Hide filter prevents value from being used in chart

[brutaldev]

When hiding a column in the table using a "hide" filter, the value cannot be used as a column in the "columns" array of a chart header. This is contrary to the documentation that states "The Hide filter removes a column from a report. This is useful if you want to use a column in a chart, but don't want it actually appearing in the report."

Example:

-- Chart and Hide filter bug
-- Show that the hide filter (http://jdorn.github.io/php-reports/#HideFilter) prevents the column from being available to the column header.
-- CHART: {
--   columns: ["Name", "Hidden"],
--   type: "ColumnChart"
-- }
-- FILTER: {
--   filter: "hide",
--   column: "Hidden"
-- }

SELECT 'Test' AS 'Name', 200 AS 'Hidden';

This gives an error of "Not enough columns given to draw the requested chart" rather than rendering the chart as expected. Without the hide filter being applied the chart works fine.

[doekia]

Any progress or estimated time on this one?