fix: restore inspector template hot reload

bliss-cli/live-editor/artifact-editor.eta

@@ -0,0 +1,57 @@
+<article data-bliss-artifact-editor
+  data-kind="<%= it.kind %>" data-id="<%= it.artifact.id %>"
+  data-structure-id="<%= it.artifact.structure_id %>" data-method="<%= it.artifact.verb || '' %>"
+  class="border-2 border-black bg-white text-black shadow-[4px_4px_0_#000]">
+  <header class="flex items-center gap-2 border-b-4 border-double border-black p-3">
+    <strong class="min-w-0 flex-1 truncate"><% if (it.kind === 'route') { %><%= it.artifact.verb %> <%= it.artifact.path %><% } else { %><%= it.artifact.name %><% } %></strong>
+    <span class="text-xs uppercase"><%= it.kind %></span><span data-status class="text-xs"></span>
+  </header>
+  <div class="p-3">
+    <% if (it.kind === 'route' && it.artifact.verb !== 'GET') { %>
+      <p class="mb-2 border border-amber-700 bg-amber-100 p-2 text-sm">Saving does not replay this <%= it.artifact.verb %> route.</p>
+    <% } %>
+    <label class="block text-xs font-bold uppercase tracking-widest"><%= it.kind === 'route' ? 'Handler' : 'Template' %></label>
+    <div data-editor="<%= it.kind === 'route' ? 'handler' : 'content' %>" data-mode="<%= it.kind === 'route' ? 'javascript' : 'html' %>" class="h-[min(55vh,34rem)] w-full border-2 border-black"><%= it.kind === 'route' ? it.artifact.handler : it.artifact.content %></div>
+    <% if (it.kind === 'template') { %>
+      <details class="mt-3" open>
+        <summary class="cursor-pointer text-xs font-bold uppercase tracking-widest">Rendering test</summary>
+        <div data-editor="test_object" data-mode="javascript" class="mt-1 h-32 w-full border-2 border-black"><%= it.artifact.test_object || '' %></div>
+        <iframe data-template-test title="Template rendering test" src="/workshop/<%= it.artifact.structure_id %>/template/<%= it.artifact.id %>/preview" class="mt-2 h-64 w-full border-2 border-black"></iframe>
+      </details>
+    <% } %>
+    <button data-save type="button" class="mt-3 border-2 border-black bg-white px-3 py-2 font-bold shadow-[3px_3px_0_#000]">Save</button>
+  </div>
+</article>
+<script>
+(function () {
+  const card = document.currentScript.previousElementSibling;
+  if (!card || card.dataset.ready) return;
+  card.dataset.ready = "true";
+  const editors = Object.fromEntries([...card.querySelectorAll("[data-editor]")].map((node) => {
+    const editor = ace.edit(node);
+    editor.setTheme("ace/theme/monokai");
+    editor.session.setMode(`ace/mode/${node.dataset.mode}`);
+    return [node.dataset.editor, editor];
+  }));
+  card.querySelector("[data-save]").onclick = async () => {
+    const status = card.querySelector("[data-status]");
+    const { kind, id, structureId } = card.dataset;
+    status.textContent = "Saving…";
+    const body = kind === "route"
+      ? { handler: editors.handler.getValue() }
+      : { content: editors.content.getValue(), test_object: editors.test_object.getValue() };
+    const response = await fetch(`/workshop/${structureId}/${kind}/${id}`, {
+      method: "PUT", headers: { "Content-Type": "application/json" }, body: JSON.stringify(body),
+    });
+    if (!response.ok) return void (status.textContent = "Save failed");
+    status.textContent = "Saved";
+    if (kind === "template") {
+      const frame = card.querySelector("[data-template-test]");
+      frame.src = `${frame.src.split("?")[0]}?t=${Date.now()}`;
+    }
+    document.dispatchEvent(new CustomEvent("bliss:source-saved", {
+      detail: { kind, id, method: kind === "route" ? card.dataset.verb : undefined },
+    }));
+  };
+})();
+</script>

