Scanning Blocks

To implement a simple function to wait for a given block:

TypeScript

async function waitForBlock(blockHeight: number) {
    let latestBlock = (await networkStatus()).current_block_identifier.index
    while (true) {
        if (blockHeight <= latestBlock)
            return await block(blockHeight)
        await sleep(10000)
        latestBlock = (await networkStatus()).current_block_identifier.index
    }
}

Python

def wait_for_block(block_index):
    """
    Checks if block with given index exist
    Once the /block response is succesful - returns the response
    Otherwise, retries fetching it with 10 seconds delay
    """

    latest_block = network_status()["current_block_identifier"]["index"]
    while True:
        if block_index <= latest_block:
            return block(block_index)
        sleep(10)
        latest_block = network_status()["current_block_identifier"]["index"]

It can be used to scan blocks like this:

TypeScript

let latestBlockHeight = (await network_status()).current_block_identifier.index
while (true) {
    const lastBlock = waitForBlock(latestBlockHeight)
    
    # some processing according to business logic
    
    latestBlockHeight += 1
}

Python

latest_block = network_status()["current_block_identifier"]["index"]
while True:
    last_block = wait_for_block(latest_block)
    
    # some processing according to business logic
    
    latest_block += 1