Python HAL generation/parsing library.
Schemas can be defined to specify attributes to be exposed and a structure
import halogen
spell = {
"uid": "abracadabra",
"name": "Abra Cadabra",
"cost": 10,
}
class Spell(halogen.Schema):
self = halogen.Link(URI("spells"), attr="uid")
name = halogen.Attr()
serialized = Spell.serialize(spell)This will produce HAL-like dictionary which can be serialized to json for the hal+json content type or to XML for the hal+xml content type.
{
"_links": {
"self": {"href": "spells/abracadabra"}
},
"name": "Abra Cadabra"
// The extra wasn't in the schema and this way will be ignored
}import halogen
books = [
{
"id": "1",
"name": "Game of Thrones",
},
{
"id": "2",
"name": "Harry Potter",
}
]
class Book(halogen.Schema):
self = halogen.Link(URI("books"), attr="id")
name = halogen.Attr()
class BooksFeed(halogen.Schema):
self = halogen.Link(URI("books"), attr=lambda value: "/")
books = halogen.Embedded(halogen.types.List(Book))
feed = Spell.serialize(books)The serialized data will look like this:
{
"_links": {
"self": {"href": "/books/"}
},
"_embedded": {
"books": [
{
"_links": {
"self": {"href": "/books/1"}
},
"name": "Game of Thrones"
},
{
"_links": {
"self": {"href": "/books/2"}
},
"name": "Harry Potter"
}
]
}
}The HAL data can be deserialized into the output object. In case there are validation errors they will be collected and the ValidationError thrown.
import halogen
hal = {
"_links": {
"self": {"href": "spells/abracadabra"}
},
"name": "Abra Cadabra",
}
class Spell(halogen.Schema):
self = halogen.Link(URI("spells"), attr="uid")
name = halogen.Attr()
spell = {}
Spell.deserialize(hal, output=spell)The deserialized data will look like this:
{
"uid": "abracadabra",
"name": "Abra Cadabra",
}The errors will be related to the attributes.
try:
Spell.deserialize(hal, output=spell)
except halogen.ValidationError as e;
print e.as_dict()