bliss-cli/live-editor/install.js

@@ -40,6 +40,7 @@ const templates = [
   ["inspector/slideout", "slideout.eta"],
   ["inspector/route_editor", "route-editor.eta"],
   ["inspector/template_editor", "template-editor.eta"],
+  ["inspector/artifact_editor", "artifact-editor.eta"],
 ];
 for (const [name, filename] of templates) {
   let template = state.templates.find((item) => item.name === name);

bliss-cli/live-editor/route-editor.js

@@ -1,8 +1,7 @@
 function handler(req, res) {
   const sql = require("db")("bliss").sql;
-  const sourceRoute = sql
-    .prepare("SELECT * FROM routes WHERE id = ?")
-    .get(req.params.id);
-  if (!sourceRoute) return res.status(404).send("Route not found");
-  res.render("inspector/route_editor", { sourceRoute });
+  const kind = "route";
+  const artifact = sql.prepare("SELECT * FROM routes WHERE id = ?").get(req.params.id);
+  if (!artifact) return res.status(404).send("Route not found");
+  res.render("inspector/artifact_editor", { kind, artifact });
 }

bliss-cli/live-editor/template-editor.js

@@ -1,8 +1,7 @@
 function handler(req, res) {
   const sql = require("db")("bliss").sql;
-  const sourceTemplate = sql
-    .prepare("SELECT * FROM templates WHERE id = ?")
-    .get(req.params.id);
-  if (!sourceTemplate) return res.status(404).send("Template not found");
-  res.render("inspector/template_editor", { sourceTemplate });
+  const kind = "template";
+  const artifact = sql.prepare("SELECT * FROM templates WHERE id = ?").get(req.params.id);
+  if (!artifact) return res.status(404).send("Template not found");
+  res.render("inspector/artifact_editor", { kind, artifact });
 }

db.js

@@ -2,6 +2,7 @@ const fs = require("fs");
 const path = require("path");
 const betterSqlite3 = require("better-sqlite3");
 const { LRUCache } = require("lru-cache");
+const { randomUUID } = require("node:crypto");
 const { Eta } = require("eta");
 const cheerio = require("cheerio");
 
@@ -95,8 +96,37 @@ function getAllRoutes() {
 }
 
 const templateCache = new LRUCache({ max: 100 });
+const templateContextCache = new LRUCache({ max: 2000, ttl: 30 * 60 * 1000 });
 
-function annotateTemplateHtml(html, template) {
+// The inspector needs the values that produced each rendered template, not a
+// fresh request's values.  Contexts frequently contain helpers (such as
+// `route`) or cyclic request objects, neither of which belongs in HTML.  Keep
+// the JSON-shaped portion and omit the rest rather than making a page fail to
+// render just because it cannot be inspected.
+function inspectableContext(data) {
+  const seen = new WeakSet();
+  try {
+    return JSON.parse(
+      JSON.stringify(data ?? {}, (_key, value) => {
+        if (typeof value === "function" || typeof value === "undefined") {
+          return undefined;
+        }
+        if (typeof value === "object" && value !== null) {
+          if (seen.has(value)) return undefined;
+          seen.add(value);
+        }
+        return value;
+      }),
+    );
+  } catch (_) {
+    return {};
+  }
+}
+
+function annotateTemplateHtml(html, template, data) {
+  const context = inspectableContext(data);
+  const contextId = randomUUID();
+  templateContextCache.set(contextId, { templateId: String(template.id), context });
   function annotate($, element) {
     const current = $(element).attr("data-bliss-templates");
     let templates = [];
@@ -109,10 +139,20 @@ function annotateTemplateHtml(html, template) {
       templates.push({ id: String(template.id), name: template.name });
     }
     $(element).attr("data-bliss-templates", JSON.stringify(templates));
+    const rawContextIds = $(element).attr("data-bliss-template-context-ids");
+    let contextIds = {};
+    if (rawContextIds) {
+      try {
+        contextIds = JSON.parse(rawContextIds);
+      } catch (_) {}
+    }
+    contextIds[String(template.id)] = contextId;
+    $(element).attr("data-bliss-template-context-ids", JSON.stringify(contextIds));
     if (!$(element).attr("data-bliss-template-id")) {
       $(element).attr({
         "data-bliss-template-id": String(template.id),
         "data-bliss-template-name": template.name,
+        "data-bliss-template-context-id": contextId,
       });
     }
   }
@@ -143,7 +183,7 @@ function getTemplater(structId) {
       const html = etaRender.call(this, templateName, data, meta);
       if (typeof templateName !== "string") return html;
       const template = getTemplateByName(structId, templateName);
-      return template ? annotateTemplateHtml(html, template) : html;
+      return template ? annotateTemplateHtml(html, template, data) : html;
     };
     templateCache.set(structId, etaInstance);
   }
@@ -302,6 +342,12 @@ function getTemplate(templateId) {
   return db.prepare("SELECT * from templates where id = ?").get(templateId);
 }
 
+function getInspectableTemplateContext(contextId, templateId) {
+  const entry = templateContextCache.get(contextId);
+  if (!entry || entry.templateId !== String(templateId)) return null;
+  return entry.context;
+}
+
 function getTemplateContentByName(structId, name) {
   return db
     .prepare(
@@ -736,6 +782,7 @@ module.exports = {
   getTemplater,
   getTemplates,
   getTemplate,
+  getInspectableTemplateContext,
   getTemplateContentByName,
   getTemplateByName,
   createTemplate,

index.js

@@ -464,6 +464,29 @@ function renderTemplate(structureId, templateName, context) {
   return model.getTemplater(structureId).render(templateName, context);
 }
 
+// Re-render one saved template instance with the JSON-safe values captured on
+// that instance when the page was first produced.  This is deliberately a
+// platform endpoint rather than a user route: editing a template must not
+// replay a route handler (and its side effects) just to update the markup.
+app.post("/_bliss/render-template", (req, res) => {
+  const structureId = String(req.body?.structureId ?? "");
+  const templateId = String(req.body?.templateId ?? "");
+  const template = model.getTemplate(templateId);
+  if (!template || String(template.structure_id) !== structureId) {
+    return res.status(404).send("Template not found");
+  }
+
+  const structure = model.getStructure(structureId);
+  const savedContext = model.getInspectableTemplateContext(
+    req.body?.contextId,
+    templateId,
+  );
+  if (!savedContext) return res.status(410).send("Template context expired; refresh the page");
+  const context = { ...savedContext };
+  context.route = makeRoute(structure);
+  return res.type("html").send(renderTemplate(structureId, template.name, context));
+});
+
 // Provenance for a rendered response: GET routes are re-embeddable, so they
 // carry the copy-embed snippet; other verbs don't.
 function sourceFor(route, req, templateName = null) {

public/js/bliss_inspector.js

@@ -36,6 +36,14 @@
       : [];
   }
 
+  function contextIdFor(element, templateId) {
+    try {
+      const ids = JSON.parse(element.dataset.blissTemplateContextIds || "{}");
+      if (Object.hasOwn(ids, String(templateId))) return ids[String(templateId)];
+    } catch (_) {}
+    return element.dataset.blissTemplateContextId || null;
+  }
+
   function inventory() {
     const items = [];
     for (const owner of routeElements()) {
@@ -89,44 +97,107 @@
     }
   }
 
+  async function replaceBody(html) {
+    const ui = [...document.body.querySelectorAll(":scope > [data-bliss-ui]")];
+    const next = new DOMParser().parseFromString(html, "text/html");
+    for (const attribute of [...document.body.attributes]) {
+      document.body.removeAttribute(attribute.name);
+    }
+    for (const attribute of [...next.body.attributes]) {
+      document.body.setAttribute(attribute.name, attribute.value);
+    }
+    document.body.innerHTML = next.body.innerHTML;
+    for (const node of ui) document.body.appendChild(node);
+    htmx.process(document.body);
+  }
+
   async function refreshElement(element) {
     if (element.dataset.blissMethod !== "GET") return;
     const url = element.dataset.blissRequestUrl;
     if (!url) return;
 
     if (element === document.body) {
-      const ui = [...document.body.querySelectorAll(":scope > [data-bliss-ui]")];
-      const response = await fetch(url, { headers: { "HX-Request": "true" } });
+      // A page root must be fetched as a document.  Asking for an HTMX
+      // fragment here used to parse an empty <body> and erase the page.
+      const response = await fetch(url);
       if (!response.ok) throw new Error(`GET ${url} returned ${response.status}`);
-      const next = new DOMParser().parseFromString(await response.text(), "text/html");
-      for (const attribute of [...document.body.attributes]) {
-        document.body.removeAttribute(attribute.name);
-      }
-      for (const attribute of [...next.body.attributes]) {
-        document.body.setAttribute(attribute.name, attribute.value);
-      }
-      document.body.innerHTML = next.body.innerHTML;
-      for (const node of ui) document.body.appendChild(node);
-      htmx.process(document.body);
+      await replaceBody(await response.text());
       return;
     }
 
     await htmx.ajax("GET", url, { target: element, swap: "outerHTML" });
   }
 
+  function outermost(elements, selector) {
+    const set = new Set(elements);
+    return elements.filter((element) => {
+      let parent = element.parentElement;
+      while (parent) {
+        if (set.has(parent) && parent.matches(selector)) return false;
+        parent = parent.parentElement;
+      }
+      return true;
+    });
+  }
+
+  async function refreshTemplateElement(element, templateId, previousRoots = []) {
+    const response = await fetch("/_bliss/render-template", {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({
+        structureId: element.closest(ROUTE_SELECTOR)?.dataset.blissStructureId,
+        templateId,
+        contextId: contextIdFor(element, templateId),
+      }),
+    });
+    if (!response.ok) {
+      throw new Error(`Template ${templateId} returned ${response.status}`);
+    }
+    const html = await response.text();
+    if (element === document.body) return replaceBody(html);
+    const fragment = document.createElement("template");
+    fragment.innerHTML = html;
+    // A template may legally have several top-level nodes.  They share one
+    // captured context id, so replace that one render as a group instead of
+    // rendering the same template once per root and duplicating its output.
+    for (const root of previousRoots) {
+      if (root !== element && root.isConnected) root.remove();
+    }
+    element.replaceWith(fragment.content);
+    htmx.process(document.body);
+  }
+
+  function templateRefreshGroups(templateId) {
+    const elements = outermost(
+      templateElements().filter((element) =>
+        matches(element, { kind: "template", id: templateId }),
+      ),
+      TEMPLATE_SELECTOR,
+    );
+    const groups = new Map();
+    for (const element of elements) {
+      const contextId = contextIdFor(element, templateId);
+      const key = contextId || `element:${Math.random()}`;
+      if (!groups.has(key)) groups.set(key, []);
+      groups.get(key).push(element);
+    }
+    return [...groups.values()];
+  }
+
   async function refreshSources({ kind, id, method }) {
     if (method && method !== "GET") return;
-    const elements = routeElements().filter((element) => {
-      if (kind === "template") {
-        return templateElements().some(
-          (template) =>
-            matches(template, { kind: "template", id }) &&
-            template.closest(ROUTE_SELECTOR) === element,
-        );
-      }
-      return matches(element, { kind, id });
-    });
-    const settled = await Promise.allSettled(elements.map(refreshElement));
+    const elements =
+      kind === "template"
+        ? templateRefreshGroups(id)
+        : outermost(
+            routeElements().filter((element) => matches(element, { kind, id })),
+            ROUTE_SELECTOR,
+          );
+    const refresh =
+      kind === "template"
+        ? (group) => refreshTemplateElement(group[0], id, group)
+        : refreshElement;
+    const settled = await Promise.allSettled(elements.map(refresh));
     const failure = settled.find((result) => result.status === "rejected");
     if (failure) console.error("Bliss live refresh failed", failure.reason);
     publishInventory();