Fix#4192. Although that issue can be dealt with by changing user code, it would be better to fix it within PhpSpreadsheet. A cloned worksheet may have a pointer to a spreadsheet to which it is not attached. Code can assume it does belong to the spreadsheet, and throw an exception when the spreadsheet cannot find the worksheet in question. It may also not throw an exception when it should.
In my comments to the issue, I was concerned that adding in the needed protection would add overhead to an extremely common situation (setting a cell's value) in order to avoid a pretty rare problem. However, there are problems with both the accuracy and efficiency of the existing code, and I think any performance losses caused by the additional checks will be offset by the performance gains and accuracy of the new code.
Spreadsheet `getIndex` attempts to find the index of a worksheet within its spreadsheet collection. It does so by comparing the hash codes of each sheet in its collection with the hash code of the sheet it is looking for. Its major problem problem is performance-related, namely that it recomputes the hash code of the target sheet with each iteration.
A more severe problem is the accuracy of the hash code. It generates this by hashing together the sheet title, the string range of its auto-filter, and a character representation of whether sheet protection is enabled. Title should definitely be part of the calculation (it must be unique for all sheets attached to a spreadsheet), but it is not clear why this subset of the other properties of Worksheet is used. It tries to save some cycles by using a `dirty` property to indicate whether re-hashing is necessary. It sets that property whenever the title changes, or when `setProtection` is called. So, it doesn't set it when auto-filter changes, and you can easily bypass `setProtection` when changing any of the `Protection` properties. Not to mention the many other properties of worksheet that can be changed. Additionally, if you clone a worksheet, the clone and the original will have the same hash code, which can lead to problems:
```php
$clone = clone $original;
$spreadsheet->getSheet($spreadsheet->getIndex($clone))
->setCellValue('A1', 100);
```
That code will change the value of A1 in the original, not the clone.
The `hash` property in Worksheet will now be calculated immediately when the object is constructed or cloned or unserialized. It will not be recalculated, and there is no longer a need for the `dirty` property, which is removed. Hash will be generated by spl_object_id, which was designed for this purpose. (So was spl_object_hash, but many online references suggest that \_id performs much better than \_hash.) Our problem example above will now throw an Exception, as it should, rather than changing the wrong cell. `setValueExplicit`, the problem in the original issue, will now test that the worksheet is attached to the spreadsheet before doing any style manipulation. In order that this not be a breaking change, `getHashCode` will continue to return string, but it is deprecated in favor of `getHashInt`, and Worksheet will no longer implement IComparable to facilitate the deprecation.
I had a vague hope that this change might help with issue #641. It doesn't.
See #4161. The best way to future-proof is to set the escape character to null string, and set testAutoDetect to false before reading. However, depending on the file being read, this may lead to different results than expected. This will be unavoidable because Php itself will change. This PR adds a new static method `affectedByPhp9` to Csv Reader. This can be used to identify in advance whether an input file will be affected by the changes. This will allow users to identify problems in advance, and prepare for how they might be handled.
Fix#2157. Excel 2003 format allows some things which a real Xml parser would reject. In particular, it permits Html entities, and leading whitespace. Change Xml Reader to do likewise.
Fix#1395, a 2020 issue which had been marked stale and is now re-opened. Static valueBinder property of Cell isn't ideal. It would be more flexible to make it a dynamic property of the spreadsheet. Static property will continue to be used, but dynamic property will be used first if it is set. Readers will also be changed to add a valueBinder property which they pass to the spreadsheet; however, it will make a difference only for Csv/Html/Slk, since the other readers use setValueExplicit which ignores valueBinder.
Documentation is updated in several places to note that dynamic property is preferred over static.
oleibman
yingshanghuangqiao