Add ability to serve JSON, also added a small example HTML page to il…

…lustrate how to use it.
pmoor · Mar 12, 2011 · 96bd8f4 · 96bd8f4
1 parent 950bbe6
commit 96bd8f4
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Showing 5 changed files with 164 additions and 28 deletions.
diff --git a/app.yaml b/app.yaml
@@ -21,7 +21,10 @@ api_version: 1
 
 handlers:
 - url: /user/([^/]+)
-  script: user.py
+  script: main.py
+
+- url: /json/([^/]+)
+  script: main.py
 
 - url: /
   script: root.py
@@ -37,3 +40,4 @@ skip_files:
 - ^(.*/)?.*/RCS/.*
 - ^(.*/)?\..*
 - ^google_appengine$
+- ^examples$
diff --git a/examples/slideshow.html b/examples/slideshow.html
@@ -0,0 +1,62 @@
+<!--
+ rndpic - an App Engine app to display random pictures from Picasa Web.
+ Copyright (C) 2011 Patrick Moor <patrick@moor.ws>
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program.  If not, see <http://www.gnu.org/licenses/>.
+-->
+<html>
+<head>
+<title>sample slideshow using rndpic.appspot.com</title>
+</head>
+<body>
+<p>This is a sample slideshow using <a href="http://rndpic.appspot.com">rndpic.appspot.com</a>.</p>
+<div>
+<a href="#" id="rndpic_link"><img id="rndpic_image"/></a>
+</div>
+
+<script type="text/javascript">
+
+function loadNewImage() {
+  xmlhttp = new XMLHttpRequest();
+  xmlhttp.onreadystatechange = function() {
+    if (xmlhttp.readyState == 4) {
+      var image = eval("(" + xmlhttp.responseText + ")");
+
+      function switchImage() {
+        var linkTag = document.getElementById("rndpic_link");
+        var imageTag = document.getElementById("rndpic_image");
+        linkTag.href = image.target_url;
+        imageTag.width = image.width;
+        imageTag.height = image.height;
+        imageTag.src = image.thumbnail_url;
+      }
+
+      var preloadedThumbnail = new Image();
+      preloadedThumbnail.src = image.thumbnail_url;
+      preloadedThumbnail.onload = switchImage
+
+      // reload every 5 seconds
+      window.setTimeout("loadNewImage()", 5 * 1000);
+    }
+  };
+  xmlhttp.open("GET", "http://rndpic.appspot.com/json/patrick.moor?size=400u", true);
+  xmlhttp.send();
+}
+
+loadNewImage();
+
+</script>
+
+</body>
+</html>
diff --git a/json_handler.py b/json_handler.py
@@ -0,0 +1,39 @@
+# rndpic - an App Engine app to display random pictures from Picasa Web.
+# Copyright (C) 2011 Patrick Moor <patrick@moor.ws>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from google.appengine.ext import webapp
+from django.utils import simplejson 
+
+class JsonHandler(webapp.RequestHandler):
+
+  def __init__(self, picker):
+    self._picker = picker
+
+  def get(self, user_name):
+    self.response.headers["Content-Type"] = "application/json"
+    self.response.headers["Access-Control-Allow-Origin"] = "*"
+    size = self.request.get("size", "200u")
+    picture = self._picker.Pick(user_name, size)
+    if picture:
+      content = {
+        "height": picture.GetHeight(),
+        "width": picture.GetWidth(),
+        "thumbnail_url": picture.GetThumbnailUrl(),
+        "target_url": picture.GetLink(),
+      }
+      simplejson.dump(content, self.response.out)
+    else:
+      self.response.set_status(204)
diff --git a/main.py b/main.py
@@ -0,0 +1,53 @@
+# rndpic - an App Engine app to display random pictures from Picasa Web.
+# Copyright (C) 2011 Patrick Moor <patrick@moor.ws>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from google.appengine.ext import webapp
+from google.appengine.ext.webapp.util import run_wsgi_app
+
+from feed import FeedRepository
+from album_repository import AlbumRepository
+from picker import RandomPicturePicker
+
+from user_handler import UserHandler
+from json_handler import JsonHandler
+
+
+repository = AlbumRepository(FeedRepository())
+picker = RandomPicturePicker(repository)
+
+
+def _ConstructUserHandler():
+  return UserHandler(picker)
+
+
+def _ConstructJsonHandler():
+  return JsonHandler(picker)
+
+
+application = webapp.WSGIApplication(
+    [
+      (r'/user/([^/]+)', _ConstructUserHandler),
+      (r'/json/([^/]+)', _ConstructJsonHandler),
+    ],
+    debug=False)
+
+
+def main():
+  run_wsgi_app(application)
+
+
+if __name__ == "__main__":
+  main()
diff --git a/user.py → user_handler.py b/user.py → user_handler.py
@@ -1,5 +1,5 @@
 # rndpic - an App Engine app to display random pictures from Picasa Web.
-# Copyright (C) 2010 Patrick Moor <patrick@moor.ws>
+# Copyright (C) 2011 Patrick Moor <patrick@moor.ws>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -15,23 +15,16 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from google.appengine.ext import webapp
-from google.appengine.ext.webapp.util import run_wsgi_app
-
-from feed import FeedRepository
-from album_repository import AlbumRepository
-from picker import RandomPicturePicker
-
-
-repository = AlbumRepository(FeedRepository())
-picker = RandomPicturePicker(repository)
-
 
 class UserHandler(webapp.RequestHandler):
 
+  def __init__(self, picker):
+    self._picker = picker
+
   def get(self, user_name):
     size = self.request.get("size", "200u")
     link = bool(int(self.request.get("link", 1)))
-    picture = picker.Pick(user_name, size)
+    picture = self._picker.Pick(user_name, size)
     if picture:
       html = """<img src="%s" width="%d" height="%d" id="rndpic-img"/>""" % (
           picture.GetThumbnailUrl(),
@@ -45,18 +38,3 @@ def get(self, user_name):
       self.response.out.write("document.write('%s');" % html)
     else:
       self.response.set_status(204)
-
-
-
-
-application = webapp.WSGIApplication(
-    [(r'/user/([^/]+)', UserHandler)],
-    debug=False)
-
-
-def main():
-  run_wsgi_app(application)
-
-
-if __name__ == "__main__":
-  main()