taucmdr.mvc.controller module¶

TODO: FIXME: Docs

class taucmdr.mvc.controller.Controller(model_cls, storage, context=None)[source]¶

Bases: object

The “C” in MVC.

model¶

AbstractModel

Data model.

storage¶

AbstractDatabase

Record storage.

context¶

List(Tuple

A field filter, with syntax (key, value).

Filtering according to a context means that only elements with

at least an element matching the rules set in the context will

be considered. Think of it as a whitelist.

A controller will filters results according to

- By default, nothing;

- If a context was given at the object's initialization,

the controller only allows objects matching the context;

- If a context is given during a command, it overrides the internal

context and the results are matched against it.

_associate(record, foreign_model, affected, via)[source]¶

Associates a record with another record.

Parameters:	record (Record) – Record to associate. foreign_model (Model) – Foreign record’s data model. affected (list) – Identifiers for the records that will be updated to associate with record. via (str) – The name of the associated foreign attribute.

_disassociate(record, foreign_model, affected, via)[source]¶

Disassociates a record from another record.

Parameters:	record (Record) – Record to disassociate. foreign_model (Model) – Foreign record’s data model. affected (list) – Identifiers for the records that will be updated to disassociate from record. via (str) – The name of the associated foreign attribute.

all(*args, **kwargs)[source]¶

count(context=True)[source]¶

Return the number of records.

Returns:	Effectively len(self.all())
Return type:	int

create(data)[source]¶

Atomically store a new record and update associations.

Invokes the on_create callback after the data is recorded. If this callback raises an exception then the operation is reverted.

Parameters:	data (dict) – Data to record.
Returns:	The newly created data.
Return type:	Model

delete(keys, context=True)[source]¶

Delete recorded data and update associations.

The behavior depends on the type of keys:

• Record.ElementIdentifier: delete the record with that element identifier.
• dict: delete all records with attributes matching keys.
• list or tuple: delete all records matching the elements of keys.
• bool(keys) == False: raise ValueError.

Invokes the on_delete callback after the data is deleted. If this callback raises an exception then the operation is reverted.

Parameters:	keys (dict) – Attributes to match. keys – Fields or element identifiers to match.

exists(keys, context=True)[source]¶

Check if a record exists.

Parameters:	keys – See AbstractStorage.exists.
Returns:	True if a record matching keys exists, False otherwise.
Return type:	bool

classmethod export_records(keys=None, eids=None)[source]¶

Export data records.

Constructs a dictionary containing records matching keys or eids and all their associated records. Association fields (model and collection) are not updated and may contain eids of undefined records.

Parameters:	keys (dict) – Attributes to match. eids (list) – Record identifiers to match.
Returns:	Dictionary of tables containing records.
Return type:	dict

Example:

{
 'Brewery': {100: {'address': '4615 Hollins Ferry Rd, Halethorpe, MD 21227',
                   'brews': [10, 12, 14]}},
 'Beer': {10: {'origin': 100, 'color': 'gold', 'ibu': 45},
          12: {'origin': 100, 'color': 'dark', 'ibu': 15},
          14: {'origin': 100, 'color': 'pale', 'ibu': 30}}
}

Beer.export_records(eids=[10])

{
 'Brewery': {100: {'address': '4615 Hollins Ferry Rd, Halethorpe, MD 21227',
                   'brews': [10, 12, 14]}},
 'Beer': {10: {'origin': 100, 'color': 'gold', 'ibu': 45}}
}

static import_records(data)[source]¶

Import data records.

TODO: Docs

match(*args, **kwargs)[source]¶

messages = {}¶

one(*args, **kwargs)[source]¶

classmethod pop_topic(topic)[source]¶

populate(model, attribute=None, defaults=False, context=True)[source]¶

Merges associated data into the model record.

Example

Suppose we have the following Person records:

1: {'name': 'Katie', 'friends': [2, 3]}
2: {'name': 'Ryan', 'friends': [1]}
3: {'name': 'John', 'friends': [1]}

Populating Person({'name': 'Katie', 'friends': [2, 3]}) produces this dictionary:

{'name': 'Katie',
 'friends': [Person({'name': 'Ryan', 'friends': [1]}),
             Person({'name': 'John', 'friends': [1]}]})

Parameters:	attribute (Optional[str]) – If given, return only the populated attribute. defaults (Optional[bool]) – If given, set undefined attributes to their default values.
Returns:	If attribute is None, a dictionary of controlled data merged with associated records. If attribute is not None, the value of the populated attribute.
Raises:	KeyError – attribute is undefined in the record.

classmethod push_to_topic(topic, message)[source]¶

search(*args, **kwargs)[source]¶

unset(fields, keys)[source]¶

Unset recorded data fields and update associations.

The behavior depends on the type of keys:

• Record.ElementIdentifier: update the record with that element identifier.
• dict: update all records with attributes matching keys.
• list or tuple: apply update to all records matching the elements of keys.
• bool(keys) == False: raise ValueError.

Invokes the on_update callback after the data is modified. If this callback raises an exception then the operation is reverted.

Parameters:	fields (list) – Names of fields to unset. keys – Fields or element identifiers to match.

update(data, keys)[source]¶

Change recorded data and update associations.

The behavior depends on the type of keys:

• Record.ElementIdentifier: update the record with that element identifier.
• dict: update all records with attributes matching keys.
• list or tuple: apply update to all records matching the elements of keys.
• bool(keys) == False: raise ValueError.

Invokes the on_update callback after the data is modified. If this callback raises an exception then the operation is reverted.

Parameters:	data (dict) – New data for existing records. keys – Fields or element identifiers to match.

taucmdr.mvc.controller.contextualize(function)[source]¶

taucmdr.mvc.controller.valid(context, record)[source]¶