Collection+JSON items that link to other collection's items

Question

I am doing a REST web server in nodejs and I was thinking to implement it using Collection+JSON as hypermedia-type.

However I did not understand if it is possible to represent in the collection 1 to n relationships. So if for example I have a collection Basket it is possible to make the items inside Basket to point to item of other defined collection?

Answer 1

Using the traditional ecommerce example, here's how a collection-JSON endpoint for a product might be structured. Note that your client should group by rel-tag. Your rel tag list is your "contract" with your clients. "This rel tag always means that."

"collection":
{
  "href": "/products/1234.json",
  "items":
  [
    {
      "name": "name",
      "value": "10 Speed Bike"
    }
    {
      "name": "manufacturer",
      "value": "Schwin"
    }
    {
      "name": "price",
      "value": 150.00
    }
  ],
  "links":
  [
    {
      "href": "/products/1234/attachments/flier.pdf",
      "rel": "attachment",
      "prompt": "Flier from the Manufacturer",
      "render": "link"
    },
    {
      "href": "/products/1234/attachments/specs.pdf",
      "rel": "attachment",
      "prompt": "Spec Sheet from Manufacturer",
      "render": "link"
    },
    {
      "href": "/products/1234/attachments/warranty.pdf",
      "rel": "attachment",
      "prompt": "Limited Lifetime Warranty",
      "render": "link"
    },
    {
      "href": "/store/attachments/returns.pdf",
      "rel": "attachment",
      "prompt": "Our Return Policy",
      "render": "link"
    },
    {
      "href": "/images/1235478324.png",
      "rel": "product-image",
      "prompt": "A Schwin 10-speed bike in red",
      "render": "image"
    },
    {
      "href": "/images/1235478355.png",
      "rel": "product-image",
      "prompt": "A girl riding a 10-speed bike.",
      "render": "image"
    },
    {
      "href": "/images/1235478385.png",
      "rel": "product-image",
      "prompt": "A grandma watching grandkids ride bicycles.",
      "render": "image"
    },
    {
      "href": "/images/1235478545.png",
      "rel": "swatch",
      "prompt": "Radiant Red",
      "render": "image"
    },
    {
      "href": "/images/1235478545.png",
      "rel": "swatch",
      "prompt": "Brilliant Blue",
      "render": "image"
    },
    {
      "href": "/images/1235478588.png",
      "rel": "swatch",
      "prompt": "Stunning Silver",
      "render": "image"
    },
    {
      "href": "/blog/2014/07/26",
      "rel": "content",
      "prompt": "Our store now sells Schwin bicycles!",
      "render": "link"
    },
    {
      "href": "/manufacturers/schwin",
      "rel": "manufacturer",
      "prompt": "Schwin",
      "render": "link"
    },      ]
}

In this example, the client would know that the presence of a "swatch" rel-tag means that it should show the color swatches section... one swatch for every "rel-tag." Your client might even render differently if there is 1 swatch vs many.

You could be forgiven for wanting to extend collection+JSON ( I've extended it extensively ). collection+JSON's verbose syntax, which I initially saw as a problem, in fact provides a great way to extend while maintaining backwards-compatibility.

Answer 2

You can use the collection link relation, which is described as:

Refers to a resource which represents a collection of which the current resource is a member.

This seems to meet your need.