GoogleChromeLabs/quicklink

Consider adding `rootMargin` to the Intersection Observer

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#14 opened on Dec 10, 2018

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 (13 comments) (1 reaction) (0 assignees)JavaScript (10,861 stars) (431 forks)batch import
enhancementgood first issuehelp wanted

Description

Feedback from @surma:

I feel like by default you should add a rootMargin to the IO to trigger the load before something comes into the viewport.

So, rootMargin defaults to "0px 0px 0px 0px", meaning the intersection will be computed between the root element's unmodified bounds rectangle and the target's bounds. This change would be made to https://github.com/GoogleChromeLabs/quicklink/blob/master/src/index.mjs#L21

Contributor guide

Tech stack
javascript
Domain
frontendperformance
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
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.
clear
Prerequisites
Intersection Observer APIJavaScriptquicklink library structure
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70
Research direction
Review the conversation in the comments to understand desired behavior. The change needs to be made in src/index.mjs around line 21 where the Intersection Observer is instantiated. Ensure the rootMargin option is exposed and defaults to '0px 0px 0px 0px' if not provided. Test that prefetching triggers earlier with a non zero rootMargin.