Sortable plugin can break the query builder

[chriskr]

Issue is reproducible with examples/index.html of the repo. Create two rules, drag the first one and drop it when it overlaps the placeholder and the other rule to more or less the same degree. The drag target disappears and adding new rules no longer works.

The issue seems to be here

jQuery-QueryBuilder/src/core.js

Lines 254 to 264 in 7f25bb0

	'move': function(e, node, group, index) {
	node.$el.detach();
	if (index === 0) {
	node.$el.prependTo(group.$el.find('>' + QueryBuilder.selectors.rules_list));
	}
	else {
	node.$el.insertAfter(group.rules[index - 1].$el);
	}
	self.refreshGroupsConditions();
	},

. If group.rules[index - 1].$el is the node itself then insertAfter does obviously nothing. Suggested fix would be to add

if (index > 0 && node === group.rules[index - 1]) {
    return;
}

If that is ok I can make an according fix.

[chriskr]

The issue interact. Drag and drop works fine on http://querybuilder.js.org/demo.html#plugins. This uses interact.js v1.2.6 while the local dev version installs the newest interact.js v1.3.3. The difference is the order of event dispatch, v1.2.6 fires the drag end event after the drop event while v1.3.3 fires the end event before the drop. This removes the placeholder in the model before the rule is moved to the target position, in the worst case causing the rule to disappear and breaking the query builder.

Relevant code in the plugin

jQuery-QueryBuilder/src/plugins/sortable/plugin.js

Lines 76 to 83 in 7f25bb0

	onend: function() {
	// remove ghost
	ghost.remove();
	ghost = undefined;
	// remove placeholder
	placeholder.drop();
	placeholder = undefined;

and

jQuery-QueryBuilder/src/plugins/sortable/plugin.js

Lines 109 to 111 in 7f25bb0

	ondrop: function(event) {
	moveSortableToTarget(src, $(event.target), self);
	}