feat(forms): SchemaForm renders every leaf as ExpressionField

frontend/src/forms/SchemaForm.test.tsx

@@ -5,7 +5,7 @@ import { render, screen } from "@testing-library/react";
 import { SchemaForm } from "./SchemaForm";
 import type { JsonSchemaObject } from "@/api/types";
 
-describe("SchemaForm", () => {
+describe("SchemaForm — ExpressionField-backed", () => {
   it("renders string fields from schema.properties with titles as labels", () => {
     const schema: JsonSchemaObject = {
       type: "object",
@@ -32,10 +32,7 @@ describe("SchemaForm", () => {
         <SchemaForm
           schema={schema}
           value={v}
-          onChange={(next) => {
-            onChange(next);
-            setV(next);
-          }}
+          onChange={(next) => { onChange(next); setV(next); }}
         />
       );
     }
@@ -45,24 +42,39 @@ describe("SchemaForm", () => {
     expect(last).toEqual({ url: "abc" });
   });
 
-  it("renders format:password as a password input", () => {
+  it("renders integer fields as expression fields storing string values", async () => {
     const schema: JsonSchemaObject = {
       type: "object",
-      properties: { pass: { type: "string", format: "password", title: "Password" } },
+      properties: { status: { type: "integer", title: "Status" } },
     };
-    render(<SchemaForm schema={schema} value={{}} onChange={() => {}} />);
-    expect(screen.getByLabelText(/password/i)).toHaveAttribute("type", "password");
+    const onChange = vi.fn();
+    function Wrapper() {
+      const [v, setV] = useState<Record<string, unknown>>({});
+      return (
+        <SchemaForm schema={schema} value={v} onChange={(next) => { onChange(next); setV(next); }} />
+      );
+    }
+    render(<Wrapper />);
+    await userEvent.type(screen.getByLabelText(/status/i), "200");
+    const last = onChange.mock.calls.at(-1)![0];
+    // SchemaForm stores strings; the graphAdapter coerces to number at save.
+    expect(last).toEqual({ status: "200" });
   });
 
-  it("renders format:code as a textarea", () => {
+  it("shows a live preview when previewInput is supplied", () => {
     const schema: JsonSchemaObject = {
       type: "object",
-      properties: { script: { type: "string", format: "code", title: "Script" } },
+      properties: { subject: { type: "string", title: "Subject" } },
     };
-    render(<SchemaForm schema={schema} value={{ script: "x = 1" }} onChange={() => {}} />);
-    const ta = screen.getByLabelText(/script/i);
-    expect(ta.tagName).toBe("TEXTAREA");
-    expect(ta).toHaveValue("x = 1");
+    render(
+      <SchemaForm
+        schema={schema}
+        value={{ subject: "hi {input.name}" }}
+        onChange={() => {}}
+        previewInput={{ name: "alice" }}
+      />,
+    );
+    expect(screen.getByTestId("expr-preview")).toHaveTextContent("hi alice");
   });
 
   it("marks required fields with an asterisk", () => {

frontend/src/forms/SchemaForm.tsx

@@ -1,17 +1,24 @@
-import type { ChangeEvent } from "react";
+import { forwardRef, useImperativeHandle, useRef } from "react";
 import type { JsonSchemaObject } from "@/api/types";
+import {
+  ExpressionField,
+  type ExpressionFieldHandle,
+  type ExpressionSchemaType,
+} from "@/expr/ExpressionField";
 
 interface Props {
   schema: JsonSchemaObject;
   value: Record<string, unknown>;
   onChange: (v: Record<string, unknown>) => void;
+  previewInput?: unknown;
+  onFieldFocus?: (handle: ExpressionFieldHandle) => void;
 }
 
-export function SchemaForm({ schema, value, onChange }: Props) {
+export function SchemaForm({ schema, value, onChange, previewInput, onFieldFocus }: Props) {
   const required = new Set(schema.required ?? []);
   const props = schema.properties ?? {};
 
-  function set(name: string, v: unknown) {
+  function set(name: string, v: string) {
     onChange({ ...value, [name]: v });
   }
 
