[jackielii]

The request says what it wants. Props is the normal page flow; returning an error breaks it.

The new docs page docs/rendering.md ("How a Request Is Rendered") lays out the whole model with a flow diagram. Start the review there.

Breaking

• No default target selector. Without WithTargetSelector, every request wants Page. htmx apps opt in with HTMXRenderTarget (htmx 1/2) or HTMXv4RenderTarget (htmx 4). The four htmx 2 examples now opt in.
• Selection goes through Is only. After Props returns no error, the framework asks the target Is(m) for each of the page's components and renders the one it matches, else Page.
  • Custom RenderTarget types take part in selection.
  • A target that matches several components is an error.
• Is has no side effects, and the "targeted but not handled" error is gone. Recognising a target and returning no error now renders Page.
• Mount checks component parameters for ambiguity, with Props' result types counted as provided.

New

• Is(OtherPage.Method): on an unmatched htmx target, matches another page's component by its exact generated id (htmxUnmatchedTarget, now in htmx.go).
• RenderComponent(c, more...): renders several components in order as one response, for updating several regions at once.
• Request args: WithRequestArgs(providers...) and a RequestArgs() []any page method.
  • Providers have the shape func(*http.Request[, *PageNode]) (T, error).
  • Each runs lazily, at most once per request, with the nearest page's provider winning.
  • A provider's error counts as an error from the method that needed the value.
• Components can now take per-request values and request args as well as Props' results.

Lint (tools/lint)

• idfor checks RenderTarget.Is arguments, flagging non-function arguments such as t.Is(p.Content()) and unmounted receivers.
• A new selector check flags a Mount with no WithTargetSelector when its pages' templates use htmx. It skips _test.go files and option lists it can't resolve.
• A new region check (.gsx) flags a page's component that puts another page's component id in id or hx-target/hx-target:inherited, chain form included. It isn't flagged when the page's Props handles Is for that component, and <hx-partial> isn't flagged. On eos at 225904df^ it reports all 12 sites across the 5 pages that commit fixed; at eos HEAD it reports nothing.
• A Mount whose options end in a spread (opts...) now builds its tree, so those pages are linted. Before, they were silently skipped.

Docs

• New: docs/rendering.md, with worked examples around Is and a section on targets that belong to another page. That section includes a middleware that retargets boosted navigation to body, and a development middleware that reports borrowed regions. Both are pinned by rendering_examples_test.go.
• Updated: htmx, dependency injection (a new request-args section), API, concepts, flows, error handling, gsx, templ and testing pages, both READMEs, the skill files and CLAUDE.md.
• The docs-site branch (already pushed, 379296a) adds the sidebar entry and the Mermaid plugin. Merging this PR to main triggers the deploy.

Choices for review

• Shadowing: a page's RequestArgs provider overrides an outer provider of the same type, rather than being an error.
• Docs examples: several that used RenderComponent now return several Props values instead, so they show the normal flow.

Verification

• go test ./..., golangci-lint and gopls are clean.
• All examples pass, including the lint-misuse snapshot, which now shows the selector finding.
• The tools/lint tests pass.
• The site builds with no dead links, and I checked in a browser that the diagram renders.
• eos at 798e84ed, run against this branch through a go.work: 344 packages ok, 0 failures, and the new linter reports nothing.

Release

v0.9.0 and tools/lint/v0.1.17, after review.

https://claude.ai/code/session_01Dp3Jmu2ePyCME2yG9yd672

[codecov]

Codecov Report

❌ Patch coverage is 95.42683% with 15 lines in your changes missing coverage. Please review.
✅ Project coverage is 95.32%. Comparing base (b5ffa6b) to head (4e54154).

Files with missing lines	Patch %	Lines
request_args.go	90.67%	7 Missing and 4 partials ⚠️
parse.go	97.26%	1 Missing and 1 partial ⚠️
id_for.go	50.00%	0 Missing and 1 partial ⚠️
struct_pages.go	98.91%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #36      +/-   ##
==========================================
+ Coverage   95.21%   95.32%   +0.10%     
==========================================
  Files          16       17       +1     
  Lines        1547     1754     +207     
==========================================
+ Hits         1473     1672     +199     
- Misses         44       49       +5     
- Partials       30       33       +3     

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