Speculation rules: target_hint field

[nhiroki]

こんにちは TAG-さん!

I'm requesting a TAG review of target_hint field for speculation rules prerendering.

This extends speculation rules syntax to allow developers to specify the target_hint field.

This field provides a hint to indicate a target navigable where a prerendered page will eventually be activated. For example, when _blank is specified as a hint, a prerendered page can be activated for a navigable opened by window.open(). The field has no effect on prefetching.

• Explainer¹ (minimally containing user needs and example code): https://github.com/WICG/nav-speculation/blob/main/triggers.md#window-name-targeting-hints
• Specification URL: https://wicg.github.io/nav-speculation/speculation-rules.html
• Tests: https://wpt.fyi/results/speculation-rules/prerender
• User research: n/a
• Security and Privacy self-review²: This should be covered by the previous self-reviews for speculation rules and same-site prerendering. This feature just controls where a prerendered page is activated (current tab vs. new tab), and doesn’t expose new information.
  • https://github.com/WICG/nav-speculation/blob/main/speculation-rules-security-privacy-questionnaire.md
  • https://github.com/WICG/nav-speculation/blob/main/prerendering-same-site-security-privacy-questionnaire.md
• GitHub repo (if you prefer feedback filed there): https://github.com/WICG/nav-speculation
• Primary contacts (and their relationship to the specification):
  • Hiroki Nakagawa (@nhiroki), Google, contributor
  • Domenic Denicola (@domenic), Google, editor
  • Jeremy Roman (@jeremyroman), Google, editor
• Organization(s)/project(s) driving the specification: Google Chrome
• Key pieces of existing multi-stakeholder review or discussion of this specification:Prerendering and non-current target windows WICG/nav-speculation#168
• External status/issue trackers for this specification (publicly visible, e.g. Chrome Status): https://chromestatus.com/feature/5162540351094784

Further details:

• I have reviewed the TAG's Web Platform Design Principles
• Relevant time constraints or deadlines: We hope to start an origin trial with partners as soon as possible, so the sooner, the better.
• The group where the work on this specification is currently being done: WICG
• The group where standardization of this work is intended to be done (if current group is a community group or other incubation venue): WHATWG
• Major unresolved issues with or opposition to this specification: n/a
• This work is being funded by: Google

You should also know that...

n/a

We'd prefer the TAG provide feedback as (please delete all but the desired option):

☂️ open a single issue in our GitHub repo for the entire review

[torgo]

We're just taking a look at this today and noting that the section of the explainer doc you've linked to doesn't have explicit user needs indicated. Can you add something that indicates the user need you're trying to service here? I think it's something like "enhance the efficiency of pre-rendering so if the user's device does that pre-rendering work it's more likely to be used and therefore the user is more likely to have a performant experience" - is that correct?

[matatk]

Also, the explainer mentions the desire to deprecate this, when the engineering work is done. I appreciate it's hard to predict how the work will go, but is there any way to firm up the timeline in the explainer, or for the public to track when it's complete?