Idea for ImageSelectionPlugin

Web based systems get more social. Images play an important role. TWiki's user homepages can be more usable and trendy if there is an easy way to manage profile pictures. Specific TWiki applications such as project trackers and team profile apps can be more fun with easily managed images.

An ImageSelectionPlugin can support that. I envision these high level features:

• handle images attached to a topic as a set
• pick an image from a list
• upload additional images
• on upload and on image selection:
  • convert the selected image to defined name(s) and size(s), and attach to topic

The last item is important. It allows one to show the active image easily. For example, a user might upload 5 images to the homepage. The plugin generates _image_selection_50x50.jpg and _image_selection_200x200.jpg attachments of the currently selected image. The underscore in the file name denotes a system generated attachment. In the profile header page, the image name can be assumed, e.g. the picture can be shown simply as:
<img src="%PUBURLPATH%/%USERSWEB%/%BASETOPIC%/_image_selection_200x200.jpg" width="200" height="200" alt='"" />

What is a good spec for the UI? For inspiration here is a screenshot of the profile picture selection of a commercial wiki vendor:

Ideas for implementation:

The ImageSelectionPlugin handles a %IMAGESELECTION{}% variable with these parameters:

• topic="Main.JohnSmith" - topic name that holds the images; defaults to current topic.
• generate="50x50, 150x, x200" - convert the image on image upload and image selection; defaults to IMAGESELECTIONPLUGIN_GENERATE setting.

The global IMAGESELECTIONPLUGIN_GENERATE setting defines the default set of images that are generated when an image is uploaded or selected. It is a comma-space separated list of WIDTHxHEIGHT, such as:

• 50x50 resizes the selected image to 50x50 and attaches it as _image_selection_50x50.jpg
• 150x resizes the selected image to 150 pixel width while retaining the aspect ratio, and attaches it as _image_selection_150x.jpg
• x200 resizes the selected image to 200 pixel height while retaining the aspect ratio, and attaches it as _image_selection_x200.jpg

A feature needs to be provided to bulk-convert images for a set of topics, for example when adding the plugin to an existing TWiki installation, and when changing the generate parameter.

-- Contributor: PeterThoeny - 2011-01-28

Feeback

An image selection plugin is useful for other sets of images besides profile pictures, such as header background image for skin, team picture in team homepages, project picture in project homepages etc.

-- PeterThoeny - 2011-02-24

This is now implemented in the core and the TWikiUserMappingContrib. See proposal with screenshots at MoreVisualUserHomepages.

I think there is still a need for a generic ImageSelectionPlugin, such as for team dashboards, project pages etc.

-- PeterThoeny - 2011-06-11