How to retrive data stored in a block

Question

I have stored an information on chain and I want to access that information using RPC call.

I used the following code and provided the hash created.

const signedBlock = await api.rpc.chain.getBlock(blockHash);

How can I retrieve/see the data I uploaded to that block?

If have uploaded "string" in that block. How can i get it back as "string" by providing the block hash

Answer 1

With your instruction

const signedBlock = await api.rpc.chain.getBlock(blockHash);

You have all the information on the Block, you can get now all the extrinsics from the block

signedBlock.block.extrinsics.forEach((ex, index) => {
    console.log("---extrinsic----");
    console.log(ex.toHuman());
});

This will print all the extrinsics on the block and the information, you will have to find yours. If you know the pallet of your extrinsic you can filter .

const { method: { args, method, section } } = ex;
const pallet = ex.method.section;

Or if you know the Extrinsic ID you can filter by the extrinsic ID to get it:

const extrinsicId = signedBlock.block.header.number + "-" + index