Chain API call cascade, pass second value as third call argument, "id is not a valid integer"

Question

While making a cascade API call, a roadblock has been hit, here's a code:

$result = civicrm_api3('Contact', 'get', array(
  'sequential' => 1,
  'return' => "id",
  'id' => array('IN' => array(168, 169)),

 // Second call

    'api.Relationship.get' => array(
      'return' => "contact_id_a",
      'contact_id_b' => "\$value.id",
      'relationship_type_id' => 4,
      'is_permission_b_a' => "1"),

          // Third call

        'api.Contact.get' => array('id' => array(
           'IN' => array("\$value.api.relationship.get"))), // <-- here
)); 

It returns

{
    "error_field": "id",
    "type": "integer",
    "error_code": 2001,
    "entity": "Contact",
    "action": "get",
    "is_error": 1,
    "error_message": "Error in call to Contact_get : id is not a valid integer"
}

What exactly returns third call and how these results should be properly "plugged in" to get correct output? Thanks anyone for any bit of advice!

Answer 1

so you are trying to fetch the details of contacts that are related to the ones you search for first? The $value refers to the last call in a nested one.

$result = civicrm_api3('Contact', 'get', array(
  'sequential' => 1,
  'return' => "id",
  'api.Relationship.get' 
   => array(
     'contact_id_a' => "\$value.id",
     'api.contact.get' => "\$value.contact_id_b"),
));

If you want to give more params to the inner api.contact.get:

$result = civicrm_api3('Contact', 'get', array(
  'sequential' => 1,
  'return' => "id",
  'api.Relationship.get' 
   => array('contact_id_a' => "\$value.id", 
     'api.contact.get' 
      => array(
        'id' => "\$value.contact_id_b", 
        'sequential' => 1, 
        'return' => "display_name"
      )
    ),
  )
);