Openrefine: Add new text facet type

[ostephens]

Is your feature request related to a problem or area of OpenRefine? Please describe.
Add a new facet of type Text (as opposed to current "List" facet which is usually used for text values). This is in order to have a facet that facets on textual values while not attempting to automagically transform non-text value cells into text. The new Text facet should list all cell values that are text, and create buckets (with counts) for non-text values

Describe the solution you'd like

• [ ] Add support for a new facet type of "Text"
• [ ] Change option to "Create custom text facet" in menu to use this new facet (rather than the current use of List facet)
• [ ] Convert pre-defined facets to use new Text facet type where appropriate

Describe alternatives you've considered
See discussion in #1957 and #1662 and other linked PRs and issues

Additional context
See discussion in #1957 and #1662 and other linked PRs and issues

[ostephens]

Just to note progress. I didn't manage to get as much time as I hoped in the last week to look at this, but I did get some time to think through the problem. My plan currently is to:

• Create a new class for the current ListFacet behaviour which extends the ListFacet class
• Create a new class for a new text fact which extends the ListFacet class
• Shared code between these will continue to live in the ListFacet class. Where there are differences the new classes will override methods to implement the appropriate behaviour

I may do some further refactoring of the ListFacet class once I've done this initial work, but it is this initial work that needs to be completed to get us to a point where we have the current List Facet behaviour and the new Text Facet behaviour supported with a reasonably minimum amount of code duplication.

[ostephens]

In terms of actual progress I've written some extended tests for the current List Facet behaviour to make sure this continues to work in the current way

[wetneb]

@ostephens what is your timeline for this? Is your current work pushed on some branch? If so maybe I can help?

[ostephens]

@wetneb I've got time to look at this over this weekend - If I don't get the work completed, I'll share a branch with what I've done so we can share the work

[wetneb]

Feel free to share your branch if you need a hand on this :)

[ostephens]

Hi @wetneb - sorry I've been so slow on this.

You can see the progress (or lack of) I've made so far at https://github.com/ostephens/OpenRefine/tree/list-facet-refactor

I think the following commits are good & sensible steps:
https://github.com/ostephens/OpenRefine/commit/02501db87f21e2094cfa62f903b0bc02c0fe3e09
https://github.com/ostephens/OpenRefine/commit/4ce6769fc5a52fcb6263742fe2c9b384bf040e68

But apart from that I seem to end up going in circles. My original idea was to have an abstract class for a 'list facet' which would support grouping by any of the supported data types then be implemented by different types of list facet including the existing 'list facet' and a new 'text list facet' which would exhibit the new desired behaviour. But each time I look at this I start to think the whole way facets are structured feels not quite right, and end up fluctuating between just doing something v simple but duplicating loads of code, and revisiting the whole structure of the facet code (at which point I have to lie down in a dark room for half an hour).

So - sorry I've not really made progress with this and holding back 3.2 :(

[ostephens]

btw code as committed to this branch fails as follows:

[ERROR] Failures:
[ERROR]   TextListFacetTests.testBooleanSelection:340 NullPointer
[ERROR]   TextListFacetTests.testDateSelection:214 NullPointer
[ERROR]   TextListFacetTests.testIntegerSelection:277 NullPointer
[INFO]
[ERROR] Tests run: 597, Failures: 3, Errors: 0, Skipped: 0