@@ -21,59 +28,24 @@ export function SchemaForm({ schema, value, onChange }: Props) {
         const label = prop.title ?? name;
         const id = `sf-${name}`;
         const isRequired = required.has(name);
-        const current = value[name];
-
-        const control =
-          prop.type === "boolean" ? (
-            <input
-              id={id}
-              type="checkbox"
-              checked={!!current}
-              onChange={(e: ChangeEvent<HTMLInputElement>) => set(name, e.target.checked)}
-              className="rounded border-slate-700 bg-slate-950"
-            />
-          ) : prop.type === "number" || prop.type === "integer" ? (
-            <input
-              id={id}
-              type="number"
-              value={typeof current === "number" ? current : ""}
-              onChange={(e) => set(name, e.target.value === "" ? undefined : Number(e.target.value))}
-              className={inputCls}
-            />
-          ) : prop.format === "code" ? (
-            <textarea
-              id={id}
-              rows={8}
-              value={typeof current === "string" ? current : ""}
-              onChange={(e) => set(name, e.target.value)}
-              className={`${inputCls} font-mono text-xs`}
-              spellCheck={false}
-            />
-          ) : prop.format === "password" ? (
-            <input
-              id={id}
-              type="password"
-              value={typeof current === "string" ? current : ""}
-              onChange={(e) => set(name, e.target.value)}
-              className={inputCls}
-            />
-          ) : (
-            <input
-              id={id}
-              type="text"
-              value={typeof current === "string" ? current : ""}
-              onChange={(e) => set(name, e.target.value)}
-              className={inputCls}
-            />
-          );
-
+        const raw = toEditorString(value[name]);
+        const st = mapSchemaType(prop.type);
         return (
           <label key={name} htmlFor={id} className="block text-sm space-y-1">
             <span className="text-slate-300">
               {label}
               {isRequired && <span className="text-red-400 ml-0.5">*</span>}
             </span>
-            {control}
+            <SchemaExpressionField
+              id={id}
+              value={raw}
+              onChange={(v) => set(name, v)}
+              onFieldFocus={onFieldFocus}
+              previewInput={previewInput}
+              schemaType={st}
+              codeBlock={prop.format === "code"}
+              singleLine={prop.format !== "code"}
+            />
           </label>
         );
       })}
@@ -81,5 +53,42 @@ export function SchemaForm({ schema, value, onChange }: Props) {
   );
 }
 
-const inputCls =
-  "w-full rounded bg-slate-950 border border-slate-800 px-3 py-2 outline-none focus:border-brand-500 text-sm";
+const SchemaExpressionField = forwardRef<ExpressionFieldHandle, {
+  id: string; value: string; onChange: (v: string) => void;
+  previewInput?: unknown; schemaType?: ExpressionSchemaType;
+  singleLine?: boolean; codeBlock?: boolean;
+  onFieldFocus?: (handle: ExpressionFieldHandle) => void;
+}>(function SchemaExpressionField(props, _outer) {
+  const ref = useRef<ExpressionFieldHandle | null>(null);
+  useImperativeHandle(_outer, () => ref.current ?? { insertAtCaret: () => {}, focus: () => {} });
+  return (
+    <ExpressionField
+      ref={ref}
+      id={props.id}
+      value={props.value}
+      onChange={props.onChange}
+      previewInput={props.previewInput}
+      schemaType={props.schemaType}
+      singleLine={props.singleLine}
+      codeBlock={props.codeBlock}
+      onFocus={() => { if (ref.current) props.onFieldFocus?.(ref.current); }}
+    />
+  );
+});
+
+function mapSchemaType(t?: string): ExpressionSchemaType {
+  if (t === "integer") return "integer";
+  if (t === "number") return "number";
+  if (t === "boolean") return "boolean";
+  return "string";
+}
+
+// Value stored in state may be a number/bool if it round-tripped from the
+// backend already coerced. Render it as its literal string form so the user
+// can edit it as an expression.
+function toEditorString(v: unknown): string {
+  if (v === undefined || v === null) return "";
+  if (typeof v === "string") return v;
+  if (typeof v === "number" || typeof v === "boolean") return String(v);
+  return JSON.stringify(v);
+}