Using Zoom In Client Applications

Cortex uses hypermedia links to associate related resources together. Client applications need to make multiple requests to retrieve information from a resource’s links. Using zoom, you can retrieve all these links with a single request. When a request uses zoom, Cortex retrieves all the requested links and generates a single response containing the linked data. All links that can be retrieved can also be "zoomed".

Example Using zoom

In this example, zoom retrieved the cart resource and its corresponding lineitems and total resources. Once the client application receives the response, JSONPath can extract the data you’re interested in.

{
  "self": {
    "type": "elasticpath.carts.cart",
    "uri": "/carts/mobee/guz=?zoom=lineitems,total",
    "href": "http://api.elasticpath.net/cortex/carts/mobee/guz=?zoom=lineitems,total"
  },
  "total-quantity": 3,
  "links": [
    {
      "rel": "lineitems",
      "rev": "cart",
      "type": "elasticpath.collections.links",
      "uri": "/carts/mobee/guz=/lineitems",
      "href": "http://api.elasticpath.net/cortex/carts/mobee/guz=/lineitems"
    },
    {
      "rel": "order",
      "rev": "cart",
      "type": "elasticpath.orders.order",
      "uri": "/orders/mobee/mu3=",
      "href": "http://api.elasticpath.net/cortex/orders/mobee/mu3="
    },
    {
      "rel": "total",
      "rev": "cart",
      "type": "elasticpath.totals.total",
      "uri": "/totals/carts/mobee/guz=",
      "href": "http://api.elasticpath.net/cortex/totals/carts/mobee/guz="

    }
  ],

  "_lineitems": [
    {
      "self": {
        "type": "elasticpath.collections.links",
        "uri": "/carts/mobee/guz=/lineitems",
        "href": "http://api.elasticpath.net/cortex/carts/mobee/guz=/lineitems"
      },
      "links": [
        {
          "rel": "element",
          "rev": "list",
          "type": "elasticpath.carts.line-item",
          "uri": "/carts/mobee/guz=/lineitems/hfq=",
          "href": "http://api.elasticpath.net/cortex/carts/mobee/guz=/lineitems/hfq="
        },
        {
          "rel": "element",
          "rev": "list",
          "type": "elasticpath.carts.line-item",
          "uri": "/carts/mobee/guz=/lineitems/gbq=",
          "href": "http://api.elasticpath.net/cortex/carts/mobee/guz=/lineitems/gbq="
        },
        {
          "rel": "cart",
          "rev": "lineitems",
          "type": "elasticpath.carts.cart",
          "uri": "/carts/mobee/guz=",
          "href": "http://api.elasticpath.net/cortex/carts/mobee/guz="
        }
      ]
    }
  ],
  "_total": [
    {
      "self": {
        "type": "elasticpath.totals.total",
        "uri": "/totals/carts/mobee/guz=",
        "href": "http://api.elasticpath.net/cortex/totals/carts/mobee/guz="
      },
      "cost": [
        {
          "amount": 211,
          "currency": "CAD",
          "display": "$211.00"
        }
      ],
      "links": [
        {
          "rel": "cart",
          "rev": "total",
          "type": "elasticpath.carts.cart",
          "uri": "/carts/mobee/guz=",
          "href": "http://api.elasticpath.net/cortex/carts/mobee/guz="
        }
      ]
    }
  ]
}

Extract total-quantity child property

JSONPath: $total-quantity

Result:

[
  3
]

Extract every quantity value nested in other properties

JSONPath: $..quantity

Result:

[
  2,
  1
]

Extract first element of total cost array

JSONPath: $_total..cost[0]

Result:

[
  {
    "amount": 211,
    "currency": "CAD",
    "display": "$211.00"
  }
]