Reading and writing resources

Writing and reading resources on the user’s Pod is easy thanks to the LDP specification and to the proxy endpoint.

Reading and writing resources

If you need to read or write data to the Pod, you can use the PodResourcesService.

const resourceUri = await ctx.call('pod-resources.post`, {
  containerUri: 'http://localhost:3000/alice/data/as/event',
  resource: {
    type: 'Event',
    name: 'Birthday party',
  }',
  actorUri: 'http://localhost:3000/alice'
});

const { body: resource } = await ctx.call('pod-resources.get`, {
  resourceUri,
  actorUri: 'http://localhost:3000/alice'
});

See the PodResourcesService reference for all available actions.

Remote resources

If the resources you want to fetch is not in the Pod of the user (actorUri) but on another Pod, the service will automatically pass through the proxy endpoint of the user. However the proxy endpoint will only allow you to read or write data that you requested during the registration.

Creating a dedicated service

Since your application is likely to deal mainly with certain types of resources, you can use the PodResourcesHandlerMixin to interact with the Pod more easily. This mixin contains the same type of actions as the PodResourcesMixin, except that you don’t need to provide the containerUri for the post and list actions: it will be automatically guessed based on the type setting of the mixin.

const { PodResourcesHandlerMixin } = require('@activitypods/app');

module.exports = {
  name: 'events',
  mixins: [PodResourcesHandlerMixin],
  settings: {
    type: 'as:Event'
  }

Listening to resources changes

The PodResourcesHandlerMixin can also be used to listen for changes in the Pod. If you set the onCreate, onUpdate, or onDelete methods, the mixin will automatically watch for Create, Update, and Delete activities related to these resources, thanks to the PodActivitiesWatcherService.

const { triple, namedNode, literal } = require('@rdfjs/data-model');
const { PodResourcesHandlerMixin } = require('@activitypods/app');

module.exports = {
  name: 'events',
  mixins: [PodResourcesHandlerMixin],
  settings: {
    type: 'as:Event'
  },
  methods: {
    async onCreate(ctx, resource, actorUri) {
      await this.actions.patch(
        {
          resourceUri: resource.id || resource['@id'],
          triplesToAdd: [
            triple(
              namedNode(resource.id || resource['@id']),
              namedNode('https://www.w3.org/ns/activitystreams#summary'),
              literal('An incredible AI-generated summary')
            )
          ],
          actorUri
        },
        { parentCtx: ctx }
      );
    },
    async onUpdate(ctx, resource, actorUri) {
      // Handle post-update actions
    },
    async onDelete(ctx, resource, actorUri) {
      // Handle post-delete actions
    }
  }
};