maxon.AssetRepositoryInterface¶

Description¶

An AssetRepositoryInterface manages a set of assets: - Assets can be looked up using their identifier and version. - New assets or new asset versions can be stored. - Each asset can have associated meta data which can be read and written. - Observers for changes to the repository can be added.

An asset repository can have several base repositories which are used for the lookup after lookup in the repository itself has finished. Cycles aren’t allowed, so asset repositories form a directed acyclic graph.

A repository which has another repository as (direct or indirect) base is said to be derived from that repository. Whenever an observable of a repository is triggered, this is done for all derived repositories too.

The methods of maxon.AssetRepositoryInterface are thread-safe. This allows for concurrent modifications and queries.

Inheritance diagram¶

Inheritance

Parent Class:

Children Classes:

Methods Signature¶

`AddBase`(base)	Adds base to the list of base repositories of this repository.
`CompareVersions`(first, second)	Compares the versions of assets of this repository:
`CopyAsset`(aid, source[, addEncryption, …])	Copies an asset including meta data to this repository using the identifier aid for the copy.
`DeleteAsset`(aid)	Deletes the asset given by the identifier aid.
`EraseAsset`(asset)	Permanently erases an asset version.
`FindAssets`(assetType[, aid, version, …])	Finds all assets matching the parameters:
`FindLatestAsset`(type, aid, version, findMode)	Finds the asset with the given identifier in this repository and its base repositories.
`FindRepository`(repoId)	Finds the repository with the given identifier among this repository and its direct and indirect bases.
`GetBases`()	Returns an array holding all current base repositories of this repository.
`GetDerived`([receiver])	Yields all derived repositories of this repository to #receiver (those which have this repository as direct base).
`GetDescription`(asset)	returns the AssetDescription of the given asset.
`GetDescriptionDatabaseId`()	return
`GetId`()	Returns the identifier of this repository.
`GetRepositoryName`(language)	Returns the name of the repository in the requested language.
`HandleDownloadStateChanged`(repository, finished)	Informs all observers of ObservableDownloadStateChanged and calls HandleDownloadStateChanged on all derived repositories.
`InitBases`(bases)	Initializes the base repositories of this repository.
`IsBasedOnOrSame`(other)	Returns True if this repository is based on other or other itself, False otherwise.
`IsWritable`()	Tells if this repository is writable or not.
`LoadDescriptionAssetId`(category, language, …)
`LoadDescriptionDefinition`(mode, category, …)	param mode
`OverwriteAsset`(aid, asset[, metaData])	Stores asset as a new version using the identifier aid.
`RemoveBase`(base)	Removes base from the list of base repositories of this repository.
`SetRepositoryName`(name, language)	Sets the name of the repository in the given language.
`StoreAsset`(aid, asset[, metaData])	Stores asset as a new version using the identifier aid.
`StoreMetaData`(asset, metaId, data, kind)	Stores data for the meta data attribute metaId of the given asset.
`StoreUrlMetaData`(asset, metaId, data, kind)	Stores data for the meta data attribute metaId of the given asset.

Methods Definition¶

AssetRepositoryInterface.AddBase(base)¶

Adds base to the list of base repositories of this repository. The observers for ObservableBaseChanged of this repository and its derived repositories are informed.

Parameters: base (maxon.AssetRepositoryRef) – The base repository to add.

AssetRepositoryInterface.CompareVersions(first, second)¶

Compares the versions of assets of this repository:

If #first is newer, returns maxon.COMPARERESULT.GREATER.
If #second is newer, returns maxon.COMPARERESULT.LESS.
If both denote the same asset version, returns maxon.COMPARERESULT.EQUAL.

Being newer isn’t based on the time stamp, but on the order in which assets are stored. It also takes into account the update counter (AssetBaseWithUpdateInterface.GetUpdate()) when both assets have the same version identifier.

If both assets have different asset identifiers the method returns maxon.COMPARERESULT.INCOMPARABLE. If the assets don’t belong to this repository, the result is unspecified.

Parameters

first (maxon.AssetBase) – The first asset.
second (maxon.AssetBase) – The second asset.

Returns

The result of the comparison of the versions.

Return type

maxon.COMPARERESULT

AssetRepositoryInterface.CopyAsset(aid, source, addEncryption=False, overwrite=False)¶

Copies an asset including meta data to this repository using the identifier aid for the copy.

source has to be an asset already stored in some repository.

The version identifier of source will be used for the copy even if this repository would normally derive a different identifier from the asset content.

Note

Observers of ObservableAssetStored of this repository and its derived repositories are informed.

Parameters

aid (maxon.Id) – The asset identifier to use.
source (maxon.AssetDescription) – The source asset to copy.
addEncryption (bool) – True if the copy shall be stored in an encrypted way. The encryption has to be handled by the maxon.AssetType.
overwrite (bool) – True to overwrite the existing asset.

Returns

The maxon.AssetDescription of the copy.

Return type

maxon.AssetDescription

AssetRepositoryInterface.DeleteAsset(aid)¶

Deletes the asset given by the identifier aid.

