This should be toggleable with a setting. Also this will conflict with #4807 (but I guess I'll have to take care of that)

What should the name of the setting be? hideSingleColumnSortIndicator?

I'm still having a hard time seeing why anyone would turn this off. Are there any other examples of grids that show numeric sort indicators like this when only one column is sorted?

@JLLeitschuh I agree with the comment above. Is there a reason we need to always show a sort indicator of 1 if there is only one column sorted?

So does someone need to make a decision?

I like this idea. If more than 1 sort is provided, add numbers, (indexing at 1) otherwise do not show priority

Okay, this makes sense. I see no problem with merging this.

There is something off with this solution. I just pulled 3.1.0 down to test this.

1. I sort on 1 column --> I get an arrow indicator with no priority number shown (GOOD)
2. I sort on a 2nd column --> First sort remains with same indicator, new column gets an arrow indicatory (BAD) ==> expected result: once I sort on a 2nd column I should see a "1" next to my first column and a "2" next to my second
3. I sort on a 3rd column --> First column remains with no priority indicator, second column gets a "1" indicator, and 3rd column gets a "2" indicator (BAD) ===> expected result: I should see sort priorities "1", "2", "3"

The reason this is not working properly is because in ui-grid-header-cell.js you are testing for:

$scope.grid.columns.some(function(element, index){
                  return element.sort.priority !== undefined && element !== $scope.col;
                });

but if element.sort.priority === 0 then this condition is returning 0 which will result with isSortPriorityVisible resolving as 0 or "false" when it should be "true"

@JLLeitschuh where is your fix to index sort.priority at 1 instead of 0? If this went in, then the condition above would resolve to true and there would be no bug