Lifecycle Hooks

FireODM models support lifecycle callbacks (hooks) that run before or after various operations. Use these to:

• Set default values or timestamps
• Enforce business rules
• Trigger side effects (logging, analytics)

Supported Hooks

Hook	When It Runs	Signature
beforeSave	Before .save() (create or overwrite)	async beforeSave(options?: SetOptions)
afterSave	After .save()	async afterSave(result: WriteResult)
beforeUpdate	Before .update()	async beforeUpdate(data: UpdateData<T>)
afterUpdate	After .update()	async afterUpdate(result: WriteResult, data: UpdateData<T>)
beforeDelete	Before .delete()	async beforeDelete()
afterDelete	After .delete()	async afterDelete(result: WriteResult, originalId: string)
afterLoad	After loading via findById or converter	async afterLoad(snapshot: DocumentSnapshot)

Example: Auditing Fields

import { BaseModel, Collection, StringField, TimestampField } from 'fireodm'
import { Timestamp } from 'firebase-admin/firestore'

@Collection('posts')
class Post extends BaseModel {
    @StringField({ required: true })
    title!: string

    @TimestampField({ defaultNow: true })
    createdAt?: Timestamp

    @TimestampField({ defaultNow: true })
    updatedAt?: Timestamp

    async beforeSave() {
        // Ensure createdAt for new docs
        if (!this.createdAt) this.createdAt = Timestamp.now()
        // Always update updatedAt
        this.updatedAt = Timestamp.now()
    }

    async afterLoad() {
        console.log(`Post ${this.id} loaded at ${new Date().toISOString()}`)
    }
}

Notes

• Error handling: Throwing an error in a before hook will abort the operation.
• Transactions & Batches: Only before hooks run when queuing operations in transactions or batches. after hooks do not run automatically.

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Next: Advanced Usage — explore custom converters, pagination, and Firestore-specific features.