Must all data-tables kind of suck?

b8r's data-table in action
b8r now has a data-table component. It’s implemented in a little over 300loc, supports custom header and fixed headers, a correctly-positioned scrollbar, content cells, sorting, resizing, showing/hiding of columns.

Bindinator, up until a few weeks ago, did not have a data-table component. It has some table examples, but they’ve not seen much use in production because b8r is a rewrite of a rewrite of a library named bindomatic that I wrote for the USPTO that was implemented to do all the data-binding outside of data-tables in a large, complex project and then replaced all the data-tables.

It turns out that almost any complex table ends up being horrifically special-case and bindomatic, by being simpler, made it easier to build complex things bespoke. (I should note that I also wrote the original data-table component that bindomatic replaced.)

Ever since I first wrote a simple file-browser using b8r-native I’ve been wishing to make the list work as well as Finder’s windows. It would also benefit my RAW file manager if that ever turns into a real product.

The result is b8r’s data-table component, which is intended to scratch all my itches concerning data-tables (and tables in general) — e.g. fixed headers, resizable columns, showing/hiding columns, sorting, affording customization, etc. — while not being complex or bloated.

At a little over 300 loc I think I’ve avoided complexity and bloat, at any rate.

As it is, it can probably meet 80% of needs with trivial configuration (which columns do you want to display?), another 15% with complex customization. The remaining 5% — write your own!

Implementation Details

The cutest trick in the implementation is using a precisely scoped css-variable to control a css-grid to conform all the column contents to desired size. In order to change the entire table column layout, exactly one property of one DOM element gets changed. When you resize a column, it rewrites the css variable (if the number of rows is below a configurable threshold, it live updates the whole table, otherwise it only updates the header row until you’re done).

Another cute trick is to display the column borders (and the resizing affordance) using a pseudo-element that’s 100vh tall and clipped to the table component. (A similar trick could be used to hilite columns on mouse-over.)

Handling the actual drag-resizing of columns would be tricky, but I wrote b8r’s track-drag library some time ago to manage dragging once-and-for-all (it also deals with touch interfaces).

Next Steps…

There’s a to-do list in the documentation. None of it’s really a priority, although allowing columns to be reordered should be super easy and implementing virtualization should also be a breeze (I scratched that itch some time back).

The selection column shown in the animation is actually implemented using a custom headerCell and custom contentCell (there’s no selection support built in to data-table). I’ll probably improve the example and provide it as an helper library that provides a “custom column” for data-table and also serves as an example of adding custom functionality to the table.

I’d like to try out the new component with some hard-core use-cases, e.g. the example RAW file manager (which can easily generate lists of over 10,000 items), and the file-browser (I have an idea for a Spotlight-centric file browser), and — especially — my galaxy generator (since I have ideas for a web-based MMOG that will leverage the galaxy generator and use Google Firebase as its backend).