Disable autosave via Excel office.js addin

Gianluca Bisceglie 6

Our Addin performs thousand of cell changes in a loop.

The problem is that Excel autosave, especially in Excel 365, kicks in at every cell change and becomes the bottleneck.

We could not find ways to disable autosave from office.js API.

Any suggestions on how to work around it?

Thanks.

Raymond Lu 1 Reputation point

2021-05-20T12:26:49.727+00:00

Thanks for reporting this issue, You mentioned that autosave kicks in every cell change, would you please share with us what are the content in your workbook? I would like to learn more about the issue you met.
Gianluca Bisceglie 6 Reputation points

2021-05-20T13:41:02.13+00:00

Hi @Raymond Lu

The workbook is an ordinary workbook with 1 input cell and anoutput cell.

For example, let A1 be 2 and let B1 be = 2*A1

If you have a JS addin that needs to change A1 and capture the value of B1, you will see that Excel365 will autosave at every recalculation.

Now imagine what happens if the addin changes 1 thousand values in A1 in a loop. Excel freezes and you can see "Saving..." forever. Saving, creating versions and updating UI at every recalculation kills the performance of the addin.

Excel desktop does not autosave at every recalculation but it is important for the addin to disable and re-enable autosave and UI updates before and after the algorithm runs.
Gianluca Bisceglie 6 Reputation points

2021-05-20T13:42:45.883+00:00

The workbook is an ordinary workbook with one input cell and one output cell.

For example, let A1 be 2 and let B1 be = 2*A1

If you have a JS addin that changes A1 and pushes the value of B1 to an array, you will see that Excel365 will autosave at every recalculation.

Now imagine what happens when the addin changes 1 thousand values in A1 in a loop. Excel freezes and you can see "Saving..." forever. Saving, creating versions and updating UI at every recalculation kills the performance of the addin. Like for VSTO, also office.js should allow to talk to the object model to avoid performance bottlenecks.

Excel desktop does not autosave at every recalculation but it is important for the addin to disable and re-enable autosave and UI updates before and after the algorithm runs.
Raymond Lu 1 Reputation point

2021-05-24T03:18:10.877+00:00
There is a chance to suspend the calculation, would you please try the following 2 APIs?

suspendApiCalculationUntilNextSync() suspendScreenUpdatingUntilNextSync()

The document can be found at
https://learn.microsoft.com/en-us/javascript/api/excel/excel.application?view=excel-js-preview#suspendApiCalculationUntilNextSync__

https://learn.microsoft.com/en-us/javascript/api/excel/excel.application?view=excel-js-preview#suspendScreenUpdatingUntilNextSync__
Gianluca Bisceglie 6 Reputation points

2021-05-24T05:30:50.527+00:00

Hi @Raymond Lu

We have already tried both of them but calls to context.sync(), to extract the values, force UI updates. We would need a session-level UI suspension.

Please see https://github.com/OfficeDev/office-js/issues/1826#issuecomment-836313764

Can you suggest another approach while you make this API avabailable?
Gianluca Bisceglie 6 Reputation points

2021-05-26T12:07:25.04+00:00

This is about autosave, which kicks in when a cell is changed, especially in Office 365.

Besides, a "NextSync()" is necessary to read the output value so it reactivate UI at every change.
Oleksandr Reznichenko 0 Reputation points

2024-10-02T08:07:56.3066667+00:00

Are there any more suggestions on how to cope with AutoSave ?

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Disable autosave via Excel office.js addin

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