palantir/blueprint

Tables' `onVisibleCellChange` reports incorrect row indices.

Open

#3,341 opened on Feb 6, 2019

View on GitHub
 (7 comments) (0 reactions) (0 assignees)TypeScript (20,263 stars) (2,167 forks)batch import
P2Package: tableType: bughelp wanted

Description

Environment

  • Package version(s): 2.0.0+
  • Browser and OS versions: Tested Chrome on MacOS, seems irrelevant, though

Steps to reproduce

  1. Create a table that needs to scroll
  2. Add an onVisibleCellChage handler
  3. Note the rowIndices values passed to it on startup or scroll. Compare to the actual visible rows.

Example: https://jsfiddle.net/CrossEye/xf5cajyn/

Actual behavior

The rowIndices values do not correspond to the visible rows.

Expected behavior

These should match (with some possible fudging for rows which are only partially visible.)

Possible solution

I'm very new to blueprint. So I don't yet have any suggestions. I will try to dig into it soon, if this is a real bug and not just my own misinterpretation.

Notes

  • The example Fiddle is using table version 2.x. This is happening on the project I just joined in table version 3.2.0. I'm brand new to blueprint, and I couldn't get the Fiddle working with a 3.x. Any suggestions for how to do that would be appreciated. (The bundlers don't seem to get a web-appropriate version.)

  • I have not tested the column indices. But these clearly share a fair bit of code, so it seems quite possible that these are failing too.

Contributor guide

Tech stack
typescriptreact
Domain
frontend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
Familiarity with Blueprint's Table componentBasic understanding of React
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
45
Research direction
Investigate the onVisibleCellChange callback in the Blueprint Table component. Look in the source code (likely packages/table/src/) for where rowIndices are calculated during scroll. Compare the computed indices with the actual visible rows. Test with the provided JSFiddle example to reproduce. Also check if columnIndices have a similar issue. Check comments for any hints or partial fixes.