The previous versions still exist in the repository, this method just stores a delete marker so that AssetRepositoryInterface.FindAssets() doesn’t take those versions into account unless the ASSET_FIND_MODE.WITH_DELETED flag is given.

For a complete removal of a specific version use AssetRepositoryInterface.EraseAsset.().

Note

Observers of ObservableAssetStored of this repository and its derived repositories are informed.

Parameters: aid (maxon.aid) – The asset to delete.
Returns: The maxon.AssetDescription which represents the delete marker.
Return type: maxon.AssetDescription

AssetRepositoryInterface.EraseAsset(asset)¶

Permanently erases an asset version.

Unlike AssetRepositoryInterface.DeleteAsset() which marks an asset as deleted but keeps all previous versions this method completely removes any data of the given asset version.

Note

Observers of ObservableAssetErased of this repository and its derived repositories are informed.

Parameters: asset (maxon.AssetDescription) – The asset version to erase from this repository.

AssetRepositoryInterface.FindAssets(assetType, aid=None, version=None, findMode=1, receiver=None)¶

Finds all assets matching the parameters:

If aid is set, only assets with that identifier are found (or which have the aid as prefix when maxon.ASSET_FIND_MODE.PREFIX is set), otherwise all assets.
If version is set, only assets with that version are found, otherwise
if maxon.ASSET_FIND_MODE.LATEST is set in findMode, only the latest asset version is found
if maxon.ASSET_FIND_MODE.ALL is set in findMode, all asset versions are found.
If maxon.ASSET_FIND_MODE.WITHOUT_BASES is set in findMode, then base repositories aren’t taken into account. Otherwise, they are considered after this repository.
If maxon.ASSET_FIND_MODE.WITH_DELETED is set in findMode, then also deleted assets are reported.

When version is given or maxon.ASSET_FIND_MODE.LATEST is used and a matching asset is found in a repository, assets in base repositories thereof aren’t reported even if they are newer. So then an asset in a repository hides assets with the same identifier in base repositories. Assets with another identifier are still reported.

Parameters

assetType (Union[Collection[maxon.Id], maxon.Id, maxon.AssetType, maxon.BaseArray [maxon.Id]]) – The allowed asset type.
aid (maxon.Id) – The asset identifier to lookup, use an empty identifier to find all assets.
version (maxon.Id) – The version identifier to find, use an empty identifier to find all versions.
findMode (maxon.ASSET_FIND_MODE) – Flags for the lookup.
receiver (Union[None, list, Callable[[maxon.AssetDescription], bool]]) – All found assets are reported to this receiver.

Returns

If callback is None or a list then a list of maxon.AssetDescription otherwise False if callback cancelled further evaluation, True otherwise.

Return type

Union[list[maxon.AssetDescription], bool]

AssetRepositoryInterface.FindLatestAsset(type, aid, version, findMode)¶

Finds the asset with the given identifier in this repository and its base repositories. If version is set, this finds the asset with that version, otherwise it finds the latest asset. When a matching asset is found in a repository, assets in base repositories thereof aren’t considered even if they are newer

Parameters

type (Union[maxon.Id, maxon.AssetType, maxon.BaseArray [maxon.Id]) – The allowed asset type.
aid (maxon.Id) – The asset identifier to lookup, use an empty identifier to find all assets.
version (maxon.Id) – The version identifier to find, use an empty identifier to find all versions.
findMode (maxon.ASSET_FIND_MODE) – Flags for the lookup.

Returns

The found asset, or a null reference.

Return type

maxon.AssetDescription

AssetRepositoryInterface.FindRepository(repoId)¶

Finds the repository with the given identifier among this repository and its direct and indirect bases. If no such repository exists, a null reference is returned, use Data.IsNullValue() to test it.

Parameters: repoId (maxon.Id) – The identifier of the repository to find.
Returns: The found repository, or a null reference.
Return type: maxon.AssetRepositoryRef

AssetRepositoryInterface.GetBases()¶

Returns an array holding all current base repositories of this repository.

Note

A repository must not have the same identifier as one of its (direct or indirect) bases.

Returns: The identifier of this repository.
Return type: maxon.BaseArray`[:class:`maxon.AssetRepositoryRef]

AssetRepositoryInterface.GetDerived(receiver=None)¶

Yields all derived repositories of this repository to #receiver (those which have this repository as direct base).

Parameters: receiver (Union[None, list, Callable[[maxon.AssetRepositoryRef], bool]]) – The receiver for derived repositories., return False to cancel further evaluation.
Returns: If receiver is None or a list then a list of maxon.AssetRepositoryRef otherwise False if callback cancelled further evaluation, True otherwise.
Return type: Union[list[maxon.AssetRepositoryRef], bool]

AssetRepositoryInterface.GetDescription(asset)¶

returns the AssetDescription of the given asset.

