hypercat.py 0.1.0b2

Use cases

Servers:

• Create an empty Hypercat catalogue

• Optionally, add metadata to describe it

• Optionally, add items to the catalogue

  • an item is either another catalogue or a resource

• Output it as JSON, either minimally or prettyprinted

• Find a specific part of a catalogue hierarchy

Clients:

• Load and validate a Hypercat

Example - Hypercat server

We’ll create a Hypercat catalogue with 2 items in it:

  h
 / \
h2  r

Usage:

from hypercat import hypercat

# Create a catalogue
h = hypercat.hypercat("CatalogueContainingOneCatalogueAndOneResource")

# Create a second catalogue, and add it as a child of the first
h2 = hypercat.hypercat("ChildCatalogue")
h.addItem(h2, "/child_cat")

# Create a resource, and add it as another child of the first catalogue
r = hypercat.resource("resource1", "application/vnd.hypercat.sensordata+json")
h.addItem(r, "/resource")

# Print the raw JSON of the catalogue, and then with human-friendly formatting
print h.asJSON()
print h.prettyprint()

This should output:

{
    "catalogue-metadata": [
        {
            "rel": "urn:X-hypercat:rels:isContentType",
            "val": "application/vnd.hypercat.catalogue+json"
        },
        {
            "rel": "urn:X-hypercat:rels:hasDescription:en",
            "val": "CatalogueContainingOneCatalogueAndOneResource"
        }
    ],
    "items": [
        {
            "href": "/child_cat",
            "item-metadata": [
                {
                    "rel": "urn:X-hypercat:rels:isContentType",
                    "val": "application/vnd.hypercat.catalogue+json"
                },
                {
                    "rel": "urn:X-hypercat:rels:hasDescription:en",
                    "val": "ChildCatalogue"
                }
            ]
        },
        {
            "href": "/resource",
            "item-metadata": [
                {
                    "rel": "urn:X-hypercat:rels:isContentType",
                    "val": "application/vnd.hypercat.sensordata+json"
                },
                {
                    "rel": "urn:X-hypercat:rels:hasDescription:en",
                    "val": "resource1"
                }
            ]
        }
    ]
}

Example - Hypercat Client

Usage:

from hypercat import hypercat

h = hypercat.loads(inString)  # Read-in and validate Hypercat
print "Metadata is ",h.metadata