docs(ui): document Range browser-default bounds (#201)

lib/ui/input_widgets_test.go

@@ -179,6 +179,16 @@ func TestInputFloatWidgets(t *testing.T) {
 	mustMatch(t, `^<input id="Jid\.[0-9]+" type="range" value="3.4">$`, got)
 }
 
+// TestRangeRendersExplicitBounds guards the documented workaround for the browser
+// range defaults: min, max and step passed as params render verbatim after the
+// value, letting a caller widen a domain the default 0..100 would otherwise clamp.
+func TestRangeRendersExplicitBounds(t *testing.T) {
+	_, rq := newCoreRequest(t)
+	sf := newTestSetter(150.0)
+	_, got := renderUI(t, rq, NewRange(sf), `min="0"`, `max="200"`, `step="0.5"`)
+	mustMatch(t, `^<input id="Jid\.[0-9]+" type="range" value="150" min="0" max="200" step="0.5">$`, got)
+}
+
 // TestInputFloat_ReconcilesConvertedValues verifies that number and range inputs
 // receive the canonical server value when a numeric adapter truncates or rounds
 // an input to the value that was already stored.

lib/ui/range.go

@@ -19,6 +19,13 @@ type Range struct{ InputFloat }
 // rendering or wire representation, so rendering, updating, or receiving one from
 // the browser cancels the [jaws.Request] with a cause wrapping
 // [jaws.ErrValueNotFinite].
+//
+// The widget emits no min, max, or step attribute of its own, so the browser
+// applies the HTML range defaults min="0", max="100", step="1". A bound value
+// outside that domain, or off the step grid, is silently clamped and rounded by
+// the browser, and the adjusted value is echoed back through the setter on the
+// next input event. Supply explicit min, max, and step attributes as render
+// params when the defaults do not cover the bound value's domain.
 func NewRange(g bind.Setter[float64]) *Range { return &Range{InputFloat{Setter: g}} }
 
 // JawsRender renders ui as an HTML range input.
@@ -28,7 +35,13 @@ func (u *Range) JawsRender(elem *jaws.Element, w io.Writer, params []any) error
 
 // Range renders an HTML range input.
 //
-// See [NewRange] for how a non-finite bound value is handled.
+// Supply min, max, and step attributes in params when the browser defaults
+// (min="0", max="100", step="1") do not cover the bound value's domain; a value
+// outside it is silently clamped and rounded by the browser. For example:
+//
+//	rw.Range(&v, `min="0"`, `max="200"`, `step="0.5"`)
+//
+// See [NewRange] for details and for how a non-finite bound value is handled.
 func (rw RequestWriter) Range(value any, params ...any) error {
 	return rw.NewUI(NewRange(bind.MakeSetterFloat64(value)), params...)
 }