jQueryUI multiple selection by default and have lasso toggle selected status

Question

I'm trying to implement a comparison chart-like table, and a large list of selectable objects would work just perfectly, save for a few functionality changes that I need. I see that both of these have been addressed in previous questions, but neither of them provide complete solutions.

This question addressed the multiple select behavior by default, but only says 'I did it on my own' without providing anything. Looking at the internals of selectable, I see that if I play with the !event.metaKey condition I could probably get the behavior I'm looking for without too much trouble, but was wondering if anyone had a solution that didn't involve editing the internals.

Similarly, this page addresses the lasso toggle effect that I desired, but I'm not sure where in the code the lasso functionality was changed and as the rest of the script (the sortable functionality) is reported to not work in chrome or IE8 (link) and is outdated as this point, I'd rather not rely on the entire thing.

So if anyone could help me out with either of these, I'd appreciate it. Thanks

[Edit] Formatting...

Answer 1

I'm sure there's a better way to do this, but here's what I've did within the selectable js file.

For the always multi-selection:

I added an option 'alwaysMulti' (default false). Then I replaced the three instances of !event.metaKey with (!event.metaKey && !options.alwaysMulti) and the two instances of event.metaKey with (event.metaKey || options.alwaysMulti).

To get the selection lasso to toggle the selected status, I found the changes I needed from the second page I linked to. I also added an option 'lassoToggle' (default false) to trigger this functionality. Within _mouseDrag, there is a condition if (hit), it gets changed to the following:

    if (hit) {
                // SELECT
                selectee.deselect = false;
                if (selectee.selected || (options.lassoToggle && (selectee.startselected && event.metaKey)) {
                    selectee.$element.removeClass('ui-selected');
                    selectee.selected = false;
                    selectee.deselect = true;
                }
                if (selectee.unselecting) {
                    selectee.$element.removeClass('ui-unselecting');
                    selectee.unselecting = false;
                }
                if (!selectee.selecting && (!options.lassoToggle || !selectee.deselect) {
                    selectee.$element.addClass('ui-selecting');
                    selectee.selecting = true;
                    // selectable SELECTING callback
                    self._trigger("selecting", event, {
                        selecting: selectee.element
                    });
                }
                if(selectee.deselect && options.lassoToggle) {
                    selectee.$element.removeClass('ui-selecting');
                    selectee.selecting = false;
                    selectee.$element.addClass('ui-unselecting');
                    selectee.unselecting = true;
                    // selectable UNSELECTING callback
                    self._trigger("unselecting", event, {
                        unselecting: selectee.element
                    });
                }
            }

Note: The event.metaKey change for the multi-select isn't in that code sample.

Hopefully this helps someone else!