Idea #2992
Updated by Tom Clegg almost 9 years ago
h3. background Pipeline components are stored in a hash. In Ruby, and in the YAML representation of components that is stored in the database, the ordering of hash keys is consistent. However, when the components are handled by other languages such as Python (for example, by arv-copy) the order of components is likely to get permuted because key order is generally not predictable guaranteed by json or for "dict" or "hash" types by the in hash/dictionary implementations. most languages. Pipeline template authors should be able An algorithm to control the display order (without relying on ordered dictionary implementations) by supplying a display_order key (with a numeric value) in each component. h3. solution / implementation Workbench should sort components by display_order when rendering pipeline templates and instances. * If no display_order is given, don't sort: assume the hash implementation provides the correct order (as it does now). API server, before saving a pipeline template, should: * Renumber the given display_order figures so they start at 1 and increase by 1. * Set max = number of components that had a display_order provided. * Iterate over all components (in whatever order is provided by the hash implementation, i.e., the order they appeared with consistent ordering was implemented way back in March in commit:ac2db7d4aa32a772d9f21db3f1a8a63b1ad0ca2f but reverted in April with commit:085e614c8e7d1a29e675cf839a1ce9d92ffc5d5c The topological/lexical sorting behavior should be restored. Users will retain the JSON document on the wire). Assign ++max ability to display_order for any component where it is missing. * Leave the components hash alone control sorting with a "display_order" field that, if it doesn't have the expected structure (e.g., it looks like @{"foo":[1,2,3]}@ and Workbench wouldn't be able to render it anyway). Older templates (if they are never updated) will still have undefined order if they end up getting copied/consumed by a Python program like arv-copy, etc. -- this is OK. Update fixtures and examples in docs to include display_order. present, takes precedence over default sorting.