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provenance.models module

This module provides models required for the creation, storage and manipulation of PROV documents.

These PROV documents describe actions made by users and applications, allowing usage patterns to be tracked.

For details on PROV see https://www.w3.org/TR/2013/NOTE-prov-overview-20130430/

class provenance.models.ProvAbleModel

Bases: object

Mixin for models which are capable of having updates tracked by PROV records.

Creates a new PROV record every time the object is modified and saved.

save(*args, **kwargs)

class provenance.models.ProvActivity

Bases: enum.Enum

Enum representing the types of activity to be tracked by PROV.

ACCESS = 'piot:access'

UPDATE = 'piot:update'

class provenance.models.ProvApplicationModel(*args, **kwargs)

Bases: object

Dummy application model to fall back to when an action was performed via the PEDASI web interface.

Also to be used as parent class of Application to help with type hinting.

get_absolute_url()

Return the URL at which PEDASI is hosted.

class provenance.models.ProvEntry(*args, **values)

Bases: mongoengine.document.DynamicDocument

Stored PROV record for a single action.

e.g. Update a model’s metadata, use a model.

These will be referred to by a ProvWrapper document.

exception DoesNotExist

Bases: mongoengine.errors.DoesNotExist

exception MultipleObjectsReturned

Bases: mongoengine.errors.MultipleObjectsReturned

classmethod create_prov(instance: core.models.BaseAppDataModel, user_uri: str, application: Union[provenance.models.ProvApplicationModel, NoneType] = None, activity_type: Union[provenance.models.ProvActivity, NoneType] = <ProvActivity.UPDATE: 'piot:update'>) → provenance.models.ProvEntry

Build a PROV document representing a particular activity within PEDASI.

Parameters:

• instance – Application or DataSource which is the object of the activity
• user_uri – URI of user who performed the activity
• application – Application which the user used to perform the activity
• activity_type – Type of the activity - from ProvActivity

Returns:

PROV document in PROV-JSON form

classmethod deserialize(source=None, content: str = None, format: str = 'json', **kwargs)

Create an instance of ProvEntry from another instance or a string document.

Used to create a ProvEntry from a serialized PROV document.

Provide one of ‘source’ or ‘content’.

Parameters:

• source – Source from which to copy object
• content – Text from which to create object
• format – Format of text - e.g. JSON

Returns:

New instance of ProvEntry

id

A field wrapper around MongoDB’s ObjectIds.

objects

class provenance.models.ProvWrapper(*args, **values)

Bases: mongoengine.document.Document

Wrapper around a single PROV record (ProvEntry) which allows it to be easily linked to an instance of a Django model.

This is managed using MongoEngine rather than as a Django model.

exception DoesNotExist

Bases: mongoengine.errors.DoesNotExist

exception MultipleObjectsReturned

Bases: mongoengine.errors.MultipleObjectsReturned

app_label

App from which the model comes

classmethod create_prov(instance: core.models.BaseAppDataModel, user_uri: str, application: Union[provenance.models.ProvApplicationModel, NoneType] = None, activity_type: Union[provenance.models.ProvActivity, NoneType] = <ProvActivity.UPDATE: 'piot:update'>) → provenance.models.ProvEntry

Create a PROV record for a single action.

e.g. Update a model’s metadata, use a model.

These will create and return a ProvEntry document.

delete(signal_kwargs=None, **write_concern)

Delete this document and the ProvEntry to which it refers.

entry

The actual PROV entry

classmethod filter_model_instance(instance: core.models.BaseAppDataModel) → django.db.models.query.QuerySet

Get all ProvEntry documents related to a particular Django model instance.

Parameters:instance – Model instance for which to get all ProvEntrys Returns:List of ProvEntrys

id

A field wrapper around MongoDB’s ObjectIds.

instance

Return the Django model instance to which this ProvWrapper refers.

model_name

Name of the model

objects

related_pk

Primary key of the model instance