Problem

An ExcelWriter-generated file with charts displays correctly when opened in Excel, but when the same file is opened on an iPad or iPhone, the charts are missing from the file. There are two causes for this behavior:

1. The chart type is not supported by iOS. – Some chart types are not supported in iOS and will never appear when viewed on an iPad or iPhone, regardless of whether the file was created in Excel or ExcelWriter. An example of this is the “bubble chart.” This is an issue with iOS mobile applications – not ExcelWriter.
2. Charts in files generated by ExcelWriter v8.2 and earlier are not visible when viewed on iOS devices. – These chart types are supported in iOS and appear correctly on iPads or iPhones when the charts were created in Excel. If the file was generated by ExcelWriter, the charts are missing when viewed on iOS mobile devices. This is a known issue and was resolved in OfficeWriter 8.3.

This article describes why the second scenario occurs and the expected behavior when viewing charts created by OfficeWriter 8.3 or later.

Solution

When a workbook is opened in Excel, all of the cell values are updated based on the current state of the file. Excel caches these most recent cell values and writes them out to the file. Many mobile apps or applications with a “preview” functionality where the file is locked from being updated, do not have the ability to recalculate the cell values and rely on those cached values to render the rest of the file, including charts.

For iOS devices specifically, if the cached cell values are not available, most applications will not render the charts at all. ExcelWriter was not writing out cached values for the cells. Starting in OfficeWriter 8.3, ExcelWriter will copy the cell values to the cached field. This allows iOS applications to render the charts.

Limitations of Rendering Charts

In certain cases, the charts will be visible but may not look as expected. This is due to limitations in ExcelWriter’s ability to write out the cached values. For more information, please see Charts in ExcelWriter files not rendering correctly outside of Excel.