Parameters: asset (maxon.Asset) – Asset to query.
Returns: AssetDescription on success.
Return type: maxon.AssetDescription

AssetRepositoryInterface.GetDescriptionDatabaseId()¶

Returns
Return type: maxon.Id

AssetRepositoryInterface.GetId()¶

Returns the identifier of this repository. Repository identifiers needn’t be unique, but a repository must not have the same identifier as one of its (direct or indirect) bases.

Returns: The identifier of this repository.
Return type: maxon.Id

AssetRepositoryInterface.GetRepositoryName(language)¶

Returns the name of the repository in the requested language.

Parameters: language (maxon.LanguageRef) – Language to query.
Returns: Name on success.
Return type: str

AssetRepositoryInterface.HandleDownloadStateChanged(repository, finished)¶

Informs all observers of ObservableDownloadStateChanged and calls HandleDownloadStateChanged on all derived repositories.

Parameters

repository (maxon.AssetRepositoryRef) – The repository.
finished (bool) – True if finished.

AssetRepositoryInterface.InitBases(bases)¶

Initializes the base repositories of this repository. This function may only be called once right after the maxon.AssetRepositoryInterface instance has been created.

Note

It doesn’t inform any observers.

Parameters: bases (maxon.Block [maxon.AssetRepositoryRef]) – The bases of this repository.

AssetRepositoryInterface.IsBasedOnOrSame(other)¶

Returns True if this repository is based on other or other itself, False otherwise.

Parameters: other (Union[maxon.AssetRepositoryRef, str, maxon.Id, maxon.String]) – A repository or a repository identifier.
Returns: True if other is a direct or indirect base of this repository or this repository itself.
Return type: bool

AssetRepositoryInterface.IsWritable()¶

Tells if this repository is writable or not.

Returns: True if this repository is writable, False otherwise.
Return type: bool

AssetRepositoryInterface.LoadDescriptionAssetId(category, language, dataType)¶

AssetRepositoryInterface.LoadDescriptionDefinition(mode, category, language, asset)¶

Parameters

mode (maxon.LOADDESCRIPTIONMODE) –
category (maxon.Id) –
language (maxon.LanguageRef) –
asset (maxon.AssetDescription) –

Returns

Return type

DataDescriptionDefinition

AssetRepositoryInterface.OverwriteAsset(aid, asset, metaData=None)¶

Stores asset as a new version using the identifier aid.

Identifier, version and repository are set correspondingly at #asset, so asset may point to a copy of the original object afterwards (Asset is a copy-on-write reference).

Note

Observers of ObservableAssetStored of this repository and its derived repositories are informed.

Parameters

aid (maxon.Id) – The asset identifier to use.
asset (maxon.Asset) – The asset object to store. This method sets identifier, version and repository of asset.
metaData (Optional[maxon.AssetMetaData]) – Initial meta data to use for the asset.

Returns

The maxon.AssetDescription for the added asset.

Return type

maxon.AssetDescription

AssetRepositoryInterface.RemoveBase(base)¶

Removes base from the list of base repositories of this repository. The observers for ObservableBaseChanged of this repository and its derived repositories are informed. Nothing happens if this repository doesn’t have #base as one of its bases.

Parameters: base (maxon.AssetRepositoryRef) – The base repository to remove.

AssetRepositoryInterface.SetRepositoryName(name, language)¶

Sets the name of the repository in the given language.

Parameters

name (str) – Name to set.
language (maxon.LanguageRef) – Language

AssetRepositoryInterface.StoreAsset(aid, asset, metaData=None)¶

Stores asset as a new version using the identifier aid.

Identifier, version and repository are set correspondingly at #asset, so asset may point to a copy of the original object afterwards (Asset is a copy-on-write reference).

Note

Observers of ObservableAssetStored of this repository and its derived repositories are informed.

Parameters

aid (maxon.Id) – The asset identifier to use.
asset (maxon.Asset) – The asset object to store. This method sets identifier, version and repository of asset.
metaData (Optional[maxon.AssetMetaData]) – Initial meta data to use for the asset.

Returns

The maxon.AssetDescription for the added asset.

Return type

maxon.AssetDescription

AssetRepositoryInterface.StoreMetaData(asset, metaId, data, kind)¶

Stores data for the meta data attribute metaId of the given asset.

Note

Observers of ObservableMetaDataStored of this repository and its derived repositories are informed.

Parameters

asset (maxon.AssetDescription) – The asset for which a meta data value shall be set.
metaId (maxon.InternedId) – The identifier of the meta data attribute.
data (maxon.Data) – The value to set.
kind (maxon.AssetMetaDataInterface.KIND) – The kind of the meta data.

AssetRepositoryInterface.StoreUrlMetaData(asset, metaId, data, kind)¶

Stores data for the meta data attribute metaId of the given asset.

Note

Observers of ObservableMetaDataStored of this repository and its derived repositories are informed.

Parameters

asset (maxon.AssetDescription) – The asset for which a meta data value shall be set.
metaId (maxon.InternedId) – The identifier of the meta data attribute.
data (maxon.Data) – The value to set.
kind (maxon.AssetMetaDataInterface.KIND) – The kind of the meta data.