MongoDbPersistence

Abstract persistence component that stores data in MongoDB using the official MongoDB driver.

Implements: IReferenceable, IUnreferenceable, IConfigurable, IOpenable, ICleanable

Description

The MongoDbPersistence class allows you to create persistence components that store data in MongoDBs using the official MongoDB driver.

Important points

This is the most basic persistence component that is only able to store data items of any type. Specific CRUD operations over the data items must be implemented in child classes by accessing the self.__collection property.

Configuration parameters

collection: (optional) MongoDB collection name

connection(s):

discovery_key: (optional) key to retrieve the connection from IDiscovery
host: host name or IP address
port: port number (default: 27017)
uri: resource URI or connection string with all parameters in it

credential(s):

store_key: (optional) key to retrieve the credentials from ICredentialStore
username: (optional) username
password: (optional) user’s password

options:

max_pool_size: (optional) maximum connection pool size (default: 2)
keep_alive: (optional) enable connection keep alive (default: true)
connect_timeout: (optional) connection timeout in milliseconds (default: 5000)
socket_timeout: (optional) socket timeout in milliseconds (default: 360000)
auto_reconnect: (optional) enable auto reconnection (default: true)
reconnect_interval: (optional) reconnection interval in milliseconds (default: 1000)
max_page_size: (optional) maximum page size (default: 100)
replica_set: (optional) name of replica set
ssl: (optional) enable SSL connection (default: false)
auth_source: (optional) authentication source
debug: (optional) enable debug output (default: false).

References

*:logger:*:*:1.0 - (optional) ILogger components to pass log messages
*:discovery:*:*:1.0 - (optional) IDiscovery services
*:credential-store:*:*:1.0 - (optional) credential stores to resolve credentials

Constructors

Creates a new instance of the persistence component.

MongoDbPersistence(collection: str = None)

collection: str - (optional) collection name.

Instance methods

clear

Clears a component’s state.

clear(correlation_id: Optional[str])

correlation_id: Optional[str]- object to convert from the public partial format.

_clear_schema

Clears all auto-created objects

_clear_schema()

close

Closes the component and frees used resources.

close(correlation_id: Optional[str])

correlation_id: Optional[str]- object to convert from the public partial format.

configure

Closes the component and frees used resources.

configure(config: ConfigParams)

config: ConfigParams - configuration parameters to be set.

_convert_from_public

Converts an object value from public to internal format.

_convert_from_public(value: Any): Any

value: Any - object in public format to convert.
returns: Any - converted object in internal format.

_convert_to_public

Converts and object value from internal to public format.

_convert_to_public(value: Any): Any

value: Any - object in internal format to convert.
returns: Any - converted object in public format.

create

Creates a data item.

create(correlation_id: Optional[str], item: T): Optional[T]

correlation_id: Optional[str] - (optional) transaction id used to trace execution through the call chain.
item: T - item to be created.
returns: Optional[T] - created item

_define_schema

Defines the database schema

_define_schema()

delete_by_filter

This method shall be called by a public delete_by_filter method from the child class that receives FilterParams and converts them into a filter function.

delete_by_filter(correlation_id: Optional[str], filter: Any)

correlation_id: Optional[str] - (optional) transaction id used to trace execution through the call chain.
filter: Any - (optional) filter function used to filter items.

_ensure_index

Adds index definition to create it on opening.

_ensure_index(keys: Any, options: Any = None)

keys: Any - index keys (fields)
options: Any - index options

get_count_by_filter

Gets a number of data items retrieved by a given filter.

This method shall be called by a public get_count_by_filter method from the child class that receives FilterParams and converts them into a filter function.

get_count_by_filter(correlation_id: Optional[str], filter: Any): int

correlation_id: Optional[str] - (optional) transaction id usedto trace execution through the call chain.
filter: Any - (optional) filter JSON object
returns: int - number of filtered items.

get_list_by_filter

Gets a list of data items retrieved by a given filter and sorted according to sort parameters.

This method shall be called by a public get_list_by_filter method from the child class that receives FilterParams and converts them into a filter function.

get_list_by_filter(correlation_id: Optional[str], filter: Any, sort: Any = None, select: Any = None): List[T]

correlation_id: Optional[str] - (optional) transaction id used to trace execution through the call chain.
filter: Any - (optional) filter function used to filter items
sort: Any - (optional) sorting parameters
select: Any - (optional) projection parameters (not used yet)
returns: List[dict] - data list of results by filter.

get_one_random

Gets a random item from items that match to a given filter.

This method shall be called by a public get_one_random method from the child class that receives FilterParams and converts them into a filter function.

get_one_random(correlation_id: Optional[str], filter: Any): Optional[T]

correlation_id: Optional[str] - (optional) transaction id used to trace execution through the call chain.
filter: Any - fileter JSON object.
returns: Optional[T] - random item.

get_page_by_filter

Gets a page of data items retrieved by a given filter and sorted according to sort parameters.

This method shall be called by a public get_page_by_filter method from the child class that receives FilterParams and converts them into a filter function.

get_page_by_filter(correlation_id: Optional[str], filter: Any, paging: PagingParams, sort: Any = None, select: Any = None): DataPage

correlation_id: Optional[str] - (optional) transaction id used to trace execution through the call chain.
filter: Any - (optional) filter JSON object
paging: PagingParams - (optional) paging parameters
sort: Any - (optional) sorting JSON object
select: Any - (optional) projection JSON object
returns: DataPage - data page obtained by filtering

Examples

class MyMongoDbPersistence(MongoDbPersistence):
    def __init__(self):
        super(MyMongoDbPersistence, self).__init__("mydata", MyData)

    def get_by_name(self, correlationId, name):
        item =  self._collection.find_one({ 'name': name })
        return item

    def set(self, correlationId, item):
        item = self._collection.find_one_and_update( 
            { '_id': item.id }, { '$set': item }, 
            return_document = pymongo.ReturnDocument.AFTER, 
            upsert = True 
            )

persistence = MyMongoDbPersistence()
persistence.configure(ConfigParams.from_tuples("host", "localhost", "port", 27017))

persitence.open("123")

persistence.set("123", { name: "ABC" })
item = persistence.get_by_name("123", "ABC")

print(item)