Metadata

If you want to transfer metadata to a service you can use the meta$ property in your pattern. It will be passed in all nested calls. A common use case is to add a JWT token.

Caveats

• Metadata is transfered
• Metadata is pass to all child calls

hemera.add(
  {
    topic: 'math',
    cmd: 'add'
  },
  function(req, cb) {
    //Access to metadata
    let meta = this.meta$

    cb(null, req.a + req.b)
  }
)
hemera.act(
  {
    topic: 'math',
    cmd: 'add',
    a: 1,
    b: 1,
    meta$: { a: 'test' }
  },
  function(err, resp) {
    this.act({
      topic: 'math',
      cmd: 'add',
      a: 1,
      b: 5
    })
  }
)

Attach it outside of the pattern

hemera.meta$.token = 'ABC1234'
hemera.act(
  {
    topic: 'math',
    cmd: 'add',
    a: 1,
    b: 1
  },
  function(err, resp) {
    //or
    this.meta$.token = 'ABC1234'

    this.act({
      topic: 'math',
      cmd: 'add',
      a: 1,
      b: 5
    })
  }
)