Dear Both,
Thanks a lot for your time.
I have been away for a couple of weeks and did not have the time to
follow up until today.
I'll have a serious look at your info and will let you know if I
manage to crack this nut.
Thanks again
-R
On Sep 15, 2:29 am, John McLaughlin <johnmclaugh...@massanimation.com>
wrote:
> @Robert. Right you are. I checked the docs and db.get is a magic get
> anything function. Sorry for the noise.
>
> So I'm going for door #2 now. In ServePhoto "photo" must be the
> correctly returned key. Otherwise accessing "photo.photo" would give
> an error. So photo.photo must truly be a false value. This means to
> me that although "photo" is a valid object, the photo.photo property
> never got set properly. This takes us back to "UploadPhoto". It's
> unlikely that photo.put() failed. And it's likely that "db.Blob"
> created a valid db.Blob object. However accessing "photo.photo"
> doesn't return the db.Blob object, but rather the underlying data that
> came into it. Therefore I think your original hunch that the incoming
> data for db.Blob is an empty string is correct. I've struggled with
> multi-part posts so I'm not 100% sure about the html. One thing that
> looks suspicious is the hard coding of the hostname:port in the post
> action. Are you sure you don't want simply "/uploadphoto"? That
> could send the uploads to the wrong place, for example different ports
> use different datastores on the Dev Server.
>
> On Sep 14, 9:17 am, Robert Kluin <robert.kl...@gmail.com> wrote:
>
>
>
> > db.get() will grab an entity of _any_ kind. Model.get checks that the
> > key is for the correct kind of entity before fetching it. Either will
> > work. When I use db.get I usually include a check to make sure the
> > keys are the correct kind.
>
> > The key he posted in his initial thread is a Photo.
>
> > Robert
>
> > On Tue, Sep 14, 2010 at 11:34, John McLaughlin
>
> > <johnmclaugh...@massanimation.com> wrote:
> > > The one thing that looked off to me is that the line in ServePhoto
>
> > > photo = db.get(self.request.get("photo_id"))
>
> > > might want to be
>
> > > photo = Photo.get(self.request.get("photo_id"))
>
> > > I think db.get is a datastore method, not an inherited method from
> > > db.Model
>
> > > On Sep 13, 8:09 pm, Robert Kluin <robert.kl...@gmail.com> wrote:
> > >> I glanced over your code, nothing really major jumped out at me. If
> > >> you are not getting an exception in ServePhoto then the model is
> > >> clearly getting created and successfully fetched.
>
> > >> So, here are my first thoughts:
> > >> Have you tried logging some debug info in the UploadPhoto and
> > >> ServePhoto handlers? Specifically are you sure data is actually in
> > >> the photo property and it is not just an empty string or something?
> > >> Maybe you could try logging len(photo.photo) right before saving it,
> > >> then again right after fetching it.
>
> > >> What happens when you remove the if and simply return photo.photo?
>
> > >> Robert
>
> > >> class ServePhoto (webapp.RequestHandler):
> > >> def get(self):
> > >> photo = db.get(self.request.get("photo_id"))
> > >> if photo.photo:
> > >> self.response.headers['Content-Type'] = "image/jpg"
> > >> self.response.out.write(photo.photo)
> > >> else:
> > >> self.error(404)
>
> > >> ------
> > >> Robert Kluin
> > >> Ezox Systems, LLC
>
> > >> On Sun, Sep 12, 2010 at 22:03, Raymond
>
> > >> <raymond.othenin-gir...@raydropin.com> wrote:
> > >> > Hi All,
>
> > >> > I have been trying to understand how to upload and download images
> > >> > from to a Blobstore and have hit a wall.
> > >> > I have essentially made a modified version of the Guestbook example
> > >> > provided by google and modified it to suit my needs, I have tested the
> > >> > guestbook app as is and got it working, somehow somewhere I am making
> > >> > a simple mistake that frustrate every attempt at getting it working in
> > >> > my own code.
> > >> > I have stripped down my code to the essential in the hope of
> > >> > understanding what is wrong, but I am still stuck.
>
> > >> > What am I attempting to do ?
> > >> > Upload in a blobstore an image and display it in a web page.
>
> > >> > What is my code ?
>
> > >> > 1) My upload form served from a static page
>
> > >> > ...
> > >> > <form action="http://192.168.0.196:8083/uploadphoto";
> > >> > enctype="multipart/form-data" method="post">
> > >> > <div><label>Attempt at uploading a picture using a
> > >> > form</label></
> > >> > deiv>
> > >> > <div><input type="file" name="photo" /></div>
> > >> > <div><input type="submit" value="Upload Photo" /></div>
> > >> > </form>
> > >> > ...
>
> > >> > 2) My db model :
>
> > >> > class Photo(db.Model):
> > >> > photo = db.BlobProperty()
> > >> > date = db.DateTimeProperty(auto_now_add=True)
>
> > >> > 3) The code uploading the photo and saving it in the blobstore
>
> > >> > class UploadPhoto(webapp.RequestHandler):
> > >> > def post(self):
> > >> > photo = Photo()
> > >> > img = self.request.get('photo')
> > >> > photo.photo = db.Blob(img)
> > >> > photo.put()
>
> > >> > 4) The code creating the web page displaying the images :
>
> > >> > class PhotoPage(webapp.RequestHandler):
> > >> > def get(self):
> > >> > self.response.out.write('<html><pre>')
> > >> > self.response.out.write('<h1>Date&Time Photo</h1>')
> > >> > photos = db.GqlQuery("SELECT * FROM Photo ORDER BY date
> > >> > DESC LIMIT
> > >> > 10")
> > >> > for photo in photos:
> > >> > self.response.out.write('<p>%s ' % photo.date)
> > >> > self.response.out.write('<img
> > >> > src="servephoto?photo_id=%s" /></p>'
> > >> > % photo.key())
> > >> > self.response.out.write('</pre></body></html>')
>
> > >> > 5) The code serving the images :
>
> > >> > class ServePhoto (webapp.RequestHandler):
> > >> > def get(self):
> > >> > photo = db.get(self.request.get("photo_id"))
> > >> > if photo.photo:
> > >> > self.response.headers['Content-Type'] = "image/jpg"
> > >> > self.response.out.write(photo.photo)
> > >> > else:
> > >> > self.error(404)
>
> > >> > Everything seem to work until this last stage, I can select an image
> > >> > in my form, upload it, Something is written in Binary in the
> > >> > Blobstore.
> > >> > When I visit the page supposed to display the image I see all info but
> > >> > a broken image icon.
> > >> > I checked the source code and the HTML seem to be just fine, here it
> > >> > is with one record in the blobstore, I get the blob key which mena
> > >> > that there is a record with some binary stuff in it.
>
> > >> > <html><pre><h1>Date&Time Photo</h1><p>2010-09-13
> > >> > 00:31:14.477698 <img
> > >> > src="servephoto?photo_id=agt0ZXN0cmF5c3Bvc3ILCxIFUGhvdG8YWww" /></p></
> > >> > pre></body></html>
>
> > >> > I also know that the ServePhoto class is called and executed but it if
> > >> > photo.photo always return false and execute self-eror(404).
> > >> > I tried replacing this with a different error code and it always
> > >> > display the error code so I am sure the if statement get a false.
>
> > >> > My questions is, why would the if statement get a false if there is
> > >> > effectively an image in the blobstore (Proved by the fact that I can
> > >> > retrieve it's key) ?
>
> > >> > I am sorry for the long post, and hope I am not too confusing.
>
> > >> > Thanks for any hint that would get me on the right way and forgive me
> > >> > if the answer is obvious, I probably need new eyes.
>
> > >> > Raymond
>
> > >> > --
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>
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