stevenbenner/jquery-powertip

Uncaught TypeError: Cannot read property 'data' of null

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#169 opened on Jul 27, 2018

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BugHelp Wanted

Description

I'm running powertip 1.3.1 and got the following exception:

jquery.powertip.js:964 Uncaught TypeError: Cannot read property 'data' of null
    at hideTip (jquery.powertip.js:964)
    at showTip (jquery.powertip.js:855)
    at HTMLDivElement.queueTipInit (jquery.powertip.js:829)
    at Function.dequeue (js_thirdp_libs.js:20)
    at HTMLDivElement.r.complete (js_thirdp_libs.js:20)
    at l (js_thirdp_libs.js:20)
    at Object.fireWith [as resolveWith] (js_thirdp_libs.js:20)
    at a (js_thirdp_libs.js:20)
    at v.fx.tick (js_thirdp_libs.js:20)

This was occuring while I was hovering over something with a powerTip, and an event comes in which causes another powerTip to open. It's not entirely consistent, and I believe it has todo with the opening and closing state of the hovered powertip.

As shown in the debugger below, it looks like isTipOpen is true, and it isn't closing, but activeHover is null.

image

Contributor guide

Tech stack
javascript
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.
half day
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
basic JavaScriptjQuery basics
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
45
Research direction
Investigate the `hideTip` function in `jquery.powertip.js` around line 964. The error occurs when `activeHover` is null but `isTipOpen` is true, suggesting a race condition in tooltip state management. Focus on the logic that sets and clears `activeHover` and `isTipOpen` during show/hide transitions. Reproduce by rapidly hovering over elements to trigger overlapping tooltip events.