[Apps][Examples] Create a websocket to listen for a new block
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Authored by emack on Aug 9 2023, 01:40.

Details

Reviewers

bytesofman

Group Reviewers

Restricted Project

Summary

T3203

This is useful for app devs looking to build network visualizers which need to listen for new incoming blocks, without having to make direct RPC calls to the node.

The example uses a chronik websocket to listen for BlockConnected events and then unsubscribes and closes upon detection.

Test Plan

npm test
npm run listenForNewBlock <address>

Diff Detail

Repository

rABC Bitcoin ABC

Branch

wsNewBlock

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Unit

No Test Coverage

Build Status

Buildable 24713
Build 49018: Build Diff	app-dev-examples
Build 49017: arc lint + arc unit

Event Timeline

emack created this revision.Aug 9 2023, 01:40

Herald added a reviewer: Restricted Project. · View Herald TranscriptAug 9 2023, 01:40

emack requested review of this revision.Aug 9 2023, 01:40

Harbormaster completed remote builds in B24713: Diff 41756.Aug 9 2023, 01:41

Fabien added a subscriber: Fabien.Aug 9 2023, 12:02

Fabien added inline comments.

apps/examples/scripts/listenForNewBlock.js
45	why do you need the address to subscribe to new blocks ?

bytesofman added inline comments.Aug 9 2023, 17:03

apps/examples/scripts/listenForNewBlock.js
45	I haven't checked this out in chronik or chronik-client, but I have tried to subscribe to a websocket without an address and it doesn't work fix tho should be to allow this in chronik-client

emack marked 2 inline comments as done.Aug 10 2023, 07:08

emack added inline comments.

apps/examples/scripts/listenForNewBlock.js
45	why do you need the address to subscribe to new blocks ? I just tested it using only `ws.waitForOpen()` to listen for over 2 consecutive blocks without an address subscription and it didn't pick up the BlockConnected (or any other) events. I can put in a diff on this once we're done with the big url cycling refactor in D14269.

Fabien added inline comments.Aug 10 2023, 07:40

apps/examples/scripts/listenForNewBlock.js
45	Is that on chronik-client or on chronik side ?

emack marked an inline comment as done.Aug 10 2023, 09:02

emack added inline comments.

apps/examples/scripts/listenForNewBlock.js
45	Is that on chronik-client or on chronik side ? Tobias said the ability to subscribe to block updates is already in the chronik-embedded node software, so the client just needs to be updated to use it