Conditional Rendering

Resora includes helper methods for conditional attributes directly on:

• Resource
• ResourceCollection
• GenericResource
• Any resource extended from these base classes.

These helpers keep data() clean and declarative.

Available Helpers

• this.when(condition, value | () => value)
• this.whenNotNull(value)
• this.mergeWhen(condition, object | () => object)

when(condition, value)

Include a value only when the condition is truthy.

class UserResource extends Resource {
  data() {
    return {
      id: this.id,
      role: this.when(this.isAdmin, 'admin'),
    };
  }
}

If isAdmin is false, role is omitted.

Lazy callback form

Use a callback if value computation is expensive.

this.when(this.canViewStats, () => this.buildStats());

The callback runs only when the condition is truthy.

whenNotNull(value)

Include a value only when it is not null and not undefined.

class UserResource extends Resource {
  data() {
    return {
      id: this.id,
      email: this.whenNotNull(this.email),
      avatar: this.whenNotNull(this.avatarUrl),
    };
  }
}

mergeWhen(condition, object)

Conditionally merge a set of attributes into the output object.

class UserResource extends Resource {
  data() {
    return {
      id: this.id,
      ...this.mergeWhen(this.isAdmin, {
        permissions: ['users.read', 'users.write'],
        scope: 'admin',
      }),
    };
  }
}

Lazy callback form

...this.mergeWhen(this.includeExtra, () => ({
  profile: this.buildProfile(),
}))

Complete Example

class UserResource extends Resource {
  data() {
    return {
      id: this.id,
      name: this.name,
      nickname: this.whenNotNull(this.nickname),
      role: this.when(this.isAdmin, 'admin'),
      ...this.mergeWhen(this.isAdmin, {
        permissions: ['manage-users'],
      }),
    };
  }
}

Notes

• Omitted attributes are removed from the final serialized payload.
• These helpers work in collections too, including when using collects on ResourceCollection.
• For metadata customization, see Writing Resources.