meteor · dupontbertrand · Apr 20, 2026 · Apr 20, 2026 · Apr 20, 2026 · Apr 20, 2026
diff --git a/packages/caching-html-compiler/caching-html-compiler.js b/packages/caching-html-compiler/caching-html-compiler.js
@@ -115,14 +115,17 @@ CachingHtmlCompiler = class CachingHtmlCompiler extends CachingCompiler {
         }
       });
 
-      // Add JavaScript code to set attributes on body
+      // Add JavaScript code to set attributes on body.
+      // Guarded with Meteor.isClient because document.body doesn't exist on the server.
       allJavaScript +=
-`Meteor.startup(function() {
-  var attrs = ${JSON.stringify(compileResult.bodyAttrs)};
-  for (var prop in attrs) {
-    document.body.setAttribute(prop, attrs[prop]);
-  }
-});
+`if (Meteor.isClient) {
+  Meteor.startup(function() {
+    var attrs = ${JSON.stringify(compileResult.bodyAttrs)};
+    for (var prop in attrs) {
+      document.body.setAttribute(prop, attrs[prop]);
+    }
+  });
+}
 `;
     }
 

diff --git a/packages/templating-compiler/compile-templates.js b/packages/templating-compiler/compile-templates.js
@@ -1,7 +1,8 @@
 /* global CachingHtmlCompiler TemplatingTools */
 Plugin.registerCompiler({
   extensions: ['html'],
-  archMatching: 'web',
+  // archMatching removed — compile for all architectures (web + os/server)
+  // so that Template definitions are available server-side for SSG rendering.
   isTemplate: true,
 }, () => new CachingHtmlCompiler(
   'templating',

diff --git a/packages/templating-runtime/package.js b/packages/templating-runtime/package.js
@@ -11,9 +11,10 @@ Package.onUse(function (api) {
   // XXX would like to do the following only when the first html file
   // is encountered
 
-  api.export('Template', 'client');
+  // Export Template to both client and server — server needs it for SSG rendering.
+  api.export('Template');
 
-  api.addFiles('templating.js', 'client');
+  api.addFiles('templating.js');
 
   // html_scanner.js emits client code that calls Meteor.startup and
   // Blaze, so anybody using templating (eg apps) need to implicitly use
@@ -27,13 +28,14 @@ Package.onUse(function (api) {
     'meteor',
     'blaze@3.0.0',
     'spacebars@2.0.0'
-  ], 'client');
+  ]);
 
   // to be able to compile dynamic.html. this compiler is used
   // only inside this package and it should not be implied to not
   // conflict with other packages providing .html compilers.
   api.use('templating-compiler@2.0.0');
 
+  // dynamic template support is client-only (requires DOM)
   api.addFiles([
     'dynamic.html',
     'dynamic.js'

diff --git a/packages/templating-runtime/templating.js b/packages/templating-runtime/templating.js
@@ -10,6 +10,7 @@ Template = Blaze.Template;
 const RESERVED_TEMPLATE_NAMES = "__proto__ name".split(" ");
 
 // Check for duplicate template names and illegal names that won't work.
+// This is server-safe — no DOM dependency.
 Template.__checkName = function (name) {
   // Some names can't be used for Templates. These include:
   //  - Properties Blaze sets on the Template object.
@@ -26,157 +27,170 @@ Template.__checkName = function (name) {
   }
 };
 
-let shownWarning = false;
-
-// XXX COMPAT WITH 0.8.3
-Template.__define__ = function (name, renderFunc) {
-  Template.__checkName(name);
-  Template[name] = new Template(`Template.${name}`, renderFunc);
-  // Exempt packages built pre-0.9.0 from warnings about using old
-  // helper syntax, because we can.  It's not very useful to get a
-  // warning about someone else's code (like a package on Atmosphere),
-  // and this should at least put a bit of a dent in number of warnings
-  // that come from packages that haven't been updated lately.
-  Template[name]._NOWARN_OLDSTYLE_HELPERS = true;
-
-  // Now we want to show at least one warning so that people get serious about
-  // updating away from this method.
-  if (!shownWarning) {
-    shownWarning = true;
-    console.warn("Your app is using old Template definition that is scheduled to be removed with Blaze 3.0, please check your app and packages for use of: Template.__define__");
-  }
-};
-
-// Define a template `Template.body` that renders its
-// `contentRenderFuncs`.  `<body>` tags (of which there may be
-// multiple) will have their contents added to it.
-
-/**
- * @summary The [template object](#Template-Declarations) representing your `<body>`
- * tag.
- * @locus Client
- */
-Template.body = new Template('body', function () {
-  const view = this;
-  return Template.body.contentRenderFuncs.map((func) => func.apply(view));
-});
-Template.body.contentRenderFuncs = []; // array of Blaze.Views
-Template.body.view = null;
-
-Template.body.addContent = function (renderFunc) {
-  Template.body.contentRenderFuncs.push(renderFunc);
-};
-
-// This function does not use `this` and so it may be called
-// as `Meteor.startup(Template.body.renderIntoDocument)`.
-Template.body.renderToDocument = function () {
-  // Only do it once.
-  if (Template.body.view)
-    return;
-
-  const view = Blaze.render(Template.body, document.body);
-  Template.body.view = view;
-};
-
-Template.__pendingReplacement = []
-
-let updateTimeout = null;
-
-// Simple HMR integration to re-render all of the root views
-// when a template is modified. This function can be overridden to provide
-// an alternative method of applying changes from HMR.
-Template._applyHmrChanges = function (templateName) {
-  if (updateTimeout) {
-    return;
-  }
-
-  // debounce so we only re-render once per rebuild
-  updateTimeout = setTimeout(() => {
-    updateTimeout = null;
-
-    for (let i = 0; i < Template.__pendingReplacement.length; i++) {
-      delete Template[Template.__pendingReplacement[i]];
+// Everything below this point requires DOM and is client-only.
+// On the server, Template is available as a registry for compiled templates
+// (used by Blaze.toHTML / StaticRender for SSG), but body rendering,
+// HMR, and DOM attachment are skipped.
+
+if (Meteor.isClient) {
+
+  let shownWarning = false;
+
+  // XXX COMPAT WITH 0.8.3
+  Template.__define__ = function (name, renderFunc) {
+    Template.__checkName(name);
+    Template[name] = new Template(`Template.${name}`, renderFunc);
+    // Exempt packages built pre-0.9.0 from warnings about using old
+    // helper syntax, because we can.  It's not very useful to get a
+    // warning about someone else's code (like a package on Atmosphere),
+    // and this should at least put a bit of a dent in number of warnings
+    // that come from packages that haven't been updated lately.
+    Template[name]._NOWARN_OLDSTYLE_HELPERS = true;
+
+    // Now we want to show at least one warning so that people get serious about
+    // updating away from this method.
+    if (!shownWarning) {
+      shownWarning = true;
+      console.warn("Your app is using old Template definition that is scheduled to be removed with Blaze 3.0, please check your app and packages for use of: Template.__define__");
+    }
+  };
+
+  // Define a template `Template.body` that renders its
+  // `contentRenderFuncs`.  `<body>` tags (of which there may be
+  // multiple) will have their contents added to it.
+
+  /**
+   * @summary The [template object](#Template-Declarations) representing your `<body>`
+   * tag.
+   * @locus Client
+   */
+  Template.body = new Template('body', function () {
+    const view = this;
+    return Template.body.contentRenderFuncs.map((func) => func.apply(view));
+  });
+  Template.body.contentRenderFuncs = []; // array of Blaze.Views
+  Template.body.view = null;
+
+  Template.body.addContent = function (renderFunc) {
+    Template.body.contentRenderFuncs.push(renderFunc);
+  };
+
+  // This function does not use `this` and so it may be called
+  // as `Meteor.startup(Template.body.renderIntoDocument)`.
+  Template.body.renderToDocument = function () {
+    // Only do it once.
+    if (Template.body.view)
+      return;
+
+    const view = Blaze.render(Template.body, document.body);
+    Template.body.view = view;
+  };
+
+  Template.__pendingReplacement = [];
+
+  let updateTimeout = null;
+
+  // Simple HMR integration to re-render all of the root views
+  // when a template is modified. This function can be overridden to provide
+  // an alternative method of applying changes from HMR.
+  Template._applyHmrChanges = function (templateName) {
+    if (updateTimeout) {
+      return;
     }
 
-    Template.__pendingReplacement = [];
-
-    const views = Blaze.__rootViews.slice();
-    for (let i = 0; i < views.length; i++) {
-      const view = views[i];
-      if (view.destroyed) {
-        continue;
-      }
+    // debounce so we only re-render once per rebuild
+    updateTimeout = setTimeout(() => {
+      updateTimeout = null;
 
-      const renderFunc = view._render;
-      let parentEl;
-      if (view._domrange && view._domrange.parentElement) {
-        parentEl = view._domrange.parentElement;
-      } else if (view._hmrParent) {
-        parentEl = view._hmrParent;
+      for (let i = 0; i < Template.__pendingReplacement.length; i++) {
+        delete Template[Template.__pendingReplacement[i]];
       }
 
-      let comment;
-      if (view._hmrAfter) {
-        comment = view._hmrAfter;
-      } else {
-        const first = view._domrange.firstNode();
-        comment = document.createComment('Blaze HMR PLaceholder');
-        parentEl.insertBefore(comment, first);
-      }
+      Template.__pendingReplacement = [];
 
-      view._hmrAfter = null;
-      view._hmrParent = null;
+      const views = Blaze.__rootViews.slice();
+      for (let i = 0; i < views.length; i++) {
+        const view = views[i];
+        if (view.destroyed) {
+          continue;
+        }
 
-      if (view._domrange) {
-        Blaze.remove(view);
-      }
+        const renderFunc = view._render;
+        let parentEl;
+        if (view._domrange && view._domrange.parentElement) {
+          parentEl = view._domrange.parentElement;
+        } else if (view._hmrParent) {
+          parentEl = view._hmrParent;
+        }
 
-      try {
-        if (view === Template.body.view) {
-          const newView = Blaze.render(Template.body, document.body, comment);
-          Template.body.view = newView;
-        } else if (view.dataVar) {
-          Blaze.renderWithData(renderFunc, view.dataVar.curValue?.value, parentEl, comment);
+        let comment;
+        if (view._hmrAfter) {
+          comment = view._hmrAfter;
         } else {
-          Blaze.render(renderFunc, parentEl, comment);
+          const first = view._domrange.firstNode();
+          comment = document.createComment('Blaze HMR PLaceholder');
+          parentEl.insertBefore(comment, first);
+        }
+
+        view._hmrAfter = null;
+        view._hmrParent = null;
+
+        if (view._domrange) {
+          Blaze.remove(view);
         }
 
-        parentEl.removeChild(comment);
-      } catch (e) {
-        console.log('[Blaze HMR] Error re-rending template:');
-        console.error(e);
-
-        // Record where the view should have been so we can still render it
-        // during the next update
-        const newestRoot = Blaze.__rootViews[Blaze.__rootViews.length - 1];
-        if (newestRoot && newestRoot.isCreated && !newestRoot.isRendered) {
-          newestRoot._hmrAfter = comment;
-          newestRoot._hmrParent = parentEl;
+        try {
+          if (view === Template.body.view) {
+            const newView = Blaze.render(Template.body, document.body, comment);
+            Template.body.view = newView;
+          } else if (view.dataVar) {
+            Blaze.renderWithData(renderFunc, view.dataVar.curValue?.value, parentEl, comment);
+          } else {
+            Blaze.render(renderFunc, parentEl, comment);
+          }
+
+          parentEl.removeChild(comment);
+        } catch (e) {
+          console.log('[Blaze HMR] Error re-rending template:');
+          console.error(e);
+
+          // Record where the view should have been so we can still render it
+          // during the next update
+          const newestRoot = Blaze.__rootViews[Blaze.__rootViews.length - 1];
+          if (newestRoot && newestRoot.isCreated && !newestRoot.isRendered) {
+            newestRoot._hmrAfter = comment;
+            newestRoot._hmrParent = parentEl;
+          }
         }
       }
-    }
-  });
-};
+    });
+  };
+
+} // end if (Meteor.isClient)
 
+// _migrateTemplate is called by compiled template code on both client and server.
+// On the server, it just registers the template without HMR logic.
 Template._migrateTemplate = function (templateName, newTemplate, migrate) {
-  const oldTemplate = Template[templateName];
-  migrate = Template.__pendingReplacement.includes(templateName);
-
-  if (oldTemplate && migrate) {
-    newTemplate.__helpers = oldTemplate.__helpers;
-    newTemplate.__eventMaps = oldTemplate.__eventMaps;
-    newTemplate._callbacks.created = oldTemplate._callbacks.created;
-    newTemplate._callbacks.rendered = oldTemplate._callbacks.rendered;
-    newTemplate._callbacks.destroyed = oldTemplate._callbacks.destroyed;
-    delete Template[templateName];
-    Template._applyHmrChanges(templateName);
-  }
+  if (Meteor.isClient) {
+    const oldTemplate = Template[templateName];
+    migrate = Template.__pendingReplacement.includes(templateName);
+
+    if (oldTemplate && migrate) {
+      newTemplate.__helpers = oldTemplate.__helpers;
+      newTemplate.__eventMaps = oldTemplate.__eventMaps;
+      newTemplate._callbacks.created = oldTemplate._callbacks.created;
+      newTemplate._callbacks.rendered = oldTemplate._callbacks.rendered;
+      newTemplate._callbacks.destroyed = oldTemplate._callbacks.destroyed;
+      delete Template[templateName];
+      Template._applyHmrChanges(templateName);
+    }
 
-  if (migrate) {
-    Template.__pendingReplacement.splice(
-      Template.__pendingReplacement.indexOf(templateName),
-      1
-    )
+    if (migrate) {
+      Template.__pendingReplacement.splice(
+        Template.__pendingReplacement.indexOf(templateName),
+        1
+      );
+    }
   }
 
   Template.__checkName(templateName);