how to load all image from google app engine data store?

Question

my code is below. it loads only the first image form 'posts' database. how can i load the all image from the database????

import webapp2
import os
import jinja2
from google.appengine.ext import db
from google.appengine.api import images

jinja template code

template_dir = os.path.join(os.path.dirname(__file__), 'templates')
jinja_env = jinja2.Environment(loader = jinja2.FileSystemLoader(template_dir),
                           autoescape = True)

class Handler(webapp2.RequestHandler):
    def write(self, *a, **kw):
        self.response.out.write(*a, **kw)

    def render_str(self, template, **params):
        t = jinja_env.get_template(template)
        return t.render(params)

    def render(self, template, **kw):
        self.write(self.render_str(template, **kw))

html for image upload

form="""
<form action="/" enctype="multipart/form-data" method="post">
          <div><label>Avatar:</label></div>
          <div><input type="file" name="img"/></div>
          <input type="submit" value="switch">
          </form>
"""

database for image

class Greeting(db.Model):
    avatar = db.BlobProperty() 
    created = db.DateTimeProperty(auto_now_add = True)

this is for image. but it loads only the first image form 'posts' database. how can i load the all image from the database?

class Image(Handler):
    def get(self):
        posts = db.GqlQuery("select * from Greeting order by created desc")
        for post in posts:

            self.response.headers['Content-Type'] = 'image/jpg'
            self.response.out.write(post.avatar)

MainHandler and resize the image

class MainHandler(Handler):
    def get(self):
        self.response.out.write(form)
    def post(self):
        avatar = images.resize(self.request.get('img'), 400, 400)
        greeting = Greeting()
        greeting.avatar = db.Blob(avatar)
        greeting.put()    


app = webapp2.WSGIApplication([('/', MainHandler),
                               ('/img', Image),],
                               debug=True)

Answer 1

Rather than iterating through posts ( for post in posts ) when the handler calls Image do it via your jinja2 template. Pass posts to your template using self.response.out.write(posts) .

jinja2 template:

{% for post in posts %}
    {{post}}
{% endfor %}