ethers.js/docs.wrm/api/providers/provider.wrm

_title: Abstract Provider


_section: Provider @<provider>

Explain what a provider is...


_subsection: Accounts Methods

_property: provider.getBalance(address [ , blockTag = "latest" ]) => Promise<[[bignumber]]>
Returns the balance of //address// as of the //blockTag// block height.

_property: provider.getCode(address [ , blockTag = "latest" ]) => Promise<[[hexstring]]>
Returns the contract code of //address// as of the //blockTag// block height. If there is
no contract currently deployed, the result is ``0x``.

_property: provider.getStorageAt(address, position [ , blockTag = "latest" ]) => Promise<[[hexstring]]>
Returns the ``Bytes32`` value of the //position// at //address//, as of the //blockTag//.

_property: provider.getTransactionCount(address [ , blockTag = "latest" ]) => Promise<number>
Returns the number of transactions //address// has ever **sent**, as of //blockTag//.
This value is required to be the nonce for the next transaction from //address//
sent to the network.

_heading: Examples

_code: example-account.js


_subsection: Blocks Methods

_property: provider.getBlock(block) => Promise<[[provider-block]]>
Get the //block// from the network, where the ``result.transactions`` is a list
of transaction hashes.

_property: provider.getBlockWithTransactions(block) => Promise<[[provider-blocktxs]]>
Get the //block// from the network, where the ``result.transactions`` is
an Array of [[provider-transactionresponse]] objects.


_subsection: Ethereum Naming Service (ENS) Methods

TODO: Explain ENS here...

_property: provider.lookupAddress(address) => Promise<string>
Performs a reverse lookup of the //address// in ENS using the
//Reverse Registrar//.  If the name does not exist, or the
forward lookup does not match, ``null`` is returned.

_property: provider.resovleName(name) => Promise<string>
Looks up the address of //name//. If the name is not owned, or
does not have a //Resolver// configured, or the //Resolver// does
not have an address configured, ``null`` is returned.

_heading: Examples

_code: example-ens.js

_subsection: Logs Methods

_property: provider.getLogs(filter) => Promise<Array<[[provider-log]]>>
Returns the Array of [[provider-log]] matching the //filter//.

Keep in mind that many backends will discard old events, and that requests
which are too broad may get dropped as they require too many resources to
execute the query.


_subsection: Network Status Methods

_property: provider.getNetwork() => Promise<[[provider-network]]>
Returns the [[provider-network]] this Provider is connected to.

_property: provider.getBlockNumber() => Promise<number>
Returns the block number (or height) of the most recently mined block.

_property: provider.getGasPrice() => Promise<[[bignumber]]>
Returns a //best guess// of the [[gas-price]] to use in a transaction.


_subsection: Transactions Methods

_property: provider.call(transaction [ , blockTag = "latest" ]) => Promise<[[hexstring]]>
Returns the result of executing the //transaction//, using //call//. A call 
does not require any ether, but cannot change any state. This is useful
for calling gettings on Contracts.

_property: provider.estimateGas(transaction) => Promise<[[bignumber]]>
Returns an estimate of the amount of gas that would be required to submit //transaction//
to the network.

An estimate may not be accurate since there could be another transaction
on the network that was not accounted for, but after being mined affected
relevant state.

_property: provider.sendTransaction(transaction) => Promise<[[provider-transactionresponse]]>
Submits //transaction// to the network to be mined. The //transaction// **must** be signed,
and be valid (i.e. the nonce is correct and the account has sufficient balance to pay
for the transaction).

_property: provider.waitForTransaction(transactionHash) => Promise<[[provider-transactionreceipt]]>
Returns a Promise which will not resolve until //transactionHash// is mined.


_subsection: Event Emitter Methods

Explain events here...

_property: provider.on(eventName, listener) => this
Add a //listener// to be triggered for each //eventName//.

_property: provider.once(eventName, listener) => this
Add a //listener// to be triggered for only the next //eventName//,
at which time it be removed.

_property: provider.emit(eventName, ...args) => boolean
Notify all listeners of //eventName//, passing //args// to each listener. This
is generally only used internally.

_property: provider.off(eventName [ , listener ]) => this
Remove a //listener// for //eventName//. If no //listener// is provided,
all listeners for //eventName// are removed.

_property: provider.removeAllListeners([ eventName ]) => this
Remove all the listeners for //eventName//. If no //eventName// is provided,
**all** events are removed.

_property: provider.listenerCount([ eventName ]) => number
Returns the number of listeners for //eventName//. If no //eventName// is
provided, the total number of listeners is returned.

_property: provider.listeners(eventName) => Array<Listener>
Returns the list of Listeners for //eventName//.


_subsection: Inspection Methods

_property: Provider.isProvider(object) => boolean
Returns true if and only if //object// is a Provider.