Introducing template-tag feature flag

app/controllers/application.js

@@ -0,0 +1,5 @@
+import GuideMakerApp from 'guidemaker/controllers/application';
+
+export default class ApplicationController extends GuideMakerApp {
+  queryParams = ['feature_flags']
+}

app/routes/application.js

@@ -0,0 +1,17 @@
+import GuideMakerApp from 'guidemaker/routes/application';
+import { service } from '@ember/service';
+
+const FEATURES = {
+  'template-tag': false,
+};
+
+export default class ApplicationRoute extends GuideMakerApp {
+  @service features;
+
+  model(params, ...rest) {
+    let { feature_flags } = params;
+    let overrides = Object.fromEntries(feature_flags?.split(',').map(flag => [flag, true]) ?? []);
+    this.features.setupFeatures(Object.assign({}, FEATURES, overrides));
+    return super.model(params, ...rest);
+  }
+}

config/environment.js

@@ -5,7 +5,10 @@ module.exports = function (environment) {
     modulePrefix: 'ember-guides',
     environment,
     rootURL: '/',
-    locationType: 'trailing-history',
+
+    // TODO: fix trailing-history to support query params
+    locationType: 'history',
+
     historySupportMiddleware: true,
 
     EmberENV: {

guides/release/getting-started/quick-start.md

@@ -83,6 +83,22 @@ Congratulations! You just created and booted your first Ember app.
 
 ## Write some HTML in a template
 
+<feature-flag-on-template-tag>
+
+We will start by editing the `application` template.
+This template is always on screen while the user has your application loaded.
+In your editor, open `app/templates/application.gjs` and change it to the following:
+
+```gjs {data-filename=app/templates/application.gjs}
+<template>
+  <h1>PeopleTracker</h1>
+  {{outlet}}
+</template>
+```
+</feature-flag-on-template-tag>
+
+<feature-flag-off-template-tag>
+
 We will start by editing the `application` template.
 This template is always on screen while the user has your application loaded.
 In your editor, open `app/templates/application.hbs` and change it to the following:
@@ -93,6 +109,8 @@ In your editor, open `app/templates/application.hbs` and change it to the follow
 {{outlet}}
 ```
 
+</feature-flag-off-template-tag>
+
 Ember detects the changed file and automatically reloads the page for you in the background.
 You should see that the welcome page has been replaced by "PeopleTracker".
 You also added an `{{outlet}}` to this page,

package.json

@@ -86,7 +86,7 @@
     "eslint-plugin-qunit": "^7.2.0",
     "gfm-code-blocks": "^1.0.0",
     "guidemaker": "^4.0.3",
-    "guidemaker-ember-template": "^4.0.1",
+    "guidemaker-ember-template": "^4.1.0",
     "loader.js": "^4.7.0",
     "lodash": "^4.17.21",
     "markdown-link-extractor": "1.2.3",