oleibman
9fc8e501b8
This is a partial response to issue #4282. The actual logic to implement GROUPBY is probably very complicated. And, even worse, Excel has thrown a whole new way of (internally) specifying one of the arguments into the mix. That argument is a function name, expressed not as a mapped integer (as SUBTOTAL does), nor even as a string, but as the unquoted function name prefixed by `_xleta.`. And, unlike its `_xlfn.` and `_xlws.` predecessors, it is difficult to figure out when the new prefix needs to be added, and when it needs to be ignored. I am not even going to attempt that task with this ticket. So, what does this change do? Like earlier attempts to introduce limited functionality (such as with form controls), it is there so that using GROUPBY can be passed through - you can load a spreadsheet that contains it, and save it to a new spreadsheet, and the function and its results are preserved. Some cautionary notes. Dynamic arrays must be enabled (the function makes no sense without doing that). Changing any of the inputs used in the function may result in internal inconsistencies between PhpSpreadsheet and Excel; this is especially so if the dimensions of the returned array change as a result of changes to the input data. The programmer can avoid some of these problems by changing the formulatAttributes of the cell where the function is used; this may be difficult to do in practice. Oh, yes, using the GROUPBY cell as an argument in another formula will probably lead to problems. Finally, I confess that part of this solution looks awfully kludgey to me. With its limitations and those cautions, is it worth proceeding with this change? My gut feel is that it is more useful to proceed than not. However, I will give others the opportunity to weigh in. I will wait at least a couple of weeks into the new year before proceeding with this.
PhpSpreadsheet
PhpSpreadsheet is a library written in pure PHP and offers a set of classes that allow you to read and write various spreadsheet file formats such as Excel and LibreOffice Calc.
Installation
See the install instructions.
Documentation
Read more about it, including install instructions, in the official documentation. Or check out the API documentation.
Please ask your support questions on StackOverflow, or have a quick chat on Gitter.
Patreon
I am now running a Patreon to support the work that I do on PhpSpreadsheet.
Supporters will receive access to articles about working with PhpSpreadsheet, and how to use some of its more advanced features.
Posts already available to Patreon supporters:
- The Dating Game
- A look at how MS Excel (and PhpSpreadsheet) handle date and time values.
- Looping the Loop
- Advice on Iterating through the rows and cells in a worksheet.
And for Patrons at levels actively using PhpSpreadsheet:
- Behind the Mask
- A look at Number Format Masks.
The Next Article (currently Work in Progress):
- Formula for Success
- How to debug formulae that don't produce the expected result.
My aim is to post at least one article each month, taking a detailed look at some feature of MS Excel and how to use that feature in PhpSpreadsheet, or on how to perform different activities in PhpSpreadsheet.
Planned posts for the future include topics like:
- Tables
- Structured References
- AutoFiltering
- Array Formulae
- Conditional Formatting
- Data Validation
- Value Binders
- Images
- Charts
After a period of six months exclusive to Patreon supporters, articles will be incorporated into the public documentation for the library.
PHPExcel vs PhpSpreadsheet ?
PhpSpreadsheet is the next version of PHPExcel. It breaks compatibility to dramatically improve the code base quality (namespaces, PSR compliance, use of latest PHP language features, etc.).
Because all efforts have shifted to PhpSpreadsheet, PHPExcel will no longer be maintained. All contributions for PHPExcel, patches and new features, should target PhpSpreadsheet master branch.
Do you need to migrate? There is an automated tool for that.
License
PhpSpreadsheet is licensed under MIT.