transformations 6.x-1.0-alpha3

Last snapshot release for now, because I need to finish the "prose" part of my thesis now. (Development of Transformations will be continued in mid May, or something.) Of course, I'll still review and apply patches if any are contributed.

This release sports a number of important improvements, which, combined, make it possible to import data from CSV files to Drupal nodes without any use of PHP code. I need to write up a tutorial on how to do that, but it becomes more and more clear that the concept and architecture actually works pretty well, given the right set of operations.

Anyways, here's the bulk of what improved since the previous beta was released:

• The pipeline edit form now shows the actual set of operations as they appear in the pipeline - which means that the operation objects will know about their assigned input values and schemas, which in turn means that if the set of output slots depends on an input value then those will show up correctly and you can actually wire them up. (If that sounded too complicated, nevermind - just believe me that this is a good thing.)
• You can now assign result outputs of other pipelines to any operation inputs. This is specifically useful when you want to retrieve schemas in advance (e.g. in order to be able to map CSV columns to other operations). I'm sure there are other use cases as well, though.
• Two new operations: an "extract (first, second, ...) item from list" operation, and a simple mapping operation that exposes all items from a structure as operation outputs (with an association of input keys to output descriptions defining which keys can be mapped). Both are valuable to the mentioned CSV import use case.
• Usability improvements: operation and input/output slot descriptions are now shown as tooltips on the pipeline edit page, connected keys are highlighted on mouseover, and a couple more descriptions provided by included operations.
• Bug fixes all over the place, including in pipeline execution, pipeline editing and input data widgets.

Thanks to a gentle nudge of an interested observer (hi Mitchell!), I also created a number of tasks in the issue queue (also see here) in order to highlight upcoming tasks and provide direction for potential contributors. Issues are available in various flavors ranging from easy to difficult, so there should be something in there for everyone ;-)

Hopefully I'll be able to push Transformations further along soon. See you later!