Continuing the work from #2828, #2841, #2846, and #2852. This is probably my last change in this area for a while.
Bubble charts can have bubbles of different sizes. Phpspreadsheet had not supported this. Openpyxl comes with sample code to generate such a chart. I was especially drawn to that solution because its namespace usage would have been unexpected before 2852. And it turned out to come with other surprises - use of absolute paths in the .rels files (PhpSpreadsheet expected only relative), use of a one-cell anchor to place the chart (PhpSpreadsheet expected two-cell anchor or absolute positioning), plaintext in the legend (Phpspreadsheet expected RichText), no cached values for chart data. Excel handles the file okay, and this PR makes sure PhpSpreadsheet does as well. This file is now Samples/Templates/32readwriteBubbleChart2, and is used for both generating a sample output file and in formal tests. A new sample in the 33* series demonstrates how to code these.
* Namespacing Part 3 - Charts
Charts still need some work, but they are now in good enough shape that the code that reads them can handle namespacing properly. Rather than a set of static routines, Reader/Xlsx/Chart needs to be changed to a regular object, with the relevant namespaces passed in the constructor. I am still looking for a test spreadsheet with non-standard namespacing for a full-blown test, but, in the meantime, the existing tests and samples will suffice. When I find a test case, I will certainly add it.
The resulting code is actually simpler than it had been because of the elimination of the need for a NamespacesMeta variable in all the function signatures. Because of that, enough errors disappeared from Phpstan that I decided to just finish that job - its baseline file now dips below 5,000 lines.
* Update Change Log
Need to document many chart changes.
* Eliminate Corruption in Surface Chart Samples
Fix#2763 (bubble charts were fixed earlier).
* Improvement in Testing for Numeric Values
The original proposal was to test for numeric values by checking whether the format was NUMERIC or DATE. This is pretty inflexible, and left open a wide gap concerning what to do with GENERAL. Changed to allow the user to set a `numeric` property at the same time as `axisNumberProperties`, eliminating these concerns. User can set property when chart is created (new test member Charts32CatAxValAxTest), or can set it when spreadsheet with chart is read (new method testCatAxValAx in Charts32XmlTest). Sample 33_Chart_create_scatter2 creates a slightly wider chart when `numeric` is set to true than it does when unset, but chart is otherwise the same.
Corrected a bug which occured twice in Chart. Methods getChartAxisX and getChartAxisY created a new Axis object if the chart pointer was null, but neglected to attach the new object to the chart. Thus, subsequent calls to the methods return different objects. Code is changed to attach the new Axis to the Chart.
Disabled it earlier because its reliance on an external site not under our control was causing problems. URL in spreadsheet is now changed to point to an image in phpspreadsheet.readthedocs.io, which should be more reliable. Test is re-enabled.
Fix#2840 (and also #2839 but that's Q&A, not an issue). Csv Reader does not populate cells which contain null string. This PR provides an option for the reader to store null strings as it does with any other string.
* More Chart Fixes
Taking up where #2828 left off. Most of the following changes are demonstrated in 32readwriteChartWithImages1:
- Adds support for "scheme" colors (because rgb, theme, and index colors just weren't enough for Excel) for DataSeriesValues. See issue #2299.
- For chart titles (including axis labels), rather than a font name, Excel supplies a 3-fold series of font names for Latin, East Asian, and Complex Scripts. New properties `latin`, `eastAsian`, and `complexScript` are added to the Font class. I frankly have no idea how, or even if, you can set these in Excel; my test case (sample 32readwriteScatterChart7) is a result of manually editing the XML.
- Add support for subscript/superscript to chart titles. This requires a new property `baseLine` in Font (positive=superscript negative=subscript baseline value says how high/low).
- Support for underscore with different scheme color than its text, using a new string property `uSchemeClr` in Font.
- Support for extra options for strikethrough, using a new string property `strikeType` in Font.
- Support for extra options for underscore type, using the existing string property `underline` in Font.
- I do not anticipate that any of the new Font properties will be used except for chart titles.
- If no default font overrides are found for a Rich Text element in chart titles, and no explicit font overrides are found for a Run under such an element, the font element of the Run is set to null.
- PhpSpreadsheet will always write a tag `a:pPr` and, underneath that, an empty tag `a:defRPr`, for default font settings for chart titles and axis labels. Combined with the previous bullet item, this will prevent PhpSpreadsheet from inadvertently overriding the Excel defaults (18 point bold Calibri for chart title, 10 point bold Calibri for axis labels).
- Axis labels will now be written to XML in the same manner as chart titles. Among other considerations, this means that they can now have colors. Fix#2700. Supersedes PR #2701. Demonstrated in sample 32readwriteStockChart5.
* Fix Some Chart Corruption
Fix#2817, where @bridgeplayr gives an excellent description of the problem and how it should be solved.
* Fix Bubble Charts
Sample produced corrupt output - see issue #2763. After a lot of research, solution was just re-ordering of parameters in a single function call.
Bubble 3D had not been supported at all. It is now.
Surface Charts remain corrupted.
This test has always been problematic in that it depends on an external site not under the control of PhpSpreadsheet, and can therefore break at any time. As it has done this morning. Disable it until a better test is available.
* Some Fixes for Scatter Charts
Chart issues have been pouring in recently. This is a partial response to issue #2762. It implements "no joins" for scatter charts, as well as having the reader and writer handle "point size", "line width", and "color" for markers. A new boolean property `scatterLines`, with setter and getter, is added to DataSeriesValues to handle joins (default is true which means scatter plot points *are* joined by lines). Some, but not yet all, default font properties for the chart title are handled (color and, surprisingly, font name present challenges).
With these changes, sample 32readwriteScatterChart1.xlsx now looks closer to its source. There are still some differences (x-axis changes), but I think this change is already large enough. I can work on the other problems later.
The code for reading charts has not yet been converted to be namespace aware. Having a tiny island of aware code in a sea of unaware makes no sense to me, so some of the new code is likewise unaware. I hope to be able to get to it eventually, but, among other considerations, it is difficult to generate suitable test cases.
* Add Formal Tests
Essentially the same as the corresponding Samples, but with formal assertions.
* Clean Up Some Code in Reader/Xlsx/Chart
Having added code to support default font attributes as well as element-specific font attributes for chart captions, there was duplicated code between the default and specific sections. I hope that this PR makes the code easier to follow.
* Add Support for Font Name and Color to XLSX Chart Titles
XML layout for these in new files differs from what program was expecting. Not sure if program expectations were wrong, or if this is a change to Excel since initial development.
* Minor Improvement
Handle theoretical case where Chart title has text but no font information.
* Support Bezier Curve and Scaling of X-Axis on Scatter Plot
For Bezier, need to specify `<c:smooth>` tag in addition to already supplied `<c:scatterStyle val="smoothMarker">`
For X-Axis, scatter needs to supply both X and y axis as `<c:valAx>` rather than `<c:catAx>` for X.
Tomas Votruba
oleibman
Mark Baker
MarkBaker