
Path: parent.Path + "/" + id,
Query: Query{c: c, collectionID: id, parentPath: parent.Path},
// Doc returns a DocumentRef that refers to the document in the collection with the
// given identifier.
func (c *CollectionRef) Doc(id string) *DocumentRef {
if c == nil {
return nil
return newDocRef(c, id)
// NewDoc returns a DocumentRef with a uniquely generated ID.
func (c *CollectionRef) NewDoc() *DocumentRef {
return c.Doc(uniqueID())
// Add generates a DocumentRef with a unique ID. It then creates the document
// with the given data, which can be a map[string]interface{}, a struct or a
// pointer to a struct.
// Add returns an error in the unlikely event that a document with the same ID
// already exists.
func (c *CollectionRef) Add(ctx context.Context, data interface{}) (*DocumentRef, *WriteResult, error) {
d := c.NewDoc()
wr, err := d.Create(ctx, data)
if err != nil {
return nil, nil, err
return d, wr, nil
const alphanum = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
var (
rngMu sync.Mutex
rng = rand.New(rand.NewSource(time.Now().UnixNano() ^ int64(os.Getpid())))
func uniqueID() string {
var b [20]byte
for i := 0; i < len(b); i++ {
b[i] = alphanum[rng.Intn(len(alphanum))]
return string(b[:])