References

Template references#

Resources could contain references to other resources. These references are defined inside templates. A template inside a property is initialized with two curly brackets {{ }}.

All references consist out of two parts. The resource you want to reference, and the property path {{ <resource>:<path> }}. Paths reference a property within the resource. Paths could target single properties or entire objects.

Resource properties#

A template reference consist out of the following parts: <resource>:<path>. Some resources consist out of multiple resource properties. The default resource property is used when no resource property is given. The following resource properties are available for the variouse resources:

Input
Error
Resource

Parameter	Template	Note
request	`{{ input.request:path }}`	default
header	`{{ input.header:path }}`

Parameter	Template	Note
response	`{{ error.response:path }}`	default
params	`{{ error.params:path }}`

Parameter	Template	Note
request	`{{ resource.request:path }}`
response	`{{ resource.response:path }}`	default
header	`{{ resource.header:path }}`
error	`{{ resource.error:path }}`	only self references

Properties in action#

flow "FetchUser" {
  input "com.org.User" {
    header = ["Authorization"]
  }

  error "com.org.Unexpected" {
    trace = "{{ error.params:trace }}"
    message = "{{ error:message }}"
  }

  resource "user" {
    request "com.org.Users" "Single" {
      id = "{{ input:id }}" // using the default parameter
    }

    on_error {
      schema = "com.org.Unexpected"
      message = "{{ user.error:message }}"
      status = 500

      params {
        trace = "{{ user.error:trace }}"
      }
    }
  }

  output "com.org.User" {
    full_name = "{{ user:bio.full_name }}"
  }
}

Resource dependencies#

References automatically define dependencies across resources. Sometimes do resources depend on one another without a direct reference. Dependencies could manually be created through the depends_on property.

resource "warehouse" {
  request "com.org.Wharehouse" "Ship" {
    product = "{{ input:product }}"
  }
}

resource "log" {
  depends_on = ["warehouse"]

  request "com.org.Logger" "Append" {
    message = "{{ input:message }}"
  }
}