reactor-dsl

name	reactor-dsl
description	Pointer to the full Reactor API signatures index (`references/reactor.api.txt`). The 90% of DSL content — hooks, components, common factories, modifiers, theme tokens, gotchas, React-to-Reactor mapping — already lives in `reactor-getting-started`. Load this skill only when you need to verify a less-common signature against the alphabetized full index.

What this skill carries

The full alphabetized signatures index — every public factory, modifier, hook, theme token, and enum — lives at:

references/reactor.api.txt    (~12K tokens, ~650 lines)

It is the source of truth for the public API surface, regenerated from Reactor.dll by mur --regen-api.

In addition, the skill carries focused topical references for surfaces big enough to need their own page:

Topic	File	When to load
Keyed list reconciliation	references/keyed-lists.md	Choosing between IReactorKeyed, an explicit keySelector, and the three .WithKey(...) overloads; debugging a list that re-mounts on insert; understanding the bulk-replace bailout or the duplicate-key diagnostic. (Spec 042.)
Element refs and reference props	references/element-refs.md	Wiring UseElementRef<T>(), .Ref(...), .Target(...), accessibility relationships, XYFocus*, or custom descriptor .Reference / .ReferenceList entries. (Spec 057.)

When to load this skill

You probably don't need to. The reactor-getting-started skill carries the hooks table, the most-used factory signatures, the React-to-Reactor mapping, modifiers, theme tokens, and the critical gotchas — that's the 90% case.

Load this skill only when:

• You've checked reactor-getting-started and the factory/modifier you need isn't listed.
• You see a REACTOR_* analyzer ID and want to confirm the exact API surface in question.
• You're using a less-common control (DataGrid column overrides, AnnotatedScrollBar, AcrylicBrush parameters, etc.).

How to use the api index

Read the file once, scan for what you need, then keep working from memory. Do not re-page through it — the file is large and re-reading injects ~12K tokens per call. Per-pattern lookups are far cheaper than full re-reads.

If you only need to confirm whether a single name exists, use a grep for the symbol against the file rather than viewing it whole.

Fluent naming convention (callbacks)

Callback properties are named OnX on the record (e.g. OnClick, OnChanged, OnSelectedTagChanged). The matching fluent extension drops the leading On and is named after the event:

// Record property is OnClick — the fluent is .Click(...)
Button("Save").Click(() => Save());

// Record property is OnSelectedTagChanged — the fluent is .SelectedTagChanged(...)
NavigationView(...).SelectedTagChanged(tag => Navigate(tag));

This is intentional — C# doesn't allow an extension method to share a name with an instance property, so the On prefix lives on the property and the event-style name lives on the fluent. The two surfaces are equivalent; prefer the fluent for new code. Passing null to any OnX fluent clears the handler.

Common naming gotchas

• FlexElement record properties (set via with { ... }): Direction, JustifyContent, AlignItems, AlignContent, Wrap, ColumnGap, RowGap ⚠️ It's JustifyContent — NOT Justify. Example: FlexRow(a, b, c) with { JustifyContent = FlexJustify.SpaceBetween, ColumnGap = 8 }