[🐞] visible tasks should run only when visible during CSR

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#8,502 opened on Mar 29, 2026 0 comments 0 reactions 0 assignees View on GitHub

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bug runtime V2

Dominant language: TypeScript
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Description

Which component is affected?

Qwik Runtime

Describe the bug

Now that qwik-loader can handle new qvisible listeners, change CSR so that visible tasks that want intersection-observer emit the attribute and qwikevents, and don't run them immediately

Reproduction

https://qwik.dev/playground/#f=5VjdThNREL7nKU5A0y10t9sWKNnQGi5MNFFjwHtpSysnlG1DWwqUXnvpi%2FgAPo8v4Cv4zcz52YWllsR4YzR2zzlz5sycM%2FPNN2aDptkojJqKL7%2FySeXXfHEF4%2B8s6q2KM3OAgT57Z4zjEbDklU5ROdcmOnK7wDupPC1vahCX3bogntTno6urzm2wH5ejgR4OA4LNcoSCHQSfK4KFrLzE5bOkdswc7BFtllCUPh4dv%2F7wqYSVAr6lLvq3rYW1KwJWzPpL%2F1DMoDxxWIhDefGdnWX72Mw40mU1jB9tztk2Ra0rld2BShAWf8G0LJKPBupd5%2B4W435vNiVu1hudYTrNlN051So%2F7IJ5XOLVruWtIxdb4zZdj1jmD%2F35%2FeuvH9%2FUoVC59kmPUBkVZJ4eVs2cQjXX4DrAfinlZGbKpbRQ%2B2zo1S%2F4WeXtNN%2BB3L8RHer2Qi8Pq%2Fh10%2BXy0mklVXYgNd4kS5YFE6zlM1lEW8XhmGF1EuA%2BbijkqRpLiNJnQDsUE7NExRUeCIFzQ6F6Zsi28Bk5huFPtwcZNpeFG78IomgygXhjwOHLR5FJwG3mlhAYzSOQgRMeT6BoWwVEeKoKqZPfY0in2%2FOex6v3MBt1O95glJOv1Y08EIp%2BxCNrrDginKpFpPQtsVwkTSByFVWLY3uiTU1JEiIlTpo1sJi52lwOSZmQ934qy7n3aW1y6G665MysTOd9cLfNtoupRwLoeVatT%2FTNitUUULlimW5503Y0C0%2FvE3UqjD14sfDvsQQdL5%2Bq5fJphfLU66kU2TWUSsytp1RkC5U%2BTNv7Wnzv68p9rX5Qu69um%2FzV6WSsr9AIdW8T15aMUWfQQ0S9UTS7qAq%2FCjsh6wh1GhLV3a5ubEQCVZRXvvNI1NZgMKAwAQdF4CQIwvGNQjzpM7XV7NAfvxpedc70DGRkL34pszfhRN8BhRMrgSlaOe%2FrL%2BfTRDViqKOJSzQ0OgUmqA66EZoZjyaayExCPQKo6nWfZuf6bHru9i1htgRjBR8UdPhFcOFfCqLHzjQajbzuThe%2B4EUf6IIO3mztJK8zx%2B%2B6w82Z7jS7gSWcvGz3J7DosD%2BAoLmq6WicqLCW0yuUSvTJkpHjPSRmzcyp6o5QVBFlXpuzTuSKdTF4ZV3YL%2FB5%2Fess8u%2FAaOyk%2BpKbjwTdI2Jut1GPYyqRA52i%2FNH%2FMgDRSDKc97sXehquu4McMcidf74%2F%2B9JsNp%2Fjy%2B4TvgDqn%2BfKExv4eaVu5Typ5z1pFHgy6MV78d5znLFKH9q2%2FzxXCsVtbCFL5GUovbxjDhZD9MUMAXUADB6MrbMnrZJC%2F%2FK%2FtWgHzX%2FSonFV%2Bfvd2W8

Steps to reproduce

click rerender => it renders the client-side clock immediately

System Info

web

Additional Information

No response

Contributor guide

Open the contributing guide

First steps

Read the whole issue, then the project's contributing guide.
Comment on the issue to say you are picking it up — it saves two people doing the same work.
Fork the repository and make your change on a branch.
Open a pull request that references the issue number.

Research direction

Start with the Qwik Runtime CSR path and reproduce the issue in the linked Qwik Playground example by clicking rerender. Trace how visible tasks are handled during CSR; done means intersection-observer tasks emit the qvisible attribute and qwikevents and do not run until the element is visible.

Written by the indexing model from the issue text.

Assessment

Tech stack: typescript
Domain: frontend
Issue type: Bug
Difficulty: 3/5
Estimated time: 1-2 days
Activity status: Quiet
Clarity: Mostly clear
Newbie friendliness: 48/100