Facebook SDK failed to generate preview for user only when opengraphobject.setproperty("og:url") is set

Question 1

If you don't have a web component, then do not set a url in the og object. If you set a url, facebook will try to go scrape that url, and if the OG metadata scraped from there doesn't match what you've provided, then it will fail.

If you want to add a bitmap to your OG action, in addition to what you're currently doing, you must also add a NativeAppCallContentProvider to your manifest. See the docs here: https://developers.facebook.com/docs/reference/android/current/class/NativeAppCallContentProvider/ This is how the Facebook app can actually get the bitmaps you're trying to send.

Lastly, have a look at the Scrumptious sample app that ships with the sdk. It has an option (if you "skip login") that creates a new OG object, with an image attachment.

Question 2

With this code it works and I don't have "Failed to generate preview". But this code is working something different that I want. This code open a OGActiondialog but when I share it the post never appear in the feed and appear in the activity registry but only appear the photo, not the name or description like a "normal" sharelink (small photo to the left and titol and description to the right).

Is it possible to do this?

private void OpenShareDialog2(){

    if (canPresentOGShareDialog) {
        Session session = Session.getActiveSession();

        if (session != null) {
            // Check for publish permissions
            List<String> permissions = session.getPermissions();
            if (!isSubsetOf(PERMISSIONS, permissions)) {
                pendingPublishReauthorization = true;
                Session.NewPermissionsRequest newPermissionsRequest = new Session.NewPermissionsRequest(this, PERMISSIONS);
                session.requestNewPublishPermissions(newPermissionsRequest);
                Log.d(TAG, "Permisos pedidos");
                return;
            }

        }

        OpenGraphObject oplugar = OpenGraphObject.Factory.createForPost("namespace:lugar");
        oplugar.setProperty("og:type","namespace:lugar");
        oplugar.setProperty("og:title", LugarCargado.getNombre());
        oplugar.setProperty("og:description", LugarCargado.getDescripcion());



        //OpenGraphAction action = GraphObject.Factory.create(OpenGraphAction.class);
        OpenGraphAction action = OpenGraphAction.Factory.createForPost("namespace:publicar");
        action.setProperty("lugar", oplugar);
        action.setType("namespace:publicar");
        //action.setProperty("previewPropertyName", "lugar");
        //action.setProperty("fb:explicitly_shared", true);
        //action.setExplicitlyShared(true);

        boolean userGenerated = false;
        if (urifoto != null) {
            String photoUriString = urifoto.toString();
            Pair<File, Integer> fileAndMinDimemsion = getImageFileAndMinDimension();
            userGenerated = fileAndMinDimemsion.second >= USER_GENERATED_MIN_SIZE;

            // If we have a content: URI, we can just use that URI, otherwise we'll need to add it as an attachment.
            if (fileAndMinDimemsion != null && urifoto.getScheme().startsWith("content")) {
                action.setImage(getImageListForAction(photoUriString, userGenerated));
            }
        }

        FacebookDialog.OpenGraphActionDialogBuilder builder = new FacebookDialog.OpenGraphActionDialogBuilder(this, action, "lugar");
                //.setFragment(SelectionFragment.this);

        if (urifoto != null && !urifoto.getScheme().startsWith("content")) {
            builder.setImageAttachmentFilesForAction(Arrays.asList(new File(urifoto.getPath())), userGenerated);
        }

        uiHelper.trackPendingDialogCall(builder.build().present()); 
    }
}

private Pair<File, Integer> getImageFileAndMinDimension() {
    File photoFile = null;
    String photoUriString = urifoto.toString();
    if (photoUriString.startsWith("file://")) {
        photoFile = new File(urifoto.getPath());
    } else if (photoUriString.startsWith("content://")) {
        String [] filePath = { MediaStore.Images.Media.DATA };
        Cursor cursor = this.getContentResolver().query(urifoto, filePath, null, null, null);
        if (cursor != null) {
            cursor.moveToFirst();
            int columnIndex = cursor.getColumnIndex(filePath[0]);
            String filename = cursor.getString(columnIndex);
            cursor.close();

            photoFile = new File(filename);
        }
    }

    if (photoFile != null) {
        InputStream is = null;
        try {
            is = new FileInputStream(photoFile);

            // We only want to get the bounds of the image, rather than load the whole thing.
            BitmapFactory.Options options = new BitmapFactory.Options();
            options.inJustDecodeBounds = true;
            BitmapFactory.decodeStream(is, null, options);

            return new Pair<File, Integer>(photoFile, Math.min(options.outWidth, options.outHeight));
        } catch (Exception e) {
            return null;
        } finally {
            Utility.closeQuietly(is);
        }
    }
    return null;
}

I get it more or less from scrumptious sample!