Multiple Location Write

• For Every function in FrostDelegate that modifies the database (add, update, delete) we have an equivalent getMap function.
• The equivalent getMap function returns an extra property (map) to the returned map from it's equivalent operation function (ie; add returns { id } ,getAddMap returns { id, map }). This map contains the update map that should be passed to the firebase update function.
• This allows us to utilize the multiple location writes feature in the firebaseDB.
• All you have to do is preform multiple operations and join the all of the maps and pass the joined map to the firebaseDB update function

Immediate operation	Equivalent getMap function
add	getAddMap
update	getUpdateMap
delete	getDeleteMap

info

Multiple location write can be very helpful in operating on collections. For example, if you want to delete a list of nodes; then you can achieve that by looping or (using array methods like map) on getDeleteMap instead of delete, then pass the final update map to update firebaseDB function.

Overcoming Limitations

• Firebase has a small limitation in Multi-Location writes, you can't have an update to a node and another separate update to a child of that node (ie; two updates to the same location with different paths).
• Frost has implemented a piece of code that overcomes this limitation. (This is specific to the Codegen versions)
• In the example below:
  • Lines 7-20: These lines should throw an error if you're using plain firebaseSDK because the final update map will have the path to set the user node, And each post add will also result in a update path inside that same user node (in order to connect them by setting ID values in the user node.). But because Frost's goal is to simplify dealing with the database as much as possible; these lines won't throw na error

src/index.ts

import { User, Post } from "@frost-orm/frost-web-client"import { FrostApp } from "src/data/frost"import { update } from "firebase/database";const user: User = {...}const { id: userId, map: addUserMap } = (await FrostApp.user.getAddMap(user))const post_1: Post= {...}const post_2: Post = {...}const {id:postId_1, map: addPostMap_1} = await FrostApp.post.getAddMap(post_1,{'user':userId})const {id:postId_2, map: addPostMap_2} = await FrostApp.post.getAddMap(post_2,{'user':userId})await update({  ...addUserMap,  ...addPostMap_1,  ...addPostMap_2,})