When reading spreadsheets, Spout should be able to return formatted dates, as shown when opened with Excel for instance.
It currently only returns DateTime/DateInterval objects, making it impossible to read + write, as the Writer does not accept objects.
Instead of relying on the ID, sheets should be retrieved in the order they appear in the file.
Workbook.xml describes the correct order.
This allows the reader to read data in the correct order when sheets have been manually moved after creation.
Some software generate [Content_Types].xml file with sheets definition in random order.
Instead of having the first sheet (id = 1) defined first, it may be defined in 3rd position.
Therefore, to read the file in the correct order, sheets order need to be fixed.
Although Excel has a Date type, older Excel versions use numeric values to store dates.
The value represents the number of days since Jan 1st, 1900.
The only way to tell if the value is a number or a date is to look at the styles.xml and check if the cell has date formatting.
Spout can now read ODS files.
It's on par with the XLSX reader. The only difference is that the row iterator cannot be rewound.
It supports the different output formats from LibreOffice and Excel, skipping extra rows/cells if needed.
Instead of the hasNext() / next() syntax, readers now implements the PHP iterator pattern.
It allows readers to be used with a foreach() loop.
All readers now share the same structure (CSV is treated as having exactly one sheet):
- one concrete Reader
- one SheetIterator, exposed by the Reader
- one or more Sheets, returned at every iteration
- one RowIterator, exposed by the Sheet
Introducing the concept of sheets for CSV may be kind of confusing but it makes Spout way more consistent.
Also, this confusion may be resolved by creating a wrapper around the readers if needed.
-- This commit does not delete the old files, not change the folder structure for Writers. This will be done in another commit.
