.. _web3-core-subscriptions: .. include:: include_announcement.rst ========================= Core Subscriptions Module ========================= The ``Core Subscriptions Module`` does provide all the subscriptions classes to extend and execute them. .. _web3-module-abstract-subscription: AbstractSubscription ==================== Source: `AbstractSubscription `_ The ``AbstractSubscription`` class extends from the ``EventEmitter`` object and does have the following constructor parameters: - :ref:`type ` - ``String`` The subscriptions type ``eth_subscribe`` or ``shh_subscribe``. - :ref:`method ` - ``String`` The subscription method which is the first parameter in the JSON-RPC payload object. - :ref:`options ` - ``Object`` The options object of the subscription. - :ref:`formatters ` - ``Object`` The formatters object. - :ref:`moduleInstance ` - ``AbstractWeb3Module`` An ``AbstractWeb3Module`` instance. The ``AbstractSubscription`` class is the base subscription class of all subscriptions. You're able to overwrite these methods: - :ref:`subscribe ` - :ref:`unsubscribe ` - :ref:`beforeSubscription ` - :ref:`onNewSubscriptionItem ` .. _web3-module-abstract-subscription-subscribe: subscribe ========= .. code-block:: javascript subscription.subscribe(callback) This method will start the subscription. ---------- Parameters ---------- - ``callback`` - ``Function`` ------- Returns ------- ``AbstractSubscription`` ------------------------------------------------------------------------------------------------------------------------ .. _web3-module-abstract-subscription-unsubscribe: unsubscribe =========== .. code-block:: javascript subscription.unsubscribe(callback) This method will end the subscription. ---------- Parameters ---------- - ``callback`` - ``Function`` ------- Returns ------- ``Promise`` ------------------------------------------------------------------------------------------------------------------------ .. _web3-module-abstract-subscription-before-subscription: beforeSubscription ================== .. code-block:: javascript subscription.beforeSubscription(moduleInstance) This method will be executed before the subscription happens. The ``beforeSubscription`` method gives you the possibility to customize the subscription class before the request will be sent. ---------- Parameters ---------- - ``moduleInstance`` - ``AbstractWeb3Module`` The current ``AbstractWeb3Module``. ------------------------------------------------------------------------------------------------------------------------ .. _web3-module-abstract-subscription-on-new-subscription-item: onNewSubscriptionItem ===================== .. code-block:: javascript subscription.onNewSubscriptionItem(moduleInstance) This method will be executed on each subscription item. The ``onNewSubscriptionItem`` method gives you the possibility to map the response. ---------- Parameters ---------- - ``item`` - ``any`` ------- Returns ------- ``any`` ------------------------------------------------------------------------------------------------------------------------ .. _web3-module-abstract-subscription-type: type ==== .. code-block:: javascript subscription.type The property ``type`` does contain the subscription type. ------- Returns ------- ``String`` - ``eth_subscribe`` or ``shh_subscribe`` ------------------------------------------------------------------------------------------------------------------------ .. _web3-module-abstract-subscription-method: method ====== .. code-block:: javascript subscription.method The property ``method`` does contain the subscription method. ------- Returns ------- ``String`` ------------------------------------------------------------------------------------------------------------------------ .. _web3-module-abstract-subscription-options: options ======= .. code-block:: javascript subscription.options The property ``options`` does contain the subscription options. ------- Returns ------- ``Object`` ------------------------------------------------------------------------------------------------------------------------ .. _web3-module-abstract-subscription-id: id ==== .. code-block:: javascript subscription.id The property ``id`` does contain the subscription id when the subscription is running. ------- Returns ------- ``String`` ------------------------------------------------------------------------------------------------------------------------