Nest

Nest is the nested data primitive behind many Ingest data objects such as app.config, req.data, req.query, req.post, res.data, and res.errors.

This class lives in @stackpress/lib, not in Ingest itself, but Ingest relies on it heavily enough that it is worth understanding.

import { Nest, nest } from '@stackpress/lib';

const config = nest({
  database: {
    postgres: {
      host: 'localhost',
      port: 5432
    }
  }
});

Why it matters in Ingest

Ingest uses the callable form of Nest almost everywhere it needs structured state.

app.config.set('app', { name: 'My App' });

app.get('/users/:id', ({ req, res }) => {
  res.setJSON({
    id: req.data('id'),
    filters: req.query(),
    body: req.post(),
    config: app.config('app', 'name')
  });
});

That is why these data objects behave similarly even though they belong to different classes.

Common operations

The most useful methods are:

config('database', 'postgres', 'host');      // callable read
config.get('database', 'postgres', 'port');  // method read
config.set('database', 'postgres', 'port', 5432);
config.has('database', 'postgres', 'host');
config.path('database.postgres.host');
config.entries();

The callable form is convenient for reads in handlers, while the methods are better when you need more explicit mutation or inspection.

Where you will see it in Ingest

• app.config
• req.query
• req.post
• req.data
• res.data
• res.errors

For example:

app.view.engine = async (filePath, req, res) => {
  const props = res.data();
  const html = await app.view.render(filePath, {
    ...req.data(),
    props
  });
  res.setHTML(html);
};

Parsing helpers

The same module also provides parsing helpers that Ingest adapters use when building request data.

import {
  objectFromQuery,
  objectFromFormData,
  objectFromJson
} from '@stackpress/lib/Nest';

Those helpers are part of how:

• query strings become req.query
• request bodies become req.post
• merged request state becomes req.data

Read next

• Request
• Response
• Server
• Data Surfaces