Add support for twitter cards (full image viewer only)

[manics]

I've had this lurking around since January 2014. Given that we now have a public resource and Twitter no longer require manual approvals I thought it's time to resurrect it. See https://dev.twitter.com/cards/types/summary-large-image

The title and description fields are mandatory, I'm assuming there will always be a non-empty image name, description is set to the owner's name if empty.

At risk of stating the obvious this can only be tested with a public image on an external server. Open an image in the full image viewer, copy the url into a tweet.

[joshmoore]

Does configuration need to be per server_list item?

[manics]

Good point. I guess one option is

omero.web.twitter = {
    "<key>": {
        "enabled": true,
        "siteuser": "@openmicroscopy"
    }
}

with a key from omero.web.application_server.host- assuming its possible to obtain which host was selected.

[manics]

The enabled key seemed redundant, so now it's just a dictionary of server-names to twitter-names, e.g. omero.web.sharing.twitter={"omero": "@openmicroscopy"}

[manics]

Ideally this would be testable without deploying it live to the IDR.

[manics]

Also added opengraph (facebook) support

[joshmoore]

Interesting (unrelated) travis failure:

package:
      [jar] error while reading original manifest in file: /home/travis/build/openmicroscopy/openmicroscopy/components/tools/OmeroJava/target/omero_client.jar due to error in opening zip file
BUILD FAILED
/home/travis/build/openmicroscopy/openmicroscopy/build.xml:179: The following error occurred while executing this line:
/home/travis/build/openmicroscopy/openmicroscopy/components/antlib/resources/global.xml:449: The following error occurred while executing this line:
/home/travis/build/openmicroscopy/openmicroscopy/components/tools/OmeroJava/build.xml:90: Problem reading /home/travis/build/openmicroscopy/openmicroscopy/components/tools/OmeroJava/target/omero_client.jar

Relaunched.

[manics]

Example config

config set omero.web.server_list '[["demo.example.org",4064,"demotwitter"]]'
config set omero.web.sharing.twitter '{"demotwitter": "@openmicroscopy"}'
config set omero.web.sharing.opengraph '{"demotwitter": "Open Microscopy"}'

[manics]

In theory the last line should set the name of the site shown in facebook, though it doesn't seem to.

[joshmoore]

This is currently leading to:

Traceback (most recent call last):
  File "manage.py", line 38, in <module>
    import settings
  File "/home/omero/OMERO.server-5.1.4-232-1ff6fcd-ice35-b170/lib/python/omeroweb/settings.py", line 781, in <module>
    'DEPRECATED_SETTINGS_MAPPINGS')
  File "/home/omero/OMERO.server-5.1.4-232-1ff6fcd-ice35-b170/lib/python/omeroweb/settings.py", line 772, in process_custom_settings
    setattr(module, global_name, mapping(global_value))
  File "/opt/anaconda/lib/python2.7/json/__init__.py", line 338, in loads
    return _default_decoder.decode(s)
  File "/opt/anaconda/lib/python2.7/json/decoder.py", line 366, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())

[manics]

@joshmoore I think the last build you deployed was missing the last commit 7845fd6 which should've fixed that error.

[manics]

--rebased-to #4613