Visibility

TypeScript offers private, protected and public keywords to handle member visibility in a class. However, Dagger will only expose those fields of a Dagger Module that are explicitly decorated with the @field() decorator. Other fields will remain private.

note

Even if a field remains private, its state will still be loaded and it can be used even though it is not exposed via the Dagger API.

Here's an example of a Dagger Module that has multiple properties which are not exposed outside the module, and a Dagger Function that uses the crypto library to hash these:

import * as crypto from "crypto"

import { object, func, field } from "@dagger.io/dagger"

@object()
class person {
  /**
   * Get the name of the person
   */
  @field()
  name: string

  private age: number

  job: string

  constructor(name: string, job: string, age: number) {
    this.name = name
    this.age = age
    this.job = job
  }

  /**
   * Get the identity of the person based on its personal information.
   */
  @func()
  identity(): string {
    return crypto
      .createHash("sha256")
      .update(`${this.name}-${this.job}-${this.age.toString()}`)
      .digest("hex")
  }
}

From dagger functions, it can be seen that age and job are not exposed:

dagger functions
Name       Description
identity   Get the identity of the person based on its personal information.
name       Get the name of the person

Here is an example call for this module:

dagger call --name="john" --age=23 --job="devops" identity

The result will be:

c11fb2dc1c5bfe34b0ed5737b8c58914ddb56a83602ead3eff2f06e46efc4a24