Arbitrum API method used to remove a filter previously created using one of the following methods:
Upon successful execution, the filter is removed and will no longer emit events.
This method can be useful for optimizing resource usage when a developer no longer needs to monitor certain events or blocks. It can also be used to clean up unused filters in order to reduce clutter in the client-side filter list.
Disclaimer
Note that the default interactive example in this page will not work as the filter will be expired.
To test
eth_uninstallFilter
in this page, first create a new filter using one of the following:Then use the fresh filter ID as the parameter for
eth_uninstallFilter
.
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Parameters
string
β the filter ID that you want to uninstall
Response
boolean
β a boolean value indicating whether the filter was successfully uninstalled.true
if successfully removed, andfalse
if not.
eth_uninstallFilter
code examples
eth_uninstallFilter
code examplesNote that the
web3.eth.filter
methods have been deprecated and replaced with theweb3.eth.subscribe
in web3.js. See web3.js subscriptions.
const ethers = require('ethers');
const NODE_URL = "CHAINSTACK_NODE_URL";
const provider = new ethers.JsonRpcProvider(NODE_URL);
async function removeFilter(filter) {
try {
const removed = await provider.send('eth_uninstallFilter', [filter]);
console.log(removed); // Log whether the filter is removed
} catch (err) {
console.error(err); // Handle errors that may occur
}
}
const filterId = '0x4e7ef166cd43f188b0f8f9e218966a8f' //'YOUR_FILTER_iD'
removeFilter(filterId)
from web3 import Web3
node_url = "CHAINSTACK_NODE_URL"
web3 = Web3(Web3.HTTPProvider(node_url))
def remove_filter(filter_id):
try:
removed = web3.eth.uninstall_filter(filter_id)
return removed
except Exception as e:
print(e)
filter_id = '0x0'
print(remove_filter(filter_id))
Use case
One use case for eth_uninstallFilter
is to optimize resource usage in a DApp. When a DApp needs to monitor events on the blockchain, it can create a filter using eth_newFilter or eth_newBlockFilter to listen for specific events or blocks.
However, once the DApp no longer needs to monitor these events or blocks, it can use eth_uninstallFilter
to stop watching for them. By doing so, the DApp can reduce the number of active filters and free up resources, such as network bandwidth and computational power, that would otherwise be used to maintain the filter.
For example, let's say that a DApp is monitoring incoming blocks, logs batches of 50 blocks, and then uses uninstallFilter
to remove the filter using.
Here is an implementation of this concept using ethers.js:
const ethers = require('ethers');
const NODE_URL = "CHAINSTACK_NODE_URL";
const provider = new ethers.JsonRpcProvider(NODE_URL);
const BLOCKS_TO_FETCH = 50;
const BLOCK_FETCH_INTERVAL_MS = 200;
async function getNewBlocks() {
const filterId = await provider.send("eth_newBlockFilter", []);
let blocks = [];
while (blocks.length < BLOCKS_TO_FETCH) {
const changes = await provider.send("eth_getFilterChanges", [filterId]);
//console.log(changes) // show the changes
if (changes.length === 0) {
await new Promise(resolve => setTimeout(resolve, BLOCK_FETCH_INTERVAL_MS)); // wait for new blocks
} else {
blocks = blocks.concat(changes);
}
}
const removeFilter = await provider.send("eth_uninstallFilter", [filterId]); // clean up filter
if (removeFilter) {
console.log(`We got 50 blocks, filter ${filterId} was removed.`)
return blocks
}
}
async function main() {
const fiftyBlocks = await getNewBlocks();
console.log(fiftyBlocks)
}
main()
This code fetches the latest 50 blocks using a filter and creates an array.
The BLOCKS_TO_FETCH
constant is set to 50, which represents the number of blocks to fetch.
The BLOCK_FETCH_INTERVAL_MS
constant is set to 200, which represents the time interval (in milliseconds) to wait for new blocks to arrive.
The getNewBlocks
function is defined to fetch the blocks. This function uses a loop to retrieve new blocks until it has fetched the desired number of blocks. The loop waits for new blocks to arrive for a certain amount of time before trying again.
Inside the getNewBlocks
function, the eth_newBlockFilter JSON-RPC method is called to create a new filter to watch for new blocks. The filter ID is returned and stored in the filterId
variable. An array stores the blocks fetched.
Inside the loop, the eth_getFilterChanges JSON-RPC method is called to retrieve any new blocks that have arrived since the filter was created. If there are no new blocks, the code waits a certain amount of time before trying again. If there are new blocks, they are stored in the blocks
array.
Once the blocks
array has reached the BLOCKS_TO_FETCH
limit, the filter is uninstalled using the eth_uninstallFilter
JSON-RPC method. The removeFilter
variable is set to true if the filter is successfully removed. If the filter is removed successfully, a message is logged to the console indicating that BLOCKS_TO_FETCH
blocks have been fetched and the filter was removed. The blocks array is returned as the result of the getNewBlocks
function.
The main function is defined to call the getNewBlocks
function and store the result in the fiftyBlocks
variable. The fiftyBlocks
variable is then logged to the console.
Try the eth_uninstallFilter
RPC method yourself
eth_uninstallFilter
RPC method yourself