Dynamically-generated manifests.

app.yaml

@@ -12,6 +12,10 @@ handlers:
   http_headers:
     X-Content-Type-Options: nosniff
 
+- url: /manifest.json
+  script: manifest.app
+  secure: always
+
 - url: /baby/.*
   static_files: static/babystats.html
   upload: static/babystats.html

manifest.py

@@ -0,0 +1,23 @@
+import json
+import webapp2
+
+
+class Manifest(webapp2.RequestHandler):
+
+  def get(self):
+    self.response.headers['Content-Type'] = 'application/json'
+    json.dump({
+        'name': self.request.get('name'),
+        'display': 'standalone',
+        'icons': [
+            {
+                'src': '/static/icon.png',
+                'sizes': '256x256',
+            },
+        ],
+    }, self.response.out)
+
+
+app = webapp2.WSGIApplication([
+  ('/manifest.json', Manifest),
+])

static/babystats.js

@@ -147,6 +147,10 @@ BabyStats.prototype.checkInit_ = function() {
     return;
   }
 
+  this.manifest_ = document.createElement('link');
+  this.manifest_.rel = 'manifest';
+  document.head.appendChild(this.manifest_);
+
   this.buildCells_();
   this.buildLayout_();
 
@@ -251,6 +255,8 @@ BabyStats.prototype.handleMessage_ = function(isEvent, message) {
       }
       document.title = message.message.child_name;
       this.displayChildName_.textContent = message.message.child_name;
+      this.manifest_.href =
+          '/manifest.json?name=' + encodeURIComponent(this.childName_.value);
       break;
 
     default: