spinetoolbox.fetch_parent

The FetchParent and FlexibleFetchParent classes.

Module Contents

Classes

FetchParent	param index: an index to speedup looking up fetched items
ItemTypeFetchParent	param index: an index to speedup looking up fetched items
FlexibleFetchParent	param index: an index to speedup looking up fetched items
FetchIndex	dict() -> new empty dictionary
_ItemCallback

class spinetoolbox.fetch_parent.FetchParent(index=None, owner=None, chunk_size=1000)

Bases: PySide6.QtCore.QObject

Parameters:

• index (FetchIndex, optional) – an index to speedup looking up fetched items

• owner (object, optional) – somebody who owns this FetchParent. If it’s a QObject instance, then this FetchParent becomes obsolete whenever the owner is destroyed

• chunk_size (int, optional) – the number of items this parent should be happy with fetching at a time. If None, then no limit is imposed and the parent should fetch the entire contents of the DB.

property index

abstract property fetch_item_type

Returns the DB item type to fetch, e.g., “entity_class”.

Returns:

str

property is_obsolete

property is_fetched

property is_busy

_changes_pending

apply_changes_immediately()

reset()

Resets fetch parent as if nothing was ever fetched.

position(db_map)

increment_position(db_map)

_apply_pending_changes()

bind_item(item, db_map)

_make_restore_item_callback(db_map)

_make_update_item_callback(db_map)

_make_remove_item_callback(db_map)

_is_valid(version)

_change_item(handler, item, db_map, version)

add_item(item, db_map, version=None)

update_item(item, db_map, version=None)

remove_item(item, db_map, version=None)

key_for_index(db_map)

Returns the key for this parent in the index.

Parameters:

db_map (DatabaseMapping)

Returns:

Any

accepts_item(item, db_map)

Called by the associated SpineDBWorker whenever items are fetched and also added/updated/removed. Returns whether this parent accepts that item as a children.

In case of modifications, the SpineDBWorker will call one or more of handle_items_added(), handle_items_updated(), or handle_items_removed() with all the items that pass this test.

Parameters:

• item (dict) – The item

• db_map (DatabaseMapping)

Returns:

bool

shows_item(item, db_map)

Called by the associated SpineDBWorker whenever items are fetched and accepted. Returns whether this parent will show this item to the user.

Parameters:

• item (dict) – The item

• db_map (DatabaseMapping)

Returns:

bool

set_obsolete(obsolete)

Sets the obsolete status.

Parameters:

obsolete (bool) – whether parent has become obsolete

set_fetched(fetched)

Sets the fetched status.

Parameters:

fetched (bool) – whether parent has been fetched completely

set_busy(busy)

Sets the busy status.

Parameters:

busy (bool) – whether parent is busy fetching

abstract handle_items_added(db_map_data)

Called by SpineDBWorker when items are added to the DB.

Parameters:

db_map_data (dict) – Mapping DatabaseMapping instances to list of dict-items for which accepts_item() returns True.

abstract handle_items_removed(db_map_data)

Called by SpineDBWorker when items are removed from the DB.

Parameters:

db_map_data (dict) – Mapping DatabaseMapping instances to list of dict-items for which accepts_item() returns True.

abstract handle_items_updated(db_map_data)

Called by SpineDBWorker when items are updated in the DB.

Parameters:

db_map_data (dict) – Mapping DatabaseMapping instances to list of dict-items for which accepts_item() returns True.

class spinetoolbox.fetch_parent.ItemTypeFetchParent(fetch_item_type, index=None, owner=None, chunk_size=1000)

Bases: FetchParent

Parameters:

• index (FetchIndex, optional) – an index to speedup looking up fetched items

• owner (object, optional) – somebody who owns this FetchParent. If it’s a QObject instance, then this FetchParent becomes obsolete whenever the owner is destroyed

• chunk_size (int, optional) – the number of items this parent should be happy with fetching at a time. If None, then no limit is imposed and the parent should fetch the entire contents of the DB.

property fetch_item_type

Returns the DB item type to fetch, e.g., “entity_class”.

Returns:

str

abstract handle_items_added(db_map_data)

Called by SpineDBWorker when items are added to the DB.

Parameters:

db_map_data (dict) – Mapping DatabaseMapping instances to list of dict-items for which accepts_item() returns True.

abstract handle_items_removed(db_map_data)

Called by SpineDBWorker when items are removed from the DB.

Parameters:

db_map_data (dict) – Mapping DatabaseMapping instances to list of dict-items for which accepts_item() returns True.

abstract handle_items_updated(db_map_data)

Called by SpineDBWorker when items are updated in the DB.

Parameters:

db_map_data (dict) – Mapping DatabaseMapping instances to list of dict-items for which accepts_item() returns True.

__str__()

class spinetoolbox.fetch_parent.FlexibleFetchParent(fetch_item_type, handle_items_added=None, handle_items_removed=None, handle_items_updated=None, accepts_item=None, shows_item=None, key_for_index=None, index=None, owner=None, chunk_size=1000)

Bases: ItemTypeFetchParent

Parameters:

• index (FetchIndex, optional) – an index to speedup looking up fetched items

• owner (object, optional) – somebody who owns this FetchParent. If it’s a QObject instance, then this FetchParent becomes obsolete whenever the owner is destroyed

• chunk_size (int, optional) – the number of items this parent should be happy with fetching at a time. If None, then no limit is imposed and the parent should fetch the entire contents of the DB.

key_for_index(db_map)

Returns the key for this parent in the index.

Parameters:

db_map (DatabaseMapping)

Returns:

Any

handle_items_added(db_map_data)

Called by SpineDBWorker when items are added to the DB.

Parameters:

db_map_data (dict) – Mapping DatabaseMapping instances to list of dict-items for which accepts_item() returns True.

handle_items_removed(db_map_data)

Called by SpineDBWorker when items are removed from the DB.

Parameters:

db_map_data (dict) – Mapping DatabaseMapping instances to list of dict-items for which accepts_item() returns True.

handle_items_updated(db_map_data)

Called by SpineDBWorker when items are updated in the DB.

Parameters:

db_map_data (dict) – Mapping DatabaseMapping instances to list of dict-items for which accepts_item() returns True.

accepts_item(item, db_map)

Called by the associated SpineDBWorker whenever items are fetched and also added/updated/removed. Returns whether this parent accepts that item as a children.

In case of modifications, the SpineDBWorker will call one or more of handle_items_added(), handle_items_updated(), or handle_items_removed() with all the items that pass this test.

Parameters:

• item (dict) – The item

• db_map (DatabaseMapping)

Returns:

bool

shows_item(item, db_map)

Called by the associated SpineDBWorker whenever items are fetched and accepted. Returns whether this parent will show this item to the user.

Parameters:

• item (dict) – The item

• db_map (DatabaseMapping)

Returns:

bool

class spinetoolbox.fetch_parent.FetchIndex

Bases: dict

dict() -> new empty dictionary dict(mapping) -> new dictionary initialized from a mapping object’s

(key, value) pairs

dict(iterable) -> new dictionary initialized as if via:

d = {} for k, v in iterable:

d[k] = v

dict(**kwargs) -> new dictionary initialized with the name=value pairs

in the keyword argument list. For example: dict(one=1, two=2)

Initialize self. See help(type(self)) for accurate signature.

reset()

abstract process_item(item, db_map)

position(db_map)

increment_position(db_map)

get_items(key, db_map)

class spinetoolbox.fetch_parent._ItemCallback(fn, *args)

__call__(item)

__str__()

Return